Impact of Euro-American settlement on a riparian landscape in northeast Iowa, midwestem USA: an integrated approach based on historical evidence, floodplain sediments, fossil pollen, plant macrofossils and insects
Identifieur interne : 004D80 ( Istex/Corpus ); précédent : 004D79; suivant : 004D81Impact of Euro-American settlement on a riparian landscape in northeast Iowa, midwestem USA: an integrated approach based on historical evidence, floodplain sediments, fossil pollen, plant macrofossils and insects
Auteurs : R. G. Baker ; D. P. Schwert ; E. A. Bettis ; C. A. ChumbleySource :
- Holocene (Sevenoaks) [ 0959-6836 ] ; 1993-12.
English descriptors
- KwdEn :
- Adjacent channel, Aggradation, Alluvium, American geographers, Aquatic, Aquatic plants, Assemblage, Beetle, Beetle fauna, Bettis, Birks, Cattle dung, Channel belt, Chumbley, Clayton county, Coleoptera, Cultural landscape, Curculionidae, Dakota state university, Drainage basin, Driftless area, Dryopoid, Dryopoid beetles, Entomological society, Environmental entomology, European settlement, Fauna, Floodplain, Floodplain sediments, Fossil, General land office survey, Geological survey bureau, Ground beetle, Ground plants, High water quality, Historic time, Historical alluvium, Historical deposits, Historical evidence, Historical period, Historical records, Historical sedimentation, Holocene, Holocene vegetation, Host plants, Human activities, Human disturbance, Human impact, Infiltration capacity, Insect fauna, Iowa, Iowa city, Iowa department, Iowa state, Iowa state census, Iowa state university soil survey laboratory, John wiley, Land clearance, Late bronze, Macrofossils, Mdash, Meander belt, Modern samples, Modern stream, Modern time, Natural landscapes, Natural resources, Nearctic species, Northeast iowa, Northeastern, Northeastern iowa, Northwestern minnesota, Open grasslands, Opuscula entomologica supplementum, Organic carbon, Organic carbon content, Plant macrofossils, Pollen diagram, Pollen percentages, Poor conservation practices, Postsettlement, Postsettlement assemblages, Postsettlement deposits, Postsettlement samples, Postsettlement species, Presettlement, Presettlement alluvium, Presettlement assemblages, Presettlement sites, Presettlement values, Quaternary, Quaternary research, Radiocarbon ages, Radiocarbon dates, Riparian, Riparian landscape, River avon, Roberts creek, Roberts creek basin, Roberts creek drainage basin, Ruderal, Ruderal plants, Ruderal species, Runoff, Scarabaeid, Sediment, Sediment delivery, Sedimentation, Soil erosion, Soil survey staff, Standard procedures, Stream banks, Stream behaviour, Taxon, Terrestrial beetle taxa, Upland, Upper part, Valley floor, Vegetation, Water quality, Water table, Weevil.
- Teeft :
- Adjacent channel, Aggradation, Alluvium, American geographers, Aquatic, Aquatic plants, Assemblage, Beetle, Beetle fauna, Bettis, Birks, Cattle dung, Channel belt, Chumbley, Clayton county, Coleoptera, Cultural landscape, Curculionidae, Dakota state university, Drainage basin, Driftless area, Dryopoid, Dryopoid beetles, Entomological society, Environmental entomology, European settlement, Fauna, Floodplain, Floodplain sediments, Fossil, General land office survey, Geological survey bureau, Ground beetle, Ground plants, High water quality, Historic time, Historical alluvium, Historical deposits, Historical evidence, Historical period, Historical records, Historical sedimentation, Holocene, Holocene vegetation, Host plants, Human activities, Human disturbance, Human impact, Infiltration capacity, Insect fauna, Iowa, Iowa city, Iowa department, Iowa state, Iowa state census, Iowa state university soil survey laboratory, John wiley, Land clearance, Late bronze, Macrofossils, Mdash, Meander belt, Modern samples, Modern stream, Modern time, Natural landscapes, Natural resources, Nearctic species, Northeast iowa, Northeastern, Northeastern iowa, Northwestern minnesota, Open grasslands, Opuscula entomologica supplementum, Organic carbon, Organic carbon content, Plant macrofossils, Pollen diagram, Pollen percentages, Poor conservation practices, Postsettlement, Postsettlement assemblages, Postsettlement deposits, Postsettlement samples, Postsettlement species, Presettlement, Presettlement alluvium, Presettlement assemblages, Presettlement sites, Presettlement values, Quaternary, Quaternary research, Radiocarbon ages, Radiocarbon dates, Riparian, Riparian landscape, River avon, Roberts creek, Roberts creek basin, Roberts creek drainage basin, Ruderal, Ruderal plants, Ruderal species, Runoff, Scarabaeid, Sediment, Sediment delivery, Sedimentation, Soil erosion, Soil survey staff, Standard procedures, Stream banks, Stream behaviour, Taxon, Terrestrial beetle taxa, Upland, Upper part, Valley floor, Vegetation, Water quality, Water table, Weevil.
Abstract
European settlement and attendant forest clearance and agricultural activities in northeastern Iowa caused changes in the landscape, vegetation, insect fauna and water quality unequalled in rate and magnitude since the melting of Wisconsinan glaciers. Historical documents show that the upper part of the Roberts Creek drainage basin was settled between AD 1840 and 1856, and the area was under intensive cultivation by 1880. Extensive soil erosion beginning at this time resulted in increased runoff and more frequent flooding; aggradation rates increased by one to two orders of magnitude over those in presettlement times, and the entire floodplain was covered with up to 1 m of sediment. Channel widening between about 1880 and 1930 allowed the stream to accommodate greater floods, overbank deposition decreased, and further deposits were restricted mostly to the channel belt. The presettlement vegetation was a stable mix of wet meadows and riparian shrubs on the floodplain, a rich aquatic community in the stream, and oak savanna on the valley walls and upland. Disturbance from soil erosion, floodplain erosion and floodplain deposition almost completely replaced both lowland and upland communities with ruderal (disturbed ground) plants, many of them introduced weeds. Regional insect communities were simultaneously affected by changes in land use. The presettlement aquatic beetle fauna was dominated by species of dryopoid beetles that today inhabit only streams of high water quality. Terrestrial beetle taxa included species of undisturbed grasslands and riparian forest. The changes in the landscape resulted in a decrease in the diversity of terrestrial beetle taxa and caused the near total elimination of dryopoid beetles in stream waters. Dominating the historic assemblages are beetles associated with dung, polluted waters and cultivated plants, including host-specific immigrant beetle species that are associated with immigrant plant species.
Url:
DOI: 10.1177/095968369300300403
Links to Exploration step
ISTEX:9B6AE279BE1A6C106F2CDBB822870FBB56258972Le document en format XML
<record><TEI wicri:istexFullTextTei="biblStruct"><teiHeader><fileDesc><titleStmt><title xml:lang="en">Impact of Euro-American settlement on a riparian landscape in northeast Iowa, midwestem USA: an integrated approach based on historical evidence, floodplain sediments, fossil pollen, plant macrofossils and insects</title><author wicri:is="90%"><name sortKey="Baker, R G" sort="Baker, R G" uniqKey="Baker R" first="R. G." last="Baker">R. G. Baker</name><affiliation><mods:affiliation>Department of Geology, University of Iowa, Iowa City, Iowa 52242-1379, USA</mods:affiliation></affiliation></author><author wicri:is="90%"><name sortKey="Schwert, D P" sort="Schwert, D P" uniqKey="Schwert D" first="D. P." last="Schwert">D. P. 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G." last="Baker">R. G. Baker</name><affiliation><mods:affiliation>Department of Geology, University of Iowa, Iowa City, Iowa 52242-1379, USA</mods:affiliation></affiliation></author><author wicri:is="90%"><name sortKey="Schwert, D P" sort="Schwert, D P" uniqKey="Schwert D" first="D. P." last="Schwert">D. P. Schwert</name><affiliation><mods:affiliation>Department of Geosciences, North Dakota State University, Fargo, North Dakota 58105-5517, USA</mods:affiliation></affiliation></author><author wicri:is="90%"><name sortKey="Bettis, E A" sort="Bettis, E A" uniqKey="Bettis E" first="E. A." last="Bettis">E. A. Bettis</name><affiliation><mods:affiliation>Iowa Department of Natural Resources, Geological Survey Bureau, 123 N Capitol, Iowa City, Iowa 52242, USA</mods:affiliation></affiliation></author><author wicri:is="90%"><name sortKey="Chumbley, C A" sort="Chumbley, C A" uniqKey="Chumbley C" first="C. A." last="Chumbley">C. A. Chumbley</name><affiliation><mods:affiliation>412 Highland Avenue, Iowa City, Iowa 52242, USA</mods:affiliation></affiliation></author></analytic><monogr></monogr><series><title level="j">Holocene (Sevenoaks)</title><idno type="ISSN">0959-6836</idno><idno type="eISSN">1477-0911</idno><imprint><publisher>Sage Publications</publisher><pubPlace>Sage CA: Thousand Oaks, CA</pubPlace><date type="published" when="1993-12">1993-12</date><biblScope unit="volume">3</biblScope><biblScope unit="issue">4</biblScope><biblScope unit="page" from="314">314</biblScope><biblScope unit="page" to="323">323</biblScope></imprint><idno type="ISSN">0959-6836</idno></series></biblStruct></sourceDesc><seriesStmt><idno type="ISSN">0959-6836</idno></seriesStmt></fileDesc><profileDesc><textClass><keywords scheme="KwdEn" xml:lang="en"><term>Adjacent channel</term><term>Aggradation</term><term>Alluvium</term><term>American geographers</term><term>Aquatic</term><term>Aquatic plants</term><term>Assemblage</term><term>Beetle</term><term>Beetle fauna</term><term>Bettis</term><term>Birks</term><term>Cattle dung</term><term>Channel belt</term><term>Chumbley</term><term>Clayton county</term><term>Coleoptera</term><term>Cultural landscape</term><term>Curculionidae</term><term>Dakota state university</term><term>Drainage basin</term><term>Driftless area</term><term>Dryopoid</term><term>Dryopoid beetles</term><term>Entomological society</term><term>Environmental entomology</term><term>European settlement</term><term>Fauna</term><term>Floodplain</term><term>Floodplain sediments</term><term>Fossil</term><term>General land office survey</term><term>Geological survey bureau</term><term>Ground beetle</term><term>Ground plants</term><term>High water quality</term><term>Historic time</term><term>Historical alluvium</term><term>Historical deposits</term><term>Historical evidence</term><term>Historical period</term><term>Historical records</term><term>Historical sedimentation</term><term>Holocene</term><term>Holocene vegetation</term><term>Host plants</term><term>Human activities</term><term>Human disturbance</term><term>Human impact</term><term>Infiltration capacity</term><term>Insect fauna</term><term>Iowa</term><term>Iowa city</term><term>Iowa department</term><term>Iowa state</term><term>Iowa state census</term><term>Iowa state university soil survey laboratory</term><term>John wiley</term><term>Land clearance</term><term>Late bronze</term><term>Macrofossils</term><term>Mdash</term><term>Meander belt</term><term>Modern samples</term><term>Modern stream</term><term>Modern time</term><term>Natural landscapes</term><term>Natural resources</term><term>Nearctic species</term><term>Northeast iowa</term><term>Northeastern</term><term>Northeastern iowa</term><term>Northwestern minnesota</term><term>Open grasslands</term><term>Opuscula entomologica supplementum</term><term>Organic carbon</term><term>Organic carbon content</term><term>Plant macrofossils</term><term>Pollen diagram</term><term>Pollen percentages</term><term>Poor conservation practices</term><term>Postsettlement</term><term>Postsettlement assemblages</term><term>Postsettlement deposits</term><term>Postsettlement samples</term><term>Postsettlement species</term><term>Presettlement</term><term>Presettlement alluvium</term><term>Presettlement assemblages</term><term>Presettlement sites</term><term>Presettlement values</term><term>Quaternary</term><term>Quaternary research</term><term>Radiocarbon ages</term><term>Radiocarbon dates</term><term>Riparian</term><term>Riparian landscape</term><term>River avon</term><term>Roberts creek</term><term>Roberts creek basin</term><term>Roberts creek drainage basin</term><term>Ruderal</term><term>Ruderal plants</term><term>Ruderal species</term><term>Runoff</term><term>Scarabaeid</term><term>Sediment</term><term>Sediment delivery</term><term>Sedimentation</term><term>Soil erosion</term><term>Soil survey staff</term><term>Standard procedures</term><term>Stream banks</term><term>Stream behaviour</term><term>Taxon</term><term>Terrestrial beetle taxa</term><term>Upland</term><term>Upper part</term><term>Valley floor</term><term>Vegetation</term><term>Water quality</term><term>Water table</term><term>Weevil</term></keywords><keywords scheme="Teeft" xml:lang="en"><term>Adjacent channel</term><term>Aggradation</term><term>Alluvium</term><term>American geographers</term><term>Aquatic</term><term>Aquatic plants</term><term>Assemblage</term><term>Beetle</term><term>Beetle fauna</term><term>Bettis</term><term>Birks</term><term>Cattle dung</term><term>Channel belt</term><term>Chumbley</term><term>Clayton county</term><term>Coleoptera</term><term>Cultural landscape</term><term>Curculionidae</term><term>Dakota state university</term><term>Drainage basin</term><term>Driftless area</term><term>Dryopoid</term><term>Dryopoid beetles</term><term>Entomological society</term><term>Environmental entomology</term><term>European settlement</term><term>Fauna</term><term>Floodplain</term><term>Floodplain sediments</term><term>Fossil</term><term>General land office survey</term><term>Geological survey bureau</term><term>Ground beetle</term><term>Ground plants</term><term>High water quality</term><term>Historic time</term><term>Historical alluvium</term><term>Historical deposits</term><term>Historical evidence</term><term>Historical period</term><term>Historical records</term><term>Historical sedimentation</term><term>Holocene</term><term>Holocene vegetation</term><term>Host plants</term><term>Human activities</term><term>Human disturbance</term><term>Human impact</term><term>Infiltration capacity</term><term>Insect fauna</term><term>Iowa</term><term>Iowa city</term><term>Iowa department</term><term>Iowa state</term><term>Iowa state census</term><term>Iowa state university soil survey laboratory</term><term>John wiley</term><term>Land clearance</term><term>Late bronze</term><term>Macrofossils</term><term>Mdash</term><term>Meander belt</term><term>Modern samples</term><term>Modern stream</term><term>Modern time</term><term>Natural landscapes</term><term>Natural resources</term><term>Nearctic species</term><term>Northeast iowa</term><term>Northeastern</term><term>Northeastern iowa</term><term>Northwestern minnesota</term><term>Open grasslands</term><term>Opuscula entomologica supplementum</term><term>Organic carbon</term><term>Organic carbon content</term><term>Plant macrofossils</term><term>Pollen diagram</term><term>Pollen percentages</term><term>Poor conservation practices</term><term>Postsettlement</term><term>Postsettlement assemblages</term><term>Postsettlement deposits</term><term>Postsettlement samples</term><term>Postsettlement species</term><term>Presettlement</term><term>Presettlement alluvium</term><term>Presettlement assemblages</term><term>Presettlement sites</term><term>Presettlement values</term><term>Quaternary</term><term>Quaternary research</term><term>Radiocarbon ages</term><term>Radiocarbon dates</term><term>Riparian</term><term>Riparian landscape</term><term>River avon</term><term>Roberts creek</term><term>Roberts creek basin</term><term>Roberts creek drainage basin</term><term>Ruderal</term><term>Ruderal plants</term><term>Ruderal species</term><term>Runoff</term><term>Scarabaeid</term><term>Sediment</term><term>Sediment delivery</term><term>Sedimentation</term><term>Soil erosion</term><term>Soil survey staff</term><term>Standard procedures</term><term>Stream banks</term><term>Stream behaviour</term><term>Taxon</term><term>Terrestrial beetle taxa</term><term>Upland</term><term>Upper part</term><term>Valley floor</term><term>Vegetation</term><term>Water quality</term><term>Water table</term><term>Weevil</term></keywords></textClass><langUsage><language ident="en">en</language></langUsage></profileDesc></teiHeader><front><div type="abstract" xml:lang="en">European settlement and attendant forest clearance and agricultural activities in northeastern Iowa caused changes in the landscape, vegetation, insect fauna and water quality unequalled in rate and magnitude since the melting of Wisconsinan glaciers. Historical documents show that the upper part of the Roberts Creek drainage basin was settled between AD 1840 and 1856, and the area was under intensive cultivation by 1880. Extensive soil erosion beginning at this time resulted in increased runoff and more frequent flooding; aggradation rates increased by one to two orders of magnitude over those in presettlement times, and the entire floodplain was covered with up to 1 m of sediment. Channel widening between about 1880 and 1930 allowed the stream to accommodate greater floods, overbank deposition decreased, and further deposits were restricted mostly to the channel belt. The presettlement vegetation was a stable mix of wet meadows and riparian shrubs on the floodplain, a rich aquatic community in the stream, and oak savanna on the valley walls and upland. Disturbance from soil erosion, floodplain erosion and floodplain deposition almost completely replaced both lowland and upland communities with ruderal (disturbed ground) plants, many of them introduced weeds. Regional insect communities were simultaneously affected by changes in land use. The presettlement aquatic beetle fauna was dominated by species of dryopoid beetles that today inhabit only streams of high water quality. Terrestrial beetle taxa included species of undisturbed grasslands and riparian forest. The changes in the landscape resulted in a decrease in the diversity of terrestrial beetle taxa and caused the near total elimination of dryopoid beetles in stream waters. Dominating the historic assemblages are beetles associated with dung, polluted waters and cultivated plants, including host-specific immigrant beetle species that are associated with immigrant plant species.</div></front></TEI><istex><corpusName>sage</corpusName><keywords><teeft><json:string>beetle</json:string><json:string>presettlement</json:string><json:string>floodplain</json:string><json:string>alluvium</json:string><json:string>holocene</json:string><json:string>taxon</json:string><json:string>postsettlement</json:string><json:string>coleoptera</json:string><json:string>historical alluvium</json:string><json:string>fossil</json:string><json:string>quaternary</json:string><json:string>macrofossils</json:string><json:string>aquatic</json:string><json:string>ruderal</json:string><json:string>riparian</json:string><json:string>weevil</json:string><json:string>mdash</json:string><json:string>roberts creek</json:string><json:string>roberts creek basin</json:string><json:string>birks</json:string><json:string>curculionidae</json:string><json:string>scarabaeid</json:string><json:string>chumbley</json:string><json:string>aggradation</json:string><json:string>dryopoid</json:string><json:string>bettis</json:string><json:string>valley floor</json:string><json:string>plant macrofossils</json:string><json:string>water quality</json:string><json:string>northeastern iowa</json:string><json:string>fauna</json:string><json:string>northeastern</json:string><json:string>ground plants</json:string><json:string>iowa city</json:string><json:string>insect fauna</json:string><json:string>driftless area</json:string><json:string>sedimentation</json:string><json:string>iowa</json:string><json:string>soil erosion</json:string><json:string>meander belt</json:string><json:string>quaternary research</json:string><json:string>clayton county</json:string><json:string>aquatic plants</json:string><json:string>modern samples</json:string><json:string>roberts creek drainage basin</json:string><json:string>sediment</json:string><json:string>upland</json:string><json:string>natural resources</json:string><json:string>ruderal species</json:string><json:string>natural landscapes</json:string><json:string>opuscula entomologica supplementum</json:string><json:string>european settlement</json:string><json:string>human activities</json:string><json:string>channel belt</json:string><json:string>postsettlement samples</json:string><json:string>dryopoid beetles</json:string><json:string>postsettlement deposits</json:string><json:string>river avon</json:string><json:string>vegetation</json:string><json:string>runoff</json:string><json:string>assemblage</json:string><json:string>riparian landscape</json:string><json:string>cultural landscape</json:string><json:string>iowa state census</json:string><json:string>historical records</json:string><json:string>historical period</json:string><json:string>nearctic species</json:string><json:string>historical sedimentation</json:string><json:string>general land office survey</json:string><json:string>radiocarbon ages</json:string><json:string>stream banks</json:string><json:string>geological survey bureau</json:string><json:string>standard procedures</json:string><json:string>soil survey staff</json:string><json:string>upper part</json:string><json:string>stream behaviour</json:string><json:string>pollen diagram</json:string><json:string>organic carbon</json:string><json:string>iowa state university soil survey laboratory</json:string><json:string>northeast iowa</json:string><json:string>adjacent channel</json:string><json:string>beetle fauna</json:string><json:string>presettlement values</json:string><json:string>organic carbon content</json:string><json:string>presettlement alluvium</json:string><json:string>poor conservation practices</json:string><json:string>infiltration capacity</json:string><json:string>sediment delivery</json:string><json:string>floodplain sediments</json:string><json:string>historical evidence</json:string><json:string>ruderal plants</json:string><json:string>presettlement sites</json:string><json:string>land clearance</json:string><json:string>historic time</json:string><json:string>modern time</json:string><json:string>modern stream</json:string><json:string>historical deposits</json:string><json:string>open grasslands</json:string><json:string>radiocarbon dates</json:string><json:string>presettlement assemblages</json:string><json:string>high water quality</json:string><json:string>host plants</json:string><json:string>postsettlement assemblages</json:string><json:string>dakota state university</json:string><json:string>postsettlement species</json:string><json:string>pollen percentages</json:string><json:string>cattle dung</json:string><json:string>terrestrial beetle taxa</json:string><json:string>drainage basin</json:string><json:string>late bronze</json:string><json:string>iowa state</json:string><json:string>northwestern minnesota</json:string><json:string>iowa department</json:string><json:string>human disturbance</json:string><json:string>holocene vegetation</json:string><json:string>john wiley</json:string><json:string>environmental entomology</json:string><json:string>american geographers</json:string><json:string>human impact</json:string><json:string>ground beetle</json:string><json:string>entomological society</json:string><json:string>water table</json:string></teeft></keywords><author><json:item><name>R.G. Baker</name><affiliations><json:string>Department of Geology, University of Iowa, Iowa City, Iowa 52242-1379, USA</json:string></affiliations></json:item><json:item><name>D.P. Schwert</name><affiliations><json:string>Department of Geosciences, North Dakota State University, Fargo, North Dakota 58105-5517, USA</json:string></affiliations></json:item><json:item><name>E.A. Bettis</name><affiliations><json:string>Iowa Department of Natural Resources, Geological Survey Bureau, 123 N Capitol, Iowa City, Iowa 52242, USA</json:string></affiliations></json:item><json:item><name>C.A. Chumbley</name><affiliations><json:string>412 Highland Avenue, Iowa City, Iowa 52242, USA</json:string></affiliations></json:item></author><subject><json:item><lang><json:string>eng</json:string></lang><value>Euro-American settlement</value></json:item><json:item><lang><json:string>eng</json:string></lang><value>human impact</value></json:item><json:item><lang><json:string>eng</json:string></lang><value>riparian landscape</value></json:item><json:item><lang><json:string>eng</json:string></lang><value>cultural landscape</value></json:item><json:item><lang><json:string>eng</json:string></lang><value>historical evidence</value></json:item><json:item><lang><json:string>eng</json:string></lang><value>floodplain sediments</value></json:item><json:item><lang><json:string>eng</json:string></lang><value>pollen</value></json:item><json:item><lang><json:string>eng</json:string></lang><value>macrofossils</value></json:item><json:item><lang><json:string>eng</json:string></lang><value>insects</value></json:item><json:item><lang><json:string>eng</json:string></lang><value>Iowa</value></json:item><json:item><lang><json:string>eng</json:string></lang><value>midwest.</value></json:item></subject><articleId><json:string>10.1177_095968369300300403</json:string></articleId><arkIstex>ark:/67375/M70-5L16Z0KV-C</arkIstex><language><json:string>eng</json:string></language><originalGenre><json:string>research-article</json:string></originalGenre><abstract>European settlement and attendant forest clearance and agricultural activities in northeastern Iowa caused changes in the landscape, vegetation, insect fauna and water quality unequalled in rate and magnitude since the melting of Wisconsinan glaciers. Historical documents show that the upper part of the Roberts Creek drainage basin was settled between AD 1840 and 1856, and the area was under intensive cultivation by 1880. Extensive soil erosion beginning at this time resulted in increased runoff and more frequent flooding; aggradation rates increased by one to two orders of magnitude over those in presettlement times, and the entire floodplain was covered with up to 1 m of sediment. Channel widening between about 1880 and 1930 allowed the stream to accommodate greater floods, overbank deposition decreased, and further deposits were restricted mostly to the channel belt. The presettlement vegetation was a stable mix of wet meadows and riparian shrubs on the floodplain, a rich aquatic community in the stream, and oak savanna on the valley walls and upland. Disturbance from soil erosion, floodplain erosion and floodplain deposition almost completely replaced both lowland and upland communities with ruderal (disturbed ground) plants, many of them introduced weeds. Regional insect communities were simultaneously affected by changes in land use. The presettlement aquatic beetle fauna was dominated by species of dryopoid beetles that today inhabit only streams of high water quality. Terrestrial beetle taxa included species of undisturbed grasslands and riparian forest. The changes in the landscape resulted in a decrease in the diversity of terrestrial beetle taxa and caused the near total elimination of dryopoid beetles in stream waters. Dominating the historic assemblages are beetles associated with dung, polluted waters and cultivated plants, including host-specific immigrant beetle species that are associated with immigrant plant species.</abstract><qualityIndicators><score>10</score><pdfWordCount>6381</pdfWordCount><pdfCharCount>42019</pdfCharCount><pdfVersion>1.4</pdfVersion><pdfPageCount>10</pdfPageCount><pdfPageSize>584 x 843 pts</pdfPageSize><refBibsNative>true</refBibsNative><abstractWordCount>289</abstractWordCount><abstractCharCount>1968</abstractCharCount><keywordCount>11</keywordCount></qualityIndicators><title>Impact of Euro-American settlement on a riparian landscape in northeast Iowa, midwestem USA: an integrated approach based on historical evidence, floodplain sediments, fossil pollen, plant macrofossils and insects</title><genre><json:string>research-article</json:string></genre><host><title>Holocene (Sevenoaks)</title><language><json:string>unknown</json:string></language><issn><json:string>0959-6836</json:string></issn><eissn><json:string>1477-0911</json:string></eissn><publisherId><json:string>HOL</json:string></publisherId><volume>3</volume><issue>4</issue><pages><first>314</first><last>323</last></pages><genre><json:string>journal</json:string></genre></host><namedEntities><unitex><date><json:string>1840s</json:string><json:string>1930</json:string><json:string>3500</json:string><json:string>8000</json:string><json:string>1920s</json:string><json:string>1993</json:string><json:string>1850</json:string><json:string>1000</json:string><json:string>1890</json:string><json:string>1850s</json:string><json:string>the nineteenth century</json:string><json:string>seventeenth century</json:string><json:string>1930s</json:string><json:string>1840</json:string><json:string>1880</json:string><json:string>1683</json:string><json:string>1874</json:string><json:string>3000</json:string><json:string>1830s</json:string></date><geogName><json:string>River Avon</json:string><json:string>region of Roberts Creek</json:string><json:string>Lake Superior</json:string><json:string>Lake Shagawa</json:string><json:string>Mississippi River</json:string><json:string>Roberts Creek</json:string></geogName><orgName><json:string>Iowa Department of Natural Resources, Geological Survey Bureau</json:string><json:string>University of Oklahoma</json:string><json:string>National Museum of Canada</json:string><json:string>Turkey River</json:string><json:string>University of Iowa, Iowa City</json:string><json:string>Quaternary Entomology Laboratory, North Dakota State University, Fargo, North Dakota</json:string><json:string>Biosystematics Research Centre, Agriculture Canada</json:string><json:string>University of Iowa Geology Department</json:string><json:string>Systematic Entomology Laboratory, USDA</json:string><json:string>Iowa State University</json:string><json:string>NSF Grants ATM</json:string></orgName><orgName_funder><json:string>NSF Grants ATM</json:string></orgName_funder><orgName_provider></orgName_provider><persName><json:string>Sally Domke</json:string><json:string>Joseph Krieg</json:string><json:string>R.G. Baker</json:string><json:string>Clayton County</json:string><json:string>A.L. Fisk</json:string><json:string>Cynthia Jensen</json:string><json:string>H.P. Brown</json:string><json:string>Soil Survey Staff</json:string><json:string>Anderson</json:string><json:string>E.A. Bettis</json:string><json:string>Division</json:string><json:string>R.S. Anderson</json:string><json:string>W.C. Johnson</json:string><json:string>D.P. Schwert</json:string><json:string>C.A. Chumbley</json:string><json:string>Gordon</json:string><json:string>General Land Office Survey of Wisconsin Territory</json:string></persName><placeName><json:string>Iowa City</json:string><json:string>United States</json:string><json:string>US</json:string><json:string>Krogstad</json:string><json:string>Europe</json:string><json:string>Japan</json:string><json:string>America</json:string><json:string>Warwickshire</json:string></placeName><ref_url></ref_url><ref_bibl><json:string>Ratcliffe, 1991</json:string><json:string>Sailer, 1983</json:string><json:string>Benton and Gray, 1925</json:string><json:string>Bettis and Littke, 1987</json:string><json:string>Brugham (1978)</json:string><json:string>Webb et al., 1983</json:string><json:string>Chumbley, 1989</json:string><json:string>Buckland and Kenward, 1973</json:string><json:string>Brown, 1976</json:string><json:string>Soil Survey Staff, 1975</json:string><json:string>Gleason and Cronquist (1963)</json:string><json:string>McLeod, 1980</json:string><json:string>Turnbull, 1980</json:string><json:string>Flegri et al. (1989)</json:string><json:string>Kennedy and Miller, 1990</json:string><json:string>Luff and Rushton, 1989</json:string><json:string>JohnsonCicalese et al., 1990</json:string><json:string>Bradbury and Waddington (1973)</json:string><json:string>Birks et al. (1976)</json:string><json:string>Smith, 1985</json:string><json:string>Puttler et al., 1973</json:string><json:string>Lindroth, 1966</json:string><json:string>Bousquet, 1990</json:string><json:string>Ashworth (1979)</json:string><json:string>Osborne, 1974</json:string><json:string>Iowa State Census, 1856</json:string><json:string>James (1991)</json:string><json:string>Tsukada, 1972</json:string><json:string>1968; Freitag, 1969</json:string><json:string>Dick and Tabatabai, 1977</json:string><json:string>McAndrews, 1988</json:string><json:string>Knox (1987)</json:string><json:string>Gleason and Cronquist, 1963</json:string><json:string>Gordon, 1985</json:string><json:string>Birks et al., 1988</json:string><json:string>1988; Kenward, 1976</json:string><json:string>Delcourt et al., 1986</json:string><json:string>Chumbley et al., 1990</json:string><json:string>The 1838</json:string><json:string>Walter et al., 1978</json:string><json:string>Birks et al., 1976</json:string><json:string>Bettis, 1984</json:string><json:string>Yeomans and Bremner, 1991</json:string><json:string>Knox, 1987</json:string><json:string>Cwynar et al., 1979</json:string><json:string>Hilsenoff, 1977</json:string><json:string>Lindroth, 1957</json:string></ref_bibl><bibl></bibl></unitex></namedEntities><ark><json:string>ark:/67375/M70-5L16Z0KV-C</json:string></ark><categories><wos><json:string>1 - 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Historical documents show that the upper part of the Roberts Creek drainage basin was settled between AD 1840 and 1856, and the area was under intensive cultivation by 1880. Extensive soil erosion beginning at this time resulted in increased runoff and more frequent flooding; aggradation rates increased by one to two orders of magnitude over those in presettlement times, and the entire floodplain was covered with up to 1 m of sediment. Channel widening between about 1880 and 1930 allowed the stream to accommodate greater floods, overbank deposition decreased, and further deposits were restricted mostly to the channel belt. The presettlement vegetation was a stable mix of wet meadows and riparian shrubs on the floodplain, a rich aquatic community in the stream, and oak savanna on the valley walls and upland. Disturbance from soil erosion, floodplain erosion and floodplain deposition almost completely replaced both lowland and upland communities with ruderal (disturbed ground) plants, many of them introduced weeds. Regional insect communities were simultaneously affected by changes in land use. The presettlement aquatic beetle fauna was dominated by species of dryopoid beetles that today inhabit only streams of high water quality. Terrestrial beetle taxa included species of undisturbed grasslands and riparian forest. The changes in the landscape resulted in a decrease in the diversity of terrestrial beetle taxa and caused the near total elimination of dryopoid beetles in stream waters. Dominating the historic assemblages are beetles associated with dung, polluted waters and cultivated plants, including host-specific immigrant beetle species that are associated with immigrant plant species.</p></abstract><textClass><keywords scheme="keyword"><list><head>keywords</head><item><term>Euro-American settlement</term></item><item><term>human impact</term></item><item><term>riparian landscape</term></item><item><term>cultural landscape</term></item><item><term>historical evidence</term></item><item><term>floodplain sediments</term></item><item><term>pollen</term></item><item><term>macrofossils</term></item><item><term>insects</term></item><item><term>Iowa</term></item><item><term>midwest.</term></item></list></keywords></textClass></profileDesc><revisionDesc><change when="1993-12">Published</change></revisionDesc></teiHeader></istex:fulltextTEI><json:item><extension>txt</extension><original>false</original><mimetype>text/plain</mimetype><uri>https://api.istex.fr/document/9B6AE279BE1A6C106F2CDBB822870FBB56258972/fulltext/txt</uri></json:item></fulltext><metadata><istex:metadataXml wicri:clean="corpus sage not found" wicri:toSee="no header"><istex:xmlDeclaration>version="1.0" encoding="UTF-8"</istex:xmlDeclaration><istex:docType PUBLIC="-//NLM//DTD Journal Publishing DTD v2.3 20070202//EN" URI="journalpublishing.dtd" name="istex:docType"></istex:docType><istex:document><article article-type="research-article" dtd-version="2.3" xml:lang="EN"><front><journal-meta><journal-id journal-id-type="hwp">sphol</journal-id><journal-id journal-id-type="publisher-id">HOL</journal-id><journal-title>The Holocene</journal-title><issn pub-type="ppub">0959-6836</issn><publisher>
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<publisher-loc>Sage CA: Thousand Oaks, CA</publisher-loc>
</publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.1177/095968369300300403</article-id><article-id pub-id-type="publisher-id">10.1177_095968369300300403</article-id><article-categories><subj-group subj-group-type="heading"><subject>Articles</subject></subj-group></article-categories><title-group><article-title>Impact of Euro-American settlement on a riparian landscape in northeast Iowa, midwestem USA: an integrated approach based on historical evidence, floodplain sediments, fossil pollen, plant macrofossils and insects</article-title></title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Baker</surname><given-names>R.G.</given-names></name><aff>Department of Geology, University of Iowa, Iowa City, Iowa 52242-1379, USA</aff></contrib></contrib-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Schwert</surname><given-names>D.P.</given-names></name><aff>Department of Geosciences, North Dakota State University, Fargo, North Dakota 58105-5517, USA</aff></contrib></contrib-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Bettis</surname><given-names>E.A.</given-names></name><aff>Iowa Department of Natural Resources, Geological Survey Bureau, 123 N Capitol, Iowa City, Iowa 52242, USA</aff></contrib></contrib-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Chumbley</surname><given-names>C.A.</given-names></name><aff>412 Highland Avenue, Iowa City, Iowa 52242, USA</aff></contrib></contrib-group>
<pub-date pub-type="ppub"><month>12</month><year>1993</year></pub-date><volume>3</volume><issue>4</issue><fpage>314</fpage><lpage>323</lpage><abstract><p>European settlement and attendant forest clearance and agricultural activities in northeastern Iowa caused changes in the landscape, vegetation, insect fauna and water quality unequalled in rate and magnitude since the melting of Wisconsinan glaciers. Historical documents show that the upper part of the Roberts Creek drainage basin was settled between AD 1840 and 1856, and the area was under intensive cultivation by 1880. Extensive soil erosion beginning at this time resulted in increased runoff and more frequent flooding; aggradation rates increased by one to two orders of magnitude over those in presettlement times, and the entire floodplain was covered with up to 1 m of sediment. Channel widening between about 1880 and 1930 allowed the stream to accommodate greater floods, overbank deposition decreased, and further deposits were restricted mostly to the channel belt.</p>
<p>The presettlement vegetation was a stable mix of wet meadows and riparian shrubs on the floodplain, a rich aquatic community in the stream, and oak savanna on the valley walls and upland. Disturbance from soil erosion, floodplain erosion and floodplain deposition almost completely replaced both lowland and upland communities with ruderal (disturbed ground) plants, many of them introduced weeds. Regional insect communities were simultaneously affected by changes in land use. The presettlement aquatic beetle fauna was dominated by species of dryopoid beetles that today inhabit only streams of high water quality. Terrestrial beetle taxa included species of undisturbed grasslands and riparian forest. The changes in the landscape resulted in a decrease in the diversity of terrestrial beetle taxa and caused the near total elimination of dryopoid beetles in stream waters. Dominating the historic assemblages are beetles associated with dung, polluted waters and cultivated plants, including host-specific immigrant beetle species that are associated with immigrant plant species.</p></abstract><kwd-group><kwd>Euro-American settlement</kwd>
<kwd>human impact</kwd>
<kwd>riparian landscape</kwd>
<kwd>cultural landscape</kwd>
<kwd>historical evidence</kwd>
<kwd>floodplain sediments</kwd>
<kwd>pollen</kwd>
<kwd>macrofossils</kwd>
<kwd>insects</kwd>
<kwd>Iowa</kwd>
<kwd>midwest.</kwd></kwd-group><custom-meta-wrap><custom-meta xlink:type="simple"><meta-name>sagemeta-type</meta-name><meta-value>Journal Article</meta-value></custom-meta><custom-meta xlink:type="simple"><meta-name>search-text</meta-name><meta-value>314 Impact of Euro-American settlement on a riparian landscape in northeast Iowa, midwestem USA: an integrated approach based on historical evidence, floodplain sediments, fossil pollen, plant macrofossils and insects SAGE Publications, Inc.1993DOI: 10.1177/095968369300300403 R.G. Baker Department of Geology, University of Iowa, Iowa City, Iowa 52242-1379, USA D.P. Schwert Department of Geosciences, North Dakota State University, Fargo, North Dakota 58105-5517, USA E.A. Bettis Iowa Department of Natural Resources, Geological Survey Bureau, 123 N Capitol, Iowa City, Iowa 52242, USA C.A. Chumbley 412 Highland Avenue, Iowa City, Iowa 52242, USA Received 25 August 1992: revised manuscript accepted 21 January 1993 * Iowa Quaternary Studies Contribution No. 53. European settlement and attendant forest clearance and agricultural activities in northeastern Iowa caused changes in the landscape, vegetation, insect fauna and water quality unequalled in rate and magnitude since the melting of Wisconsinan glaciers. Historical documents show that the upper part of the Roberts Creek drainage basin was settled between AD 1840 and 1856, and the area was under intensive cultivation by 1880. Extensive soil erosion beginning at this time resulted in increased runoff and more frequent flooding; aggradation rates increased by one to two orders of magnitude over those in presettlement times, and the entire floodplain was covered with up to 1 m of sediment. Channel widening between about 1880 and 1930 allowed the stream to accommodate greater floods, overbank deposition decreased, and further deposits were restricted mostly to the channel belt. The presettlement vegetation was a stable mix of wet meadows and riparian shrubs on the floodplain, a rich aquatic community in the stream, and oak savanna on the valley walls and upland. Disturbance from soil erosion, floodplain erosion and floodplain deposition almost completely replaced both lowland and upland communities with ruderal (disturbed ground) plants, many of them introduced weeds. Regional insect communities were simultaneously affected by changes in land use. The presettlement aquatic beetle fauna was dominated by species of dryopoid beetles that today inhabit only streams of high water quality. Terrestrial beetle taxa included species of undisturbed grasslands and riparian forest. The changes in the landscape resulted in a decrease in the diversity of terrestrial beetle taxa and caused the near total elimination of dryopoid beetles in stream waters. Dominating the historic assemblages are beetles associated with dung, polluted waters and cultivated plants, including host-specific immigrant beetle species that are associated with immigrant plant species. Euro-American settlement human impact riparian landscape cultural landscape historical evidence floodplain sediments pollen macrofossils insects Iowa midwest. 315 Introduction What impact have land settlement and modern agriculture had on natural landscapes? This question is difficult to answer, because (1) these changes in land use occurred over a century ago in the US, and (2) those remaining natural landscapes in the midwest cannot be tested because they are already affected by such anthropogenic factors as increased runoff and pesticide drift from surrounding areas. However, some of the impacts of agriculture on natural landscapes can be evaluated by comparing presettlement and postsettlement fossil and lithologic records that include the last few hundred years. These records reflect changes in land-use practices and have been used to document some of the resulting impacts on the environment. The purpose of this paper is to illustrate how Euro-American settlement changed the character of the landscape, stream behaviour, vegetation, beetle fauna and water quality in a small northeastern Iowa drainage basin. The record preserved in the Roberts Creek Basin in northeastern Iowa (Figure 1) shows how significant and interrelated the effects of historic land-use changes were on vegetation, slope processes, hydrology, sedimentation and water quality. These changes affected all parts of the landscape to varying degrees, but nowhere was the impact greater than on the floodplain. In order to evaluate the nature of historic floodplain changes, we examined historical documents, Holocene stratigraphy beneath the valley floor, average floodplain aggradation rates, and aspects of the palynology, plant macrofossils, beetles and chemistry of presettlement and historical deposits. We used sites ranging in age from about 3000 BP to the present. The historical deposits are recognized by: (1) sediment stratigraphy, (2) the abundance of plant macrofossils and beetles of introduced species, (3) radiocarbon dates, and (4) the presence of recent artifacts such as barbed wire, glass, bricks and other debris. The historical data reveal the nature and timing of floodplain changes, and the record from about 3000 BP to settlement Figure 1 Location map. Area outlined in Clayton County is the Roberts Creek drainage basin. Uncalibrated radiocarbon ages of sediments at numbered sites are as follows: 1 = modern; 2 = 150 BP; 3 = 1820 BP; 4 = 2850 BP; 5 = 380 BP; 6 = 70 BP; 7a = modern; 7b = 2350 BP; 8 = 1220 BP; 9 = 2900 BP; 10 = modern (see Table 1). time provides baseline information for assessing the changing edaphic and ecologic conditions during this period. The environmental impact of aboriginal agrarian activities during the Neolithic was relatively slight, but it is recognizable in pollen diagrams from Europe, the Middle East and Japan (Tsukada, 1972; Birks et al., 1988). Even in North America, similar small changes from native American agriculture are noticeable (Delcourt et al., 1986; McAndrews, 1988). These effects are generally: (1) slight decreases in pollen of forest taxa, suggesting that forests were cleared for agriculture, (2) slight increases in pollen percentages of crop species that were planted, and (3) increases in pollen of disturbed ground plants, which became established on the newly cleared areas and abandoned fields and gardens. The changes in landscape and vegetation were apparently slight because only small areas were affected and the changes occurred slowly over a relatively long time. In contrast, European settlement in North America caused rapid and consequential changes in the environment over a large region. A rise in Ambrosia (ragweed) pollen percentages of 2-10 times presettlement values is the most widely known marker for the settlement horizon in the eastern and central United States (Webb et al., 1983), and increases in sedimentation also occurred following cultivation (Knox, 1987). However, these studies only hint at the total changes in the ecosystem and landscape as a consequence of settlement. Such changes, as documented in the biotic, sedimentary, pedological and historical record, have rarely, if ever, been studied simultaneously in a drainage basin. Many previous studies in North America that documented impacts of changes in land use have concentrated mainly on lake sediments (Davis, 1973; 1989; Birks et al., 1976; Maher, 1977; Bradbury and Waddington, 1973; Brugham, 1978). For example, Birks et al. (1976) compared the fossil and chemical content of pre- and posthistoric lake sediment in lakes in northwestern Minnesota. At Lake Shagawa, northern Minnesota, Bradbury and Waddington (1973) related changes in lake chemistry and biota to human activities, including mining. Davis (1973), Maher (1977) and Brugham (1978) showed increased sedimentation rates in lakes ranging in size from small ponds to Lake Superior, caused by various human activities. Some recent studies have shown the relationship between human activities and stream behaviour. Knox (1987) related changes in sedimentation in stream valleys in south- western Wisconsin to mining and other human activities, and James (1991) showed changes in stream channel morphology that were related to hydraulic mining in California. The impact of Euro-American settlement on the insect fauna of North America was as profound as that caused by any event in the late Quaternary, including glaciation. Populations of insect species representative of such habitats as forest, native prairie and marshlands were replaced by ruderal species as extensive deforestation, cultivation and drainage of wetlands accompanied the westward expansion of Euro-American settlement (McLeod, 1980; Turnbull, 1980). Associated with settlement was the accidental or intentional introduction of exotic insect species (Lindroth, 1957; Sailer, 1983). For example, of the 1683 immigrant arthropod species reported by Sailer (1983) in the continental United States, 66% originated from the western palaearctic region. The study of beetle remains from archaeological sites has become a well established discipline in Europe (e.g., Buck- land and Kenward, 1973; Osborne, 1974; 1988; Kenward, 1976). In North America, however, such studies are only now being initiated (e.g., Elias, 1986; 1990), and none until now has examined anthropogenic changes of an insect fauna. The discovery of a rich assemblage in northeastern Iowa permits a 316 palaeontological examination of the impact of human activities on the species composition of the regional beetle fauna. Roberts Creek is well suited for studying the effects of agricultural land-use change. Modern vegetation near the study area is mostly pasture on the floodplain and row crops on the uplands, with a few scattered groves of oak. The low permeability of the Ordovician shale that underlies the floodplain has kept the water table at a relatively stable position within the Holocene alluvial fill for the last 12500 years (Bettis, 1984). The creek has meandered across the valley floor throughout the Holocene with little downcutting and only modest aggradation, and numerous beaver-dam ponds, small abandoned channel ponds, and point bars were formed, rapidly buried with sediment, and later exposed by lateral stream migration. These exposures in the creek banks and cores collected from the valley floor are the sources of fossil data. Fossil preservation is excellent, because deposition was rapid and the water table was continuously high. The area sampled is near the headwaters of the basin, guaranteeing that the fossils are of local origin. Over 40 sites spanning the entire Holocene were sampled along the creek. Sixty-one radiocarbon dates, 53 of which were on wood, provide a reliable chronology and indicate that each deposit represents only about 100 to 200 years of accumulation (Chumbley, 1989; Chumbley et al., 1990). Of the 40 sections studied, ten date from the last 3000 years and are the basis of this study. Historical information Conditions at the time of settlement can be approximated from notes recorded during the General Land Office Survey of Wisconsin Territory (1837-1849). At that time, large prairie tracts occupied most upland and gently sloping areas, while timber was restricted to a narrow belt along the Roberts Creek channel. Human impacts were minimal; a military road traversed the northeastern part of the basin, three small fields were present in the basin's northeastern uplands, and there was a single field on the divide near the junction of Deer and Roberts creeks, within the reach of the valley where our study sites are located. The 1838 census of Wisconsin Territory supports this image of few inhabitants; a population of 274 is recorded for Clayton County, most of whom lived by the Mississippi River. Soon thereafter Euro-American settlement increased markedly. The population of Clayton County was 500 in 1840 and 1000 in 1850. By 1856 more than 1000 people, mostly farmers, lived in Roberts Creek basin alone (Iowa State Census, 1856), and by 1880 a large percentage of upland and broad valley tracts in the basin was in wheat, maize and hay (Benton and Gray, 1925). Knox (1987) used historical records along with a variety of sedimentological tracers derived from mining operations to evaluate the timing of floodplain aggradation during the historical period in southwest Wisconsin. He concluded that tributary valleys aggraded primarily between about 1890 and 1930. After that time the meander belt expanded, and sedimentation decreased sharply outside the meander belt. Although we are not able to date precisely the period of historical sedimentation because these age tracers were not available in the Roberts Creek drainage basin, a similar chronology is likely. One line of evidence that supports the idea that historical sedimentation was nearly completed by the 1920s in the Roberts Creek study area is that soils mapped in this part of the valley in the 1920s were noted to be 'well above overflow' (Benton and Gray, 1925). Methods Deposits exposed in stream banks along Roberts Creek were measured and described using standard procedures and nomenclature (Soil Survey Staff, 1975). Deposits were also examined in 7.6-cm-diameter cores taken with a drill rig. Coring transects and bank exposures were used to determine the thickness of historical alluvium across the valley floor. Samples for radiocarbon dating were collected from stream banks and cores. All samples were analysed by Beta-Analytic, Incorporated, and the ages reported are uncorrected except as noted (Table 1). Samples for pollen, macrofossils and insects were dug by hand from cut banks along Roberts Table 1 Radiocarbon ages of samples reported in this study. Site numbers refer to locations on Figure 1 Note: * p = pollen, m = macrofossils, b = beetles. 317 Figure 2 Pollen diagram constructed from six sites showing ten selected pollen taxa. Creek. Approximately 300 cm3 of matrix were collected for pollen and macrofossil analysis and about 20 kg for insect analysis at each site. Pollen samples were processed following Flegri et al. (1989) using KOH, HCI, acetolysis and HF. In addition, the sediment was sieved through a 7 Rm screen (Cwynar et al., 1979), treated with 10% sodium hypochlorite solution and floated using ZnCI (Chumbley, 1989). Pollen was mounted in silicone fluid, and at least 300 pollen grains were counted in each sample. Plant macrofossils were sieved using 0.5- and 0.105-mm screens, and wet residues were hand picked. Samples were stored in glycerin with a pinch of phenol as a preservative. Pollen and macrofossils were identified using reference collections at the University of Iowa Geology Department and are preserved in the repository there. Plant nomenclature follows Gleason and Cronquist (1963). Not every sample was analysed for all biotic elements. Ten sites have macrofossil analyses, whereas pollen and insects were analysed from six sites. The uppermost sample on the pollen diagram (Figure 2) is from historical sediments (site 6 on Figure 1) of about 1880 BP; the uppermost macrofossil samples are from modern abandoned channel sediments. Bulk samples of the sediment were processed for fossil beetles according to procedures described in Ashworth (1979). The beetle remains (mainly heads, pronota and elytra) are disarticulated but otherwise well preserved. They are reposited on microslides and in vials at the Quaternary Entomology Laboratory, North Dakota State University, Fargo, North Dakota. Grain size composition of the deposits was determined using the pipette method (Walter et al., 1978). Organic carbon, total nitrogen and total phosphorous contents were determined at the Iowa State University Soil Survey Laboratory using standard methods (Dick and Taba- tabai, 1977; Yeomans and Bremner, 1991). Results and discussion Characteristics of historical alluvium Historical alluvium in Roberts Creek basin is similar to that found in other parts of the upper Midwest (Magilligan, 1985; Bettis and Littke, 1987; W.C. Johnson, 1987; Knox, 1987; Bettis, 1990). It consists primarily of very dark greyish brown (10YR3/2) to dark brown (10YR4/3) planar bedded silt loam and loam resting abruptly on the very dark grey (10YR3/1) to black (10YR2/1), a horizon of the presettlement surface soil (usually a mollisol). Bedding is usually absent in the upper few decimetres of the postsettlement deposits because sedimentation was slow or intermittent, allowing sufficient time for bioturbation and other pedogenic processes to destroy former bedding structures. The thickness of historical alluvium varies across the valley floor. Within the modern channel belt, the thickness of the fine grained increment of the historical alluvium is extremely variable, ranging from < 10 cm to 2 m. Outside the channel belt its thickness averages 1 m where it buries Holocene alluvium younger than about 3500 BP and 44 cm where it buries older Holocene alluvium. The surface of these buried deposits ranges from 0.5-1.5 and 1.7-2.4 m above the adjacent channel bed, respectively. Low terraces underlain by alluvium older than about 8000 BP are usually elevated more than 2.5 m above the adjacent channel bed and have little or nor cap of historical alluvium. Knox (1987) found similar relationships among thickness of historical alluvium, age of the underlying presettlement deposits, and relative elevation of the presettlement surface in the Driftless Area of Wisconsin. Historical alluvium is also found at the base of valley wall slopes where it varies from a few cm to 50 cm in thickness. In a few places 1-2 m of historical alluvium were recorded beneath small alluvial fans emanating from steep, healed gullies on valley slopes. Calculation of average sedimentation rates (from observations at more than 50 sites) using an age of 150 years for the base of the historical alluvium, and radiocarbon ages for late Holocene and early to middle Holocene-age alluvium indicates that aggradation increased from presettlement rates of 0.028-0.13 cm year to an average of 0.7 cm year in the historic period. The presettlement values are comparable to those obtained by Knox (1987) in streams of similar size in Wisconsin's Driftless Area, but the historic values from Roberts Creek are higher than those from the Driftless Area. If most of the historical alluvium accumulated in the 40 years between AD 1890 and 1930, as suggested by historical records, then the historic sedimentation rate is even higher, about 2.6 cm year-1. The organic carbon content of historical alluvium is slightly lower than that of the upper, humus-rich A horizon of the 318 buried presettlement soil, but significantly higher than that of the presettlement alluvium beneath the A horizon. These differences probably reflect the origin of a significant part of the historical alluvium from erosion of the upper, organic-rich part of soil profiles in the watershed. The contrast between the organic carbon content of historical and presettlement alluvium is not as great for deposits dating from 3500 BP or later (the presettlement floodplain) as it is for older alluvial deposits (presettlement low terraces). Total nitrogen relationships parallel those of organic carbon. Total phosphorus content is much lower in historical alluvium than in late Holocene alluvium, but similar to that of early and middle Holocene alluvium and the upper horizons of loess-derived upland and valley slope soils. The chemical properties of historical alluvium are consistent with an interpretation that the unit was derived primarily from erosion of the upper solum (A, E and upper B horizons) of prairie/forest transition (Mollic Hapludalfs) and forest (Typic Hapludalfs) soils in the Roberts Creek drainage basin. Three phases of change in historical valley floor hydrology and sedimentation are evident. The first occurred during the early settlement period and involved land clearing and initial cultivation. The amount of land in cultivation was small at the beginning of this period, but increased dramatically in the 1850s. Initially the deep, organic-rich prairie and prairie- forest transitional soils of the upper part of Roberts Creek basin continued to provide relatively good infiltration, so that runoff remained relatively low. Experimental studies indicate that the original vegetation and porous, humus-rich presettlement top soil were extremely effective in retarding surface runoff and sediment yield (Sartz, 1975; 1976). However, after several years of cultivation with poor conservation practices, the infiltration capacity of the soils in the basin decreased, and the increased runoff began to reach the channel network. In the last decade or two of the nineteenth century the second phase began, as flood peaks and sedimentation increased significantly because poor conservation practices intensified soil erosion and augmented runoff. Frequent flooding and relatively rapid floodplain aggradation continued until sometime in the 1920s or 1930s, then began to decrease as the channel adjusted to the changed hydrologic conditions by widening. At that time the meander belt expanded, less of the valley floor was flooded, and floodplain sedimentation decreased. During the final stage, runoff and sediment delivery to the valley decreased as a result of the adoption of better soil and water conservation practices. This final phase of valley floor changes has been characterized by decreased valley floor sedimentation, lower peak flood height, and maintenance of a relatively wide channel. Plants Pollen analysis of the cut bank and core sediments shows that the presettlement vegetation pattern was established in the area about 3000 BP (Figure 2; see also Chumbley et at., 1990). Land survey records from the 1830s and 1840s (Chumbley, 1988; unpublished data) indicate that oak savanna occupied much of the Roberts Creek basin. Prior to settlement the major pollen types present were Quercus (15-20% ), Salix (2-20% ), Poaceae (20-35% ), Asteraceae excluding Ambrosia (10-15%) and Cyperaceae (20-25%). Pollen of aquatic plants, especially Myriophyllum, was also relatively common. This pollen rain supports the contention that the upland area was an oak savanna and the floodplain supported willows along with other wetland and aquatic plants. Plant macrofossil analyses of these deposits (Figures 3 and 4) support the idea that a rich mix of aquatic, wetland, wet prairie and riparian elements was present on the floodplain. Figure 3 Summary of changes in plant macrofossils arranged in four ecological groups: (1) aquatic, (2) prairie, (3) riparian and (4) ruderal plants. 3A = plotted by number of taxa; 3B = plotted by number of specimens per litre. Prehistoric bar is mean of seven sites (2, 3, 4, 5, 7a, 8 and 9 on Figure 1); historic bar represents one site (6 on Figure 1), and modern bar is mean of two sites (1 and 7 on Figure 1). The major tree during presettlement time is Salix, with single occurrences of Ulmus americana, Tilia americana and Quercus. Forest herbs are restricted to Ranunculus septentrionalis, which can grow in riparian forest environments. Shrubs are represented by Cornus amomum subspecies obliqua, Cornus sp. and Rubus, all floodplain or edge species. Disturbed ground plants are sparingly present, but most cannot be identified to species. These include Amaranthus, Chenopo- dium and Oxalis. A variety of prairie indicator species occurs in presettlement sites; among the more regularly occurring are Amorpha canescens, Hypoxis hirsuta, Monarda fistulosa, Pycnanthemum virginianum, Ratibida pinnata, Rudbeckia hirta and Zizia aurea. Nine species of aquatic plants also grew in the stream or in floodplain ponds, but their occurrence is sporadic. Macrofossils of the historical period (Figure 3) were found in site 6 (Figure 1). This site is dated by a piece of barbed wire, which was of the type called 'Glidden's Barb, One- strand Variation' (written communication from A.L. Fisk to D.P. Schwert, 12 August 1989). The patent for this make was issued in 1874, and the site is estimated to date from about 1880. 319 Figure 4 Plant macrofossil diagram of ruderal taxa at Roberts Creek during the last 3000 BP, showing the increase in abundance of most taxa following settlement. Pollen percentages of Ambrosia and Poaceae rise sharply in the historical sample to about 25% and 40% respectively, whereas those of Quercus, total arboreal pollen, Asteraceae and Cyperaceae decline to 10%, 20%, <5% and <5% respectively. The rise in Ambrosia and the decline in Quercus and other trees are widespread in the eastern and midwestern United States and represent land clearance, but effects on other taxa were not known. The diversity and abundance of plant macrofossils of prairie, aquatic and wetland taxa decreased after settlement occurred (Figures 3 and 4). The number both of taxa and of specimens of aquatic plants decreased from prehistoric (mean of seven samples dated between 3000 BP ant - 150 BP) to historic time (one sample from -AD 1880) and apparently recovered slightly in modern time (two samples). Only Pota- mogeton has been seen in the modern stream, though Chara oospores are present in the modern samples. Prairie and riparian taxa and specimens decrease markedly between prehistoric and historic time, and the decrease continues to the modern samples. Only rare Salix trees are present along the modern stream, and prairie elements are completely absent from cultivated areas, and rare to absent in pastures on the floodplain. Ruderal annual plants are present in low numbers and diversity prior to settlement, but their diversity triples by -AD 1880, and the number of specimens increases by about two orders of magnitude. The diversity remains high in the modern samples, but the number of specimens drops to about twice presettlement values. These 'weeds' included the introduced species, Pastinaca sativa, Polygonum aviculare, Polygonum hydropiper, Poly- gonum convolvulus, Setaria glauca, Setaria viridis and Taraxa- cum officinale. Native ruderal genera present in small numbers earlier in the Holocene are Chenopodium, Echino- chloa and Amaranthus sp. Euphorbia maculata appeared only in historical sediment, and Polygonum pensylvanicum occurred sparsely in mid-Holocene time, and increased following cultivation. The plant record indicates that major changes in vegetation occurred following forest clearance and cultivation. The details of the timing of these changes have yet to be established, but by -AD 1880 most of the changes had occurred. In the uplands, oaks in the savanna apparently had been reduced substantially, and prairies had largely been ploughed under. On the floodplain, native wetland, riparian and prairie communities had been almost completely replaced by crops. Ruderal elements were dominant in the fossil assemblage. By modern time, the prairie and riparian communities had further declined, and aquatic communities in the stream had showed little recovery. Ruderal annuals were considerably less abundant (though diversity remained high). The correlation of a maximum in ruderal plants with the time of maximum flooding is probably not coincidental. The most abundant niche along the stream for disturbed ground plants would be the bare soil exposed by both erosion and deposition during floods. Ruderal species were at their maximum during this time. The decrease in numbers of ruderal species in modern samples may be explained by: (1) the greater stability and lesser flooding that accompanied enlargement of the meander belt, decreasing the area available for colonization by these plants, and; (2) the use of herbicides in the area in recent decades. Insects Twenty one families of beetles are represented in the pre- and post-settlement assemblages (Schwert, in prep.). In addition to beetles, the remains of molluscs, ostracods, spiders, orbatid mites, and other orders of insects are present. Pre-settlement species Samples from the presettlement sites contain remarkably diverse assemblages of ground beetles (Carabidae). Most of the species represented are associated with water-marginal or marshland environments. Several, however, including Cyclo- trachelus s. sodalis LeC., C. seximpressus LeC., Poecilus lucublandus (Say), and Amara angustata (Say), are inhabitants of open grasslands (Lindroth, 1966; 1968; Freitag, 1969). Others, including Scaphinotus elevatus (Fab.) and Pterostichus stygicus (Say), are woodland species (Lindroth, 320 1961; 1966). Additional upland taxa include Hyperaspis brun- nescens Dobz., an apparently rare ladybird (Coccinellidae) species known today only from Iowa and Illinois (Gordon, 1985), and numerous remains of the scarabaeid provisionally identified as Macrodactylus subspinosus (Fab.), the common 'rose chafer'. Dryopoid beetles, particularly elmids, are the numerically largest faunal component of the presettlement assemblages, representing approximately two-thirds of all beetle remains. Five species of elmids (Dubiraphia cf. vittata [Melsh.], Macro- nychus glabratus Say, Microcylloepus pusillus [LeC.], Optio- servus fastiditus [LeC.] and Stenelmis cf. crenata [Say]) and one species of dryopid (Helichus striatus LeC.) are represented. Dryopoid faunas of this diversity and richness exist today only in association with the bedrock- or gravel-bedded riffle zones of streams of exceptionally high water quality (Brown, 1976; Hilsenoff, 1977). Numerous water-marginal and marsh-associated taxa are present in the remaining component of the presettlement beetle assemblages. Saprophagous species, however, are poorly represented; the occurrences of the dung-associated scarabaeid Onthophagus hecate (Panz.) might have been in association with occasional visits to the stream by large herbivores such as bison. Together, the insect assemblages show that a mixture of open grasslands and riparian woodlands characterized the drainage basin of presettlement Roberts Creek. The stream itself was of trout-stream water quality, with gravel substrate and with alternating riffles and pools bordered by muddy banks and zones of marsh-associated plants. Postsettlement species Of the 12 species of carabids collectively represented in the postsettlement samples, all but one (Cyclotrachelus sodalis ) are associated with marsh or water-marginal habitats. No woodland-associated carabids are present, although two gen- eralist taxa of bark beetles (Scolytidae) occur. Upland elements of the postsettlement assemblages are dominated instead by scarabaeids (Scarabaeidae) and weevils (Curculionidae). Of the six species of the scarabaeid dung beetle Aphodius definitively or provisionally identified, all are today regularly associated with cattle dung. Two, A distinctus (Miiller) and A. granarius (L.), represent introductions from Europe (Table 2), the latter apparently during the seventeenth century aboard ships carrying cattle from England (Sailer, 1983; Ratcliffe, 1991). At least six species of the large postsettlement weevil assemblage represent immigrant species that themselves are associated with immigrant host plants (Table 2). Nearctic weevil species (and their associated host plants) include Hypera cf. compta Say (Polygonum coccineum), Nedyus flavicaudis (Boh.) (Urtica sp.), Listronotus cf. appendiculatus (Boh.) (Sagittaria spp.), and the billbug weevils Sphenophorus parvulus Gyll. and S. minimus Hart. (serious pests of turf- forming grasses) (Puttler et al., 1973; Vaurie, 1983; Johnson- Cicalese et al., 1990; R.S. Anderson, pers. comm., 1990). Other anthrophilic taxa represented in the postsettlement assemblages include the palaearctic chrysomelid Phyllotreta striolata (Fab.) (a widespread pest, particularly of cruciferous vegetables) and the nearctic nitidulid Glischrochilus quad- risignatus Say (a pest of fruit and maize) (Smith, 1985; Bousquet, 1990). Fossils of the cryptophagid Atomaria ephip- piata Zimm. and a cucujid provisionally identified as Crypto- lestes ferrugineus (Steph.) are present; these species commonly occur today in association with stored grains, the latter being a serious pest, particularly of wheat (Bousquet, 1990). Whereas the remains of dryopoid water beetles over~ whelmingly dominated the presettlement assemblages, they are nearly absent from postsettlement samples (Figure 5). Replacing elmids as the most abundant water beetle taxon is the haliplid Peltodytes edentulus LeC., one of the few species of aquatic beetles that appears to thrive in shallow, eutrophic and polluted pools and streams. Interpretation of the insect evidence Records compiled from museum and literature sources indicate that all of the beetle species identified from pre- and postsettlement samples could potentially occur within the region of Roberts Creek today. The postsettlement transformation of the landscape by cultivation appears to have profoundly affected the species diversity of the carabid and scarabaeid faunas (Figure 6). In this analysis, the pre- and postsettlement representations of these families are standardized to species per kilogram of sample sediment. Carabid diversity markedly decreases, with upland species in particular being no longer well represented in postsettlement Table 2 Exotic species of Coleoptera represented as fossils in samples of postsettlement age from the Roberts Creek basin, with notes on their habitats, host plants, or food sources Note: *Host plants of palearctic origin (Gleason and Cronquist, 1963). 321 Figure 5 Changes in average numbers of carabid and dung-associated scarabaeid species represented per kilogram of sediment in pre- and postsettlement deposits of Roberts Creek. samples; the detrimental impact on carabid populations by agricultural manipulation of modern landscapes has been well documented (e.g., Luff and Rushton, 1989; Weiss et at., 1990). The diversity of dung-associated scarabaeids, however, sharply increases upon settlement, as cattle and other large herbivores are introduced to graze proximal to Roberts Creek. Sedimentation and eutrophication associated with agricultural transformation of the landscape likewise made the waters of Roberts Creek inhospitable to most species of aquatic Coleoptera. Although we commonly encountered live elmids in abundance clinging to stones in riffle areas of the nearby Turkey River, dryopoid beetles today rarely occur in the waters of Roberts Creek (Kennedy and Miller, 1990). A thick layer of sediment of postsettlement age now blankets what was once the gravel or bedrock bottom of Roberts Creek, effectively eliminating drypoid habitat. As might be predicted, water-marginal beetles, inhabiting zones that are directly affected by neither cultivation nor eutrophication, represent the group least affected by Euro-American settlement. The faunal record of changes marking the transformation of the Roberts Creek basin to an agricultural landscape bear remarkable similarities to fossil insect records of the English Midlands as observed by Osborne (1974; 1988). Forests that had once characterized the region proximal to the River Avon in Warwickshire were by late Bronze Age (ca. 2900 BP) largely replaced by grasslands occupied by large grazing herbivores such as cattle and sheep. As forest clearing and ploughing of the landscape progressed, soil erosion led to increased sedimentation and to the elimination of the rich elmid populations of the River Avon. Conclusions The spread of agriculture in northeastern Iowa had several impacts on the local ecosystem and landscape in the time following settlement. (1) During the land clearance phase, stable vegetation types were replaced by disturbed ground plants, and soils were degraded by cultivation and poor conservation prac- Figure 6 Changes in total numbers of elmid elytra represented per kilogram of sediment in pre- and postsettlement deposits of Roberts Creek. Age of deposits is given in italics. tices. This disturbance apparently was at its peak between -AD 1880 and 1930. (2) The loss of stable vegetation cover and infiltration capacity caused by soil erosion resulted in increased runoff, thereby increasing flood frequency and magnitude for several decades after land clearance. (3) These changes greatly accelerated hill slope erosion, removing the A horizons of upland soils and depleting their tilth and fertility. (4) Increased sediment delivery to the valley network resulted in the accumulation of up to 2 m of sediment derived from uplands and slopes in the channel belt and between 0.4 and 1.0 m on the floodplain between -AD 1890 and 1920. This new alluvium was fertile, but the rapid sedimentation rate (approximately 5-25 times the presettlement rate) across much of the valley floor resulted in edaphic conditions that favoured colonization by disturbed ground plants. (5) Since -AD 1920, channel widening has decreased flooding and floodplain aggradation rates. (6) Diversity of native plants has decreased, and native plant communities have been lost to aggressive introduced species that are temporary colonizers of disturbed ground. (7) Water quality has been severely degraded from a clear, cold-water trout stream to a polluted, silt-laden creek. (8) Changes in beetle populations show that upland carabids declined and taxa associated with crop plants and cattle dung increased. Acknowledgements This research was supported by NSF Grants ATM-88-06482 to R.G. Baker and ATM-88-0571 to D.P. Schwert. For their assistance in identification of beetle remains, we are grateful to the staff of the Coleoptera Division of the Biosystematics Research Centre, Agriculture Canada, to H.P. Brown of the University of Oklahoma (Dryopidae and Elmidae), to R.S. Anderson of the National Museum of Canada (Curculionidae) and to R.D. Gordon of the Systematic Entomology Laboratory, USDA (Scarabaeidae). For their help in both field and laboratory analyses, we thank Joseph Krieg, Kevin Krogstad, Sally Domke and Cynthia Jensen. References Ashworth, A.C. 1979: A method of recovering fossil insect remains from clays, peats, and silts. In Erwin, T.L., Ball, G.E. and Whitehead, D.R. editors, Carabid beetles, their evolution, natural history, and classification, The Hague: W. Junk, 406. 322 Benton, T.H. and Gray, A.L. 1925: Soil survey of Clayton County, Iowa . Washington, D.C.: U.S. Dept. of Agriculture, Bureau of Chemistry and Soils. Bettis III, E.A. 1984: Preliminary investigations of the stratigraphy and chronology of northeastern Iowa alluvium and its archaeological significance with special reference to the Turkey River Basin. Report submitted to the Iowa State Historical Department, Division of Historic Preservation, Des Moines. — 1990: Holocene Alluvial Stratigraphy and Selected Aspects of the Quaternary History of Western Iowa. Guidebook for the 37th Midwest Friends of the Pleistocene Field Conference. Bettis III, E.A. and Littke, J.P. 1987: Holocene alluvial stratigraphy and landscape development in Soap Creek Watershed Appanoose, Davis, Monroe, and Wapello counties, Iowa . Iowa Department of Natural Resources, Geological Survey Bureau. Open File Report 87-2. Iowa City. Birks, H.H., Birks, H.J.B., Kaland, P.E. and Moe, D. 1988: The cultural landscape - past, present and future. Cambridge: Cambridge University Press. Birks, H.H., Whiteside, M.C., Stark, D.M., and Bright, R.C. 1976: Recent paleolimnology of three lakes in northwestern Minnesota . Quaternary Research 6, 249-72. Blatchley, W.S. and Leng, C.W. 1916: Rhynchophora or weevils of north eastern America. Indianapolis: Nature Publications. Bousquet ,Y. 1990: Beetles associated with stored products in Canada: an identification guide. Ottawa, Canada: Agriculture Canada Research Branch Publication 1837. Bradbury, J.P. and Waddington, J.C.B. 1973: The impact of European settlement on Shagawa Lake, northeastern Minnesota, U.S.A. In Birks, H.J.B. and West, R.G., editors, Quaternary Plant Ecology, Oxford: Blackwell, 289-317. Brown, H.P. 1976: Aquatic dryopoid beetles (Coleoptera) of the United States . Cincinnati, Ohio, USA: US Environmental Protection Agency Water Pollution Control Research Series 18050-ELD04/72. Brugham, R.B. 1978: Human disturbance and the historical development of Linsley Pond. Ecology 59, 19-36. Buckland, P.C. and Kenward, H.K. 1973: Thorne Moor: a palaeo-ecological study of a Bronze Age site. Nature 241, 405-406. Chumbley, C.A. 1988: Late glacial and Holocene vegetation. In Green, W., editor, Archaeological and paleoenvironmental studies in the Turkey River Valley, northeastern Iowa, Report to the Iowa State Preserves Board, 74-109. — 1989: Late-glacial and Holocene vegetation of the Roberts Creek Basin, northeast Iowa. University of Iowa Ph.D. Dissertation, 154 pp. Chumbley, C.A., Baker, R.G. and Bettis III, E.A. 1990: Midwestern Holocene paleoenvironments revealed by floodplain deposits in northeastern Iowa. Science 249, 272-74. Cwynar, L.C., Burden, E. and McAndrews, J.H. 1979: An inexpensive method for concentrating pollen and spores from fine grained sediments. Canadian Journal of Earth Sciences 16, 1115-20. Davis, M.B. 1973: Pollen evidence of changing land use around the shores of Lake Washington. Northwest Science 47, 133-48. — 1989: Retrospective studies. In Likens, G.E., editor, Long-term studies in ecology, approaches and alternatives, New York: Springer-Verlag , 71-89. Delcourt, P.A., Delcourt, H.R., Cridlebaugh, P.A. and Chapman, J. 1986: Holocene ethnobotanical and paleoecological record of human impact on vegetation in the Little Tennessee River Valley, Tennessee . Quaternary Research 25, 330-49. Dick, W. and Tabatabai, M.A. 1977: An alkaline oxidation method for the determination of total phosphorous in soils. Soil Science Society of America Proceedings 41, 511-14. Elias, S.A. 1986: Fossil insect evidence for late Pleistocene paleoenvironments of the Lamb Spring site, Colorado. Geoarchaeology 1, 381-87. — 1990: The timing and intensity of environmental changes during the Paleoindian period in western North America: evidence from the insect fossil record: In Agenbroad, L., Mead, J. and Nelson, L., editors, Megafauna and man, Flagstaff: Northern Arizona University Press, 11-14. Faegri, K., Kaland, P.E. and Krzywinski, K. 1989: Textbook of Pollen Analysis. New York : John Wiley and Sons. Freitag, R. 1969: A revision of the species of the genus Evarthrus LeConte (Coleoptera: Carabidae). Quaestiones Entomologicae 5, 89-212. General Land Office Survey of Wisconsin Territory 1837-1849. Gleason, H.A. and Cronquist , A. 1963: Manual of vascular plants of northeastern United States and adjacent Canada . New York: D. Van Nostrand. Godfrey, L.D. and Yeargan, K.V. 1989: Effects of clover root curculio, alfalfa weevil (Coleoptera: Curculionidae), and soil-borne fungi on alfalfa stand density and longevity in Kentucky. Journal of Economic Entomology 82, 1749-56. Gordon, R.D. 1985: The Coccinellidae (Coleoptera) of America north of Mexico . Journal of the New York Entomological Society 93, 1-912. Harde, K.W. 1981: A field guide in colour to beetles. London: Octopus Books. Hisenoff, W.L. 1977: Use of arthropods to evaluate water quality of streams . Wisconsin Department of Natural Resources (Madison) Technical Bulletin No. 100, 15 pp. Hoffman, A. 1954: Faune de France. 59. Coléoptères curculiondes (Deuxieme Partie). Paris: Federation Francaise des Sociétés de Sciences Naturelles. Iowa State Census 1856. James, L.A. 1991: Incision and morphologic evolution of an alluvial channel recovering from hydraulic mining sediment. Geological Society of America Bulletin 103, 723-36. Johnson, J.P. 1944: The imported long-horned weevil Calymycterus setarius Roelofs. Bulletin of the Connecticut Agricultural Experiment Station 19, 121-42. Johnson, W.C., editor, 1987: Quaternary environments of Kansas. Kansas Geological Survey, Guidebook Series 5, Lawrence . Johnson-Cicalese, J.M., Wolfe, G.W. and Funk, C.R. 1990: Biology, distribution, and taxonomy of billbug turf pests (Coleoptera: Curculionidae). Environmental Entomology 19, 1037-46. Kennedy, J.O. and Miller III, J.G. 1990: A survey of the benthic macroinvertebrates of the Big Spring Basin, Iowa. Journal of the Iowa Academy of Sciences 97, 46-54. Kenward, H.K. 1976: Reconstructing ancient ecological conditions from insect remains; some problems and an experimental approach. Ecological Entomology 1, 7-17. Knox, J.C. 1987: Historical valley floor sedimentation in the Upper Mississippi Valley. Annals of the Association of American Geographers 77, 224-44. Lindroth, C.H. 1957: The faunal connections between Europe and North America . New York: John Wiley and Sons . — 1961: The ground-beetles (Carabidae, excl. Cicindelinae) of Canada and Alaska (2). Opuscula Entomologica Supplementum 20, 1-200. — 1966: The ground-beetles (Carabidae, excl. Cicindelinae) of Canada and Alaska (4). Opuscula Entomologica Supplementum 29, 409-648. — 1968: The ground-beetles (Carabidae, excl. Cicindelinae) of Canada and Alaska (5). Opuscula Entomologica Supplementum 33, 649-944. Litsinger, J.A. and Apple, J.W. 1984: Summer diapause of the clover leaf weevil, Hypera punctata and lesser clover leaf weevil, Hypera nigrirostris, in Wisconsin. Great Lakes Entomologist 17, 83-86. Luff, M.L. and Rushton, S.P. 1989: The ground beetle and spider fauna of managed and unimproved upland pasture. Agriculture Ecosystems and Environments 25, 195-205. Magilligan, F.J. 1985: Historical floodplain sedimentation in the Galena River basin, Wisconsin and Illinois. Annals of the Association of American Geographers 75, 583-94. Maher, L.J., Jr. 1977: Palynological studies in the western arm of Lake Superior. Quaternary Research 7, 14-44. McAndrews, J.H. 1988: Human disturbance of North American forests and grasslands: The fossil pollen record. In Huntley, B. and Webb III, T., editors, Vegetation history, Dortdrecht: Kluwer, 673-97. McAvoy, T.J., Kok, L.T., and Trimble, J.T. 1983: Biological studies of Ceutorhynchus punctiger (Coleoptera: Curculionidae) on dandelion in Virginia. Annals of the Entomological Society of America 76, 671-74. 323 McLeod, J.M. 1980: Forests, disturbances, and insects. The Canadian Entomologist 112, 1185-92. Moore, I. 1979: Platystethus cornutus Gravenhorst reported from the United States is P. degener Mulsant and Rey (Coleoptera: Staphylinidae). Coleopterists Bulletin 33, 32. Moore, I. and Legner, E.F. 1971: A review of the nearctic species of Platystethus (Coleoptera: Staphylinidae). Pan-Pacific Entomologist 47,260-64. Osborne, P.J. 1974: An insect assemblage of early Flandrian age from Lea Marston, Warwickshire, and its bearing on the contemporary climate and ecology. Quaternary Research 4, 471-86. — 1988: A late Bronze Age insect fauna from the River Avon, Warwickshire, England: its implications for the terrestrial and fluvial environment and for climate. Journal of Archaeological Science 15, 715-27. Puttler, B., Thewke, S.E. and Warner, R.E. 1973: Bionomics of three nearctic species, one new, of Hypera (Coleoptera: Curculionidae), and their parasites. Annals of the Entomological Society of America 66, 1299-1306. Ratcliffe, B.C. 1991: The scarab beetles of Nebraska. Bulletin Nebraska State Museum 12, 1-333. Sailer, R.I. 1983: History of insect introductions. In Wilson, C.L. and Graham, C.L., editors, Exotic plant pest and North American agriculture , New York: Academic Press, 15-38. Sartz, R.S. 1975: Controlling runoff in the Driftless Area. Journal of Soil and Water Conservation 30, 92-93. — 1976: Sediment yield from steep lands in the Driftless Area . In Proceedings of the Third Federal Inter-Agency Sedimentation Conference, Washington, D.C.: U.S. Government Printing Office, I-123-31. Smith, E.H. 1985: Revision of the genus Phyllotera Chevrolat of America north of Mexico. Part I. The maculate species (Coleoptera: Chrysomelidae, Alticinae). Fieldiana (Zoology, New Series) 28, 1-168. Soil Survey Staff 1975: Soil Taxonomy. Washington, D.C.: U.S. Department of Agriculture Handbook 436. Tsukada, M. 1972: The history of Lake Nojiri, Japan. Connecticut Academy of Arts and Sciences Transactions 44, 339-65. Turnbull, A.L. 1980: Man and insects: the influence of human settlement on the insect fauna of Canada. The Canadian Entomologist 112, 1177-84. Vaurie, P. 1983: A catalog of the Coleoptera of America north of Mexico. Family: Curculionidae. Subfamily: Rhynchophorinae. Washington, D.C.: U.S. Department of Agriculture Handbook 529-143a. Walter, N.F., Hallberg, G.R. and Fenton, T.E. 1978: Particle-size analysis by the Iowa State University Soil Survey Laboratory. In Hallberg, G.R., editor, Standard Procedures for Evaluation of Quaternary Materials in Iowa, Iowa City: Iowa Geological Survey, Technical Information Series No. 8, 61-74. WebbIII, T., Cushing, E.J. and Wright, H.E., Jr. 1983: Holocene changes in vegetation of the Midwest . In Wright, H.E., Jr., editor, Late Quaternary environments of the United States, Volume 2, The Holocene , Minneapolis: University of Minnesota Press, 142-65. Weiss, M.J., Balsbaugh, E.U., Jr., French, E.W. and Hoag, B.K. 1990: Influence of tillage management and cropping system on ground beetle (Coleoptera: Carabidae) fauna in the northern Great Plains. Environmental Entomology 19, 1388-91. Yeomans, J.C. and Bremner, J.C. 1991: Carbon and nitrogen analysis of soils by automated combustion techniques. Communications in Soil Science and Plant Analysis 22, 843-850.</meta-value></custom-meta></custom-meta-wrap></article-meta></front><back><ref-list>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Ashworth, A.C.</surname></name>
<year>1979</year>: <source>A method of recovering fossil insect remains from clays, peats, and silts</source>. In <name name-style="western"><surname>Erwin, T.L.</surname></name>, <name name-style="western"><surname>Ball, G.E.</surname></name> and <name name-style="western"><surname>Whitehead, D.R.</surname></name> editors, <source>Carabid beetles, their evolution, natural history, and classification</source>, <publisher-loc>The Hague</publisher-loc>: <publisher-name>W. Junk</publisher-name>, <fpage>406</fpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Benton, T.H.</surname></name> and <name name-style="western"><surname>Gray, A.L.</surname></name>
<year>1925</year>: <source>Soil survey of Clayton County</source>, <publisher-loc>Iowa</publisher-loc> . <publisher-loc>Washington, D.C.</publisher-loc>: <publisher-name>U.S. Dept. of Agriculture</publisher-name>, Bureau of Chemistry and Soils.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Bettis III, E.A.</surname></name>
<year>1984</year>: <source>Preliminary investigations of the stratigraphy and chronology of northeastern Iowa alluvium and its archaeological significance with special reference to the Turkey River Basin</source>. Report submitted to <publisher-name>the Iowa State Historical Department, Division of Historic Preservation</publisher-name>, <publisher-loc>Des Moines</publisher-loc>.</citation>
</ref>
<ref>
<citation citation-type="confproc" xlink:type="simple">— <conf-date>1990</conf-date>: <article-title>Holocene Alluvial Stratigraphy and Selected Aspects of the Quaternary History of Western Iowa</article-title>. <conf-name>Guidebook for the 37th Midwest Friends of the Pleistocene Field Conference</conf-name>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Bettis III, E.A.</surname></name> and <name name-style="western"><surname>Littke, J.P.</surname></name>
<year>1987</year>: <source>Holocene alluvial stratigraphy and landscape development in Soap Creek Watershed Appanoose, Davis, Monroe, and Wapello counties, Iowa</source> . <publisher-name>Iowa Department of Natural Resources, Geological Survey Bureau</publisher-name>. Open File Report 87-2. <publisher-loc>Iowa City</publisher-loc>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Birks, H.H.</surname></name>, <name name-style="western"><surname>Birks, H.J.B.</surname></name>, <name name-style="western"><surname>Kaland, P.E.</surname></name> and <name name-style="western"><surname>Moe, D.</surname></name>
<year>1988</year>: <source>The cultural landscape - past, present and future</source>. <publisher-loc>Cambridge</publisher-loc>: <publisher-name>Cambridge University Press</publisher-name>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Birks, H.H.</surname></name>, <name name-style="western"><surname>Whiteside, M.C.</surname></name>, <name name-style="western"><surname>Stark, D.M.</surname></name>, and <name name-style="western"><surname>Bright, R.C.</surname></name>
<year>1976</year>: <article-title>Recent paleolimnology of three lakes in northwestern Minnesota</article-title> . <source>Quaternary Research</source>
<volume>6</volume>, <fpage>249</fpage>-<lpage>72</lpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Blatchley, W.S.</surname></name> and <name name-style="western"><surname>Leng, C.W.</surname></name>
<year>1916</year>: <source>Rhynchophora or weevils of north eastern America</source>. <publisher-loc>Indianapolis</publisher-loc>: <publisher-name>Nature Publications</publisher-name>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Bousquet ,Y.</surname></name>
<year>1990</year>: <source>Beetles associated with stored products in Canada: an identification guide</source>. <publisher-loc>Ottawa</publisher-loc>, Canada: <publisher-name>Agriculture Canada Research Branch</publisher-name> Publication 1837.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Bradbury, J.P.</surname></name> and <name name-style="western"><surname>Waddington, J.C.B.</surname></name>
<year>1973</year>: <source>The impact of European settlement on Shagawa Lake, northeastern Minnesota, U.S.A</source>. In <name name-style="western"><surname>Birks, H.J.B.</surname></name> and <name name-style="western"><surname>West, R.G.</surname></name>, editors, <source>Quaternary Plant Ecology</source>, <publisher-loc>Oxford</publisher-loc>: <publisher-name>Blackwell</publisher-name>, <fpage>289</fpage>-<lpage>317</lpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Brown, H.P.</surname></name>
<year>1976</year>: <source>Aquatic dryopoid beetles (Coleoptera) of the United States</source> . <publisher-loc>Cincinnati, Ohio</publisher-loc>, USA: <publisher-name>US Environmental Protection Agency Water Pollution Control Research</publisher-name> Series 18050-ELD04/72.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Brugham, R.B.</surname></name>
<year>1978</year>: <article-title>Human disturbance and the historical development of Linsley Pond</article-title>. <source>Ecology</source>
<volume>59</volume>, <fpage>19</fpage>-<lpage>36</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Buckland, P.C.</surname></name> and <name name-style="western"><surname>Kenward, H.K.</surname></name>
<year>1973</year>: <article-title>Thorne Moor: a palaeo-ecological study of a Bronze Age site</article-title>. <source>Nature</source>
<volume>241</volume>, <fpage>405</fpage>-<lpage>406</lpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Chumbley, C.A.</surname></name>
<year>1988</year>: <source>Late glacial and Holocene vegetation</source>. In <name name-style="western"><surname>Green, W.</surname></name>, editor, <source>Archaeological and paleoenvironmental studies in the Turkey River Valley, northeastern Iowa</source>, Report to the <publisher-name>Iowa State Preserves Board</publisher-name>, <fpage>74</fpage>-<lpage>109</lpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple">— <year>1989</year>: <source>Late-glacial and Holocene vegetation of the Roberts Creek Basin, northeast Iowa</source>. <publisher-name>University of Iowa</publisher-name> Ph.D. Dissertation, <fpage>154</fpage> pp.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Chumbley, C.A.</surname></name>, <name name-style="western"><surname>Baker, R.G.</surname></name> and <name name-style="western"><surname>Bettis III, E.A.</surname></name>
<year>1990</year>: <article-title>Midwestern Holocene paleoenvironments revealed by floodplain deposits in northeastern Iowa</article-title>. <source>Science</source>
<volume>249</volume>, <fpage>272</fpage>-<lpage>74</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Cwynar, L.C.</surname></name>, <name name-style="western"><surname>Burden, E.</surname></name> and <name name-style="western"><surname>McAndrews, J.H.</surname></name>
<year>1979</year>: <article-title>An inexpensive method for concentrating pollen and spores from fine grained sediments</article-title>. <source>Canadian Journal of Earth Sciences</source>
<volume>16</volume>, <fpage>1115</fpage>-<lpage>20</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Davis, M.B.</surname></name>
<year>1973</year>: <article-title>Pollen evidence of changing land use around the shores of Lake Washington. Northwest</article-title>
<source>Science</source>
<volume>47</volume>, <fpage>133</fpage>-<lpage>48</lpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple">— <year>1989</year>: <source>Retrospective studies</source>. In <name name-style="western"><surname>Likens, G.E.</surname></name>, editor, <source>Long-term studies in ecology, approaches and alternatives</source>, <publisher-loc>New York</publisher-loc>: <publisher-name>Springer-Verlag</publisher-name> , <fpage>71</fpage>-<lpage>89</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Delcourt, P.A.</surname></name>, <name name-style="western"><surname>Delcourt, H.R.</surname></name>, <name name-style="western"><surname>Cridlebaugh, P.A.</surname></name> and <name name-style="western"><surname>Chapman, J.</surname></name>
<year>1986</year>: <article-title>Holocene ethnobotanical and paleoecological record of human impact on vegetation in the Little Tennessee River Valley, Tennessee</article-title> . <source>Quaternary Research</source>
<volume>25</volume>, <fpage>330</fpage>-<lpage>49</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Dick, W.</surname></name> and <name name-style="western"><surname>Tabatabai, M.A.</surname></name>
<year>1977</year>: <article-title>An alkaline oxidation method for the determination of total phosphorous in soils</article-title>. <source>Soil Science Society of America Proceedings</source>
<volume>41</volume>, <fpage>511</fpage>-<lpage>14</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Elias, S.A.</surname></name>
<year>1986</year>: <article-title>Fossil insect evidence for late Pleistocene paleoenvironments of the Lamb Spring site, Colorado</article-title>. <source>Geoarchaeology</source>
<volume>1</volume>, <fpage>381</fpage>-<lpage>87</lpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple">— <year>1990</year>: <source>The timing and intensity of environmental changes during the Paleoindian period in western North America: evidence from the insect fossil record</source>: In <name name-style="western"><surname>Agenbroad, L.</surname></name>, <name name-style="western"><surname>Mead, J.</surname></name> and <name name-style="western"><surname>Nelson, L.</surname></name>, editors, <source>Megafauna and man</source>, <publisher-loc>Flagstaff</publisher-loc>: <publisher-name>Northern Arizona University Press</publisher-name>, <fpage>11</fpage>-<lpage>14</lpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Faegri, K.</surname></name>, <name name-style="western"><surname>Kaland, P.E.</surname></name> and <name name-style="western"><surname>Krzywinski, K.</surname></name>
<year>1989</year>: <source>Textbook of Pollen Analysis</source>. <publisher-loc>New York</publisher-loc> : <publisher-name>John Wiley and Sons</publisher-name>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Freitag, R.</surname></name>
<year>1969</year>: <article-title>A revision of the species of the genus Evarthrus LeConte (Coleoptera: Carabidae)</article-title>. <source>Quaestiones Entomologicae</source>
<volume>5</volume>, <fpage>89</fpage>-<lpage>212</lpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>General Land Office Survey of Wisconsin Territory</surname></name>
<year>1837</year>-<year>1849</year>. <name name-style="western"><surname>Gleason, H.A.</surname></name> and <name name-style="western"><surname>Cronquist , A.</surname></name>
<year>1963</year>: <source>Manual of vascular plants of northeastern United States and adjacent Canada</source> . <publisher-loc>New York</publisher-loc>: <publisher-name>D. Van Nostrand</publisher-name>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Godfrey, L.D.</surname></name> and <name name-style="western"><surname>Yeargan, K.V.</surname></name>
<year>1989</year>: <article-title>Effects of clover root curculio, alfalfa weevil (Coleoptera: Curculionidae), and soil-borne fungi on alfalfa stand density and longevity in Kentucky</article-title>. <source>Journal of Economic Entomology</source>
<volume>82</volume>, <fpage>1749</fpage>-<lpage>56</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Gordon, R.D.</surname></name>
<year>1985</year>: <article-title>The Coccinellidae (Coleoptera) of America north of Mexico</article-title> . <source>Journal of the New York Entomological Society</source>
<volume>93</volume>, <fpage>1</fpage>-<lpage>912</lpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Harde, K.W.</surname></name>
<year>1981</year>: <source>A field guide in colour to beetles</source>. <publisher-loc>London</publisher-loc>: <publisher-name>Octopus Books</publisher-name>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Hisenoff, W.L.</surname></name>
<year>1977</year>: <source>Use of arthropods to evaluate water quality of streams</source> . <publisher-name>Wisconsin Department of Natural Resources</publisher-name> (<publisher-loc>Madison</publisher-loc>) Technical Bulletin No. 100, <fpage>15</fpage> pp.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Hoffman, A.</surname></name>
<year>1954</year>: <article-title>Faune de France. 59. Coléoptères curculiondes (Deuxieme Partie)</article-title>. <publisher-loc>Paris</publisher-loc>: Federation Francaise des Sociétés de <source>Sciences Naturelles</source>.</citation>
</ref>
<ref>
<citation citation-type="other" xlink:type="simple">Iowa State Census 1856.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>James, L.A.</surname></name>
<year>1991</year>: <article-title>Incision and morphologic evolution of an alluvial channel recovering from hydraulic mining sediment</article-title>. <source>Geological Society of America Bulletin</source>
<volume>103</volume>, <fpage>723</fpage>-<lpage>36</lpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Johnson, J.P.</surname></name>
<year>1944</year>: <source>The imported long-horned weevil Calymycterus setarius Roelofs. Bulletin of the Connecticut</source>
<publisher-name>Agricultural Experiment Station</publisher-name>
<fpage>19</fpage>, <fpage>121</fpage>-<lpage>42</lpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Johnson, W.C.</surname></name>, editor, <year>1987</year>: <source>Quaternary environments of Kansas</source>. <publisher-name>Kansas Geological Survey, Guidebook</publisher-name> Series 5, <publisher-loc>Lawrence</publisher-loc> .</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Johnson-Cicalese, J.M.</surname></name>, <name name-style="western"><surname>Wolfe, G.W.</surname></name> and <name name-style="western"><surname>Funk, C.R.</surname></name>
<year>1990</year>: <article-title>Biology, distribution, and taxonomy of billbug turf pests (Coleoptera: Curculionidae)</article-title>. <source>Environmental Entomology</source>
<volume>19</volume>, <fpage>1037</fpage>-<lpage>46</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Kennedy, J.O.</surname></name> and <name name-style="western"><surname>Miller III, J.G.</surname></name>
<year>1990</year>: <article-title>A survey of the benthic macroinvertebrates of the Big Spring Basin, Iowa</article-title>. <source>Journal of the Iowa Academy of Sciences</source>
<volume>97</volume>, <fpage>46</fpage>-<lpage>54</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Kenward, H.K.</surname></name>
<year>1976</year>: <article-title>Reconstructing ancient ecological conditions from insect remains; some problems and an experimental approach</article-title>. <source>Ecological Entomology</source>
<volume>1</volume>, <fpage>7</fpage>-<lpage>17</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Knox, J.C.</surname></name>
<year>1987</year>: <article-title>Historical valley floor sedimentation in the Upper Mississippi Valley</article-title>. <source>Annals of the Association of American Geographers</source>
<volume>77</volume>, <fpage>224</fpage>-<lpage>44</lpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Lindroth, C.H.</surname></name>
<year>1957</year>: <source>The faunal connections between Europe and North America</source> . <publisher-loc>New York</publisher-loc>: <publisher-name>John Wiley and Sons</publisher-name> .</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple">— <year>1961</year>: <article-title>The ground-beetles (Carabidae, excl. Cicindelinae) of Canada and Alaska (2)</article-title>. <source>Opuscula Entomologica Supplementum</source>
<volume>20</volume>, <fpage>1</fpage>-<lpage>200</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple">— <year>1966</year>: <article-title>The ground-beetles (Carabidae, excl. Cicindelinae) of Canada and Alaska (4)</article-title>. <source>Opuscula Entomologica Supplementum</source>
<volume>29</volume>, <fpage>409</fpage>-<lpage>648</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple">— <year>1968</year>: <article-title>The ground-beetles (Carabidae, excl. Cicindelinae) of Canada and Alaska (5)</article-title>. <source>Opuscula Entomologica Supplementum</source>
<volume>33</volume>, <fpage>649</fpage>-<lpage>944</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Litsinger, J.A.</surname></name> and <name name-style="western"><surname>Apple, J.W.</surname></name>
<year>1984</year>: <article-title>Summer diapause of the clover leaf weevil, Hypera punctata and lesser clover leaf weevil, Hypera nigrirostris, in Wisconsin</article-title>. <source>Great Lakes Entomologist</source>
<volume>17</volume>, <fpage>83</fpage>-<lpage>86</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Luff, M.L.</surname></name> and <name name-style="western"><surname>Rushton, S.P.</surname></name>
<year>1989</year>: <article-title>The ground beetle and spider fauna of managed and unimproved upland pasture</article-title>. <source>Agriculture Ecosystems and Environments</source>
<volume>25</volume>, <fpage>195</fpage>-<lpage>205</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Magilligan, F.J.</surname></name>
<year>1985</year>: <article-title>Historical floodplain sedimentation in the Galena River basin</article-title>, <publisher-loc>Wisconsin</publisher-loc> and <publisher-loc>Illinois</publisher-loc>. <source>Annals of the Association of American Geographers</source>
<volume>75</volume>, <fpage>583</fpage>-<lpage>94</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Maher, L.J.</surname></name>, Jr. <year>1977</year>: <article-title>Palynological studies in the western arm of Lake Superior</article-title>. <source>Quaternary Research</source>
<volume>7</volume>, <fpage>14</fpage>-<lpage>44</lpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>McAndrews, J.H.</surname></name>
<year>1988</year>: <source>Human disturbance of North American forests and grasslands: The fossil pollen record</source>. In <name name-style="western"><surname>Huntley, B.</surname></name> and <name name-style="western"><surname>Webb III, T.</surname></name>, editors, <source>Vegetation history, Dortdrecht</source>: <publisher-name>Kluwer</publisher-name>, <fpage>673</fpage>-<lpage>97</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>McAvoy, T.J.</surname></name>, <name name-style="western"><surname>Kok, L.T.</surname></name>, and <name name-style="western"><surname>Trimble, J.T.</surname></name>
<year>1983</year>: <article-title>Biological studies of Ceutorhynchus punctiger (Coleoptera: Curculionidae) on dandelion in Virginia</article-title>. <source>Annals of the Entomological Society of America</source>
<volume>76</volume>, <fpage>671</fpage>-<lpage>74</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>McLeod, J.M.</surname></name>
<year>1980</year>: <article-title>Forests, disturbances, and insects</article-title>. <source>The Canadian Entomologist</source>
<volume>112</volume>, <fpage>1185</fpage>-<lpage>92</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Moore, I.</surname></name>
<year>1979</year>: <article-title>Platystethus cornutus Gravenhorst reported from the United States is P. degener Mulsant and Rey (Coleoptera: Staphylinidae)</article-title>. <source>Coleopterists Bulletin</source>
<volume>33</volume>, <fpage>32</fpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Moore, I.</surname></name> and <name name-style="western"><surname>Legner, E.F.</surname></name>
<year>1971</year>: <article-title>A review of the nearctic species of Platystethus (Coleoptera: Staphylinidae)</article-title>. <source>Pan-Pacific Entomologist</source>
<volume>47</volume>,<fpage>260</fpage>-<lpage>64</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Osborne, P.J.</surname></name>
<year>1974</year>: <article-title>An insect assemblage of early Flandrian age from Lea Marston, Warwickshire, and its bearing on the contemporary climate and ecology</article-title>. <source>Quaternary Research</source>
<volume>4</volume>, <fpage>471</fpage>-<lpage>86</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple">— <year>1988</year>: <article-title>A late Bronze Age insect fauna from the River Avon, Warwickshire, England: its implications for the terrestrial and fluvial environment and for climate</article-title>. <source>Journal of Archaeological Science</source>
<volume>15</volume>, <fpage>715</fpage>-<lpage>27</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Puttler, B.</surname></name>, <name name-style="western"><surname>Thewke, S.E.</surname></name> and <name name-style="western"><surname>Warner, R.E.</surname></name>
<year>1973</year>: <article-title>Bionomics of three nearctic species, one new, of Hypera (Coleoptera: Curculionidae), and their parasites. Annals of the Entomological Society of</article-title>
<source>America</source>
<volume>66</volume>, <fpage>1299</fpage>-<lpage>1306</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Ratcliffe, B.C.</surname></name>
<year>1991</year>: <article-title>The scarab beetles of Nebraska</article-title>. <source>Bulletin Nebraska State Museum</source>
<volume>12</volume>, <fpage>1</fpage>-<lpage>333</lpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Sailer, R.I.</surname></name>
<year>1983</year>: <source>History of insect introductions</source>. In <name name-style="western"><surname>Wilson, C.L.</surname></name> and <name name-style="western"><surname>Graham, C.L.</surname></name>, editors, <source>Exotic plant pest and North American agriculture</source> , <publisher-loc>New York</publisher-loc>: <publisher-name>Academic Press</publisher-name>, <fpage>15</fpage>-<lpage>38</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Sartz, R.S.</surname></name>
<year>1975</year>: <article-title>Controlling runoff in the Driftless Area</article-title>. <source>Journal of Soil and Water Conservation</source>
<volume>30</volume>, <fpage>92</fpage>-<lpage>93</lpage>.</citation>
</ref>
<ref>
<citation citation-type="confproc" xlink:type="simple">— <conf-date>1976</conf-date>: <article-title>Sediment yield from steep lands in the Driftless Area</article-title> . In <conf-name>Proceedings of the Third Federal Inter-Agency Sedimentation Conference</conf-name>, <conf-loc>Washington, D.C.: U.S. Government Printing Office</conf-loc>, I-123-31.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Smith, E.H.</surname></name>
<year>1985</year>: <article-title>Revision of the genus Phyllotera Chevrolat of America north of Mexico. Part I. The maculate species (Coleoptera: Chrysomelidae, Alticinae)</article-title>. <source>Fieldiana (Zoology, New Series)</source>
<volume>28</volume>, <fpage>1</fpage>-<lpage>168</lpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Soil Survey Staff</surname></name>
<year>1975</year>: <source>Soil Taxonomy</source>. <publisher-loc>Washington, D.C.</publisher-loc>: <publisher-name>U.S. Department of Agriculture Handbook</publisher-name>
<fpage>436</fpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Tsukada, M.</surname></name>
<year>1972</year>: <article-title>The history of Lake Nojiri, Japan. Connecticut Academy of Arts and Sciences</article-title>
<source>Transactions</source>
<volume>44</volume>, <fpage>339</fpage>-<lpage>65</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Turnbull, A.L.</surname></name>
<year>1980</year>: <article-title>Man and insects: the influence of human settlement on the insect fauna of Canada</article-title>. <source>The Canadian Entomologist</source>
<volume>112</volume>, <fpage>1177</fpage>-<lpage>84</lpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Vaurie, P.</surname></name>
<year>1983</year>: <source>A catalog of the Coleoptera of America north of Mexico. Family: Curculionidae. Subfamily: Rhynchophorinae</source>. <publisher-loc>Washington, D.C.</publisher-loc>: <publisher-name>U.S. Department of Agriculture Handbook</publisher-name>
<fpage>529</fpage>-<lpage>143</lpage>a.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>Walter, N.F.</surname></name>, <name name-style="western"><surname>Hallberg, G.R.</surname></name> and <name name-style="western"><surname>Fenton, T.E.</surname></name>
<year>1978</year>: <source>Particle-size analysis by the Iowa State University Soil Survey Laboratory</source>. In <name name-style="western"><surname>Hallberg, G.R.</surname></name>, editor, <source>Standard Procedures for Evaluation of Quaternary Materials in Iowa</source>, <publisher-loc>Iowa City</publisher-loc>: <publisher-name>Iowa Geological Survey</publisher-name>, Technical Information Series No. 8, <fpage>61</fpage>-<lpage>74</lpage>.</citation>
</ref>
<ref>
<citation citation-type="book" xlink:type="simple"><name name-style="western"><surname>WebbIII, T.</surname></name>, <name name-style="western"><surname>Cushing, E.J.</surname></name> and <name name-style="western"><surname>Wright, H.E.</surname></name>, Jr. <year>1983</year>: <source>Holocene changes in vegetation of the Midwest</source> . In <name name-style="western"><surname>Wright, H.E.</surname></name>, Jr., editor, <source>Late Quaternary environments of the United States, Volume 2, The Holocene</source> , <publisher-loc>Minneapolis</publisher-loc>: <publisher-name>University of Minnesota Press</publisher-name>, <fpage>142</fpage>-<lpage>65</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Weiss, M.J.</surname></name>, <name name-style="western"><surname>Balsbaugh, E.U.</surname></name>, Jr., <name name-style="western"><surname>French, E.W.</surname></name> and <name name-style="western"><surname>Hoag, B.K.</surname></name>
<year>1990</year>: <article-title>Influence of tillage management and cropping system on ground beetle (Coleoptera: Carabidae) fauna in the northern Great Plains</article-title>. <source>Environmental Entomology</source>
<volume>19</volume>, <fpage>1388</fpage>-<lpage>91</lpage>.</citation>
</ref>
<ref>
<citation citation-type="journal" xlink:type="simple"><name name-style="western"><surname>Yeomans, J.C.</surname></name> and <name name-style="western"><surname>Bremner, J.C.</surname></name>
<year>1991</year>: <article-title>Carbon and nitrogen analysis of soils by automated combustion techniques. Communications in Soil Science and Plant</article-title>
<source>Analysis</source>
<volume>22</volume>, <fpage>843</fpage>-<lpage>850</lpage>.</citation>
</ref>
</ref-list></back></article></istex:document></istex:metadataXml><mods version="3.6"><titleInfo lang="en"><title>Impact of Euro-American settlement on a riparian landscape in northeast Iowa, midwestem USA: an integrated approach based on historical evidence, floodplain sediments, fossil pollen, plant macrofossils and insects</title></titleInfo><titleInfo type="alternative" lang="en" contentType="CDATA"><title>Impact of Euro-American settlement on a riparian landscape in northeast Iowa, midwestem USA: an integrated approach based on historical evidence, floodplain sediments, fossil pollen, plant macrofossils and insects</title></titleInfo><name type="personal"><namePart type="given">R.G.</namePart><namePart type="family">Baker</namePart><affiliation>Department of Geology, University of Iowa, Iowa City, Iowa 52242-1379, USA</affiliation></name><name type="personal"><namePart type="given">D.P.</namePart><namePart type="family">Schwert</namePart><affiliation>Department of Geosciences, North Dakota State University, Fargo, North Dakota 58105-5517, USA</affiliation></name><name type="personal"><namePart type="given">E.A.</namePart><namePart type="family">Bettis</namePart><affiliation>Iowa Department of Natural Resources, Geological Survey Bureau, 123 N Capitol, Iowa City, Iowa 52242, USA</affiliation></name><name type="personal"><namePart type="given">C.A.</namePart><namePart type="family">Chumbley</namePart><affiliation>412 Highland Avenue, Iowa City, Iowa 52242, USA</affiliation></name><typeOfResource>text</typeOfResource><genre type="research-article" displayLabel="research-article" authority="ISTEX" authorityURI="https://content-type.data.istex.fr" valueURI="https://content-type.data.istex.fr/ark:/67375/XTP-1JC4F85T-7">research-article</genre><originInfo><publisher>Sage Publications</publisher><place><placeTerm type="text">Sage CA: Thousand Oaks, CA</placeTerm></place><dateIssued encoding="w3cdtf">1993-12</dateIssued><copyrightDate encoding="w3cdtf">1993</copyrightDate></originInfo><language><languageTerm type="code" authority="iso639-2b">eng</languageTerm><languageTerm type="code" authority="rfc3066">en</languageTerm></language><abstract lang="en">European settlement and attendant forest clearance and agricultural activities in northeastern Iowa caused changes in the landscape, vegetation, insect fauna and water quality unequalled in rate and magnitude since the melting of Wisconsinan glaciers. Historical documents show that the upper part of the Roberts Creek drainage basin was settled between AD 1840 and 1856, and the area was under intensive cultivation by 1880. Extensive soil erosion beginning at this time resulted in increased runoff and more frequent flooding; aggradation rates increased by one to two orders of magnitude over those in presettlement times, and the entire floodplain was covered with up to 1 m of sediment. Channel widening between about 1880 and 1930 allowed the stream to accommodate greater floods, overbank deposition decreased, and further deposits were restricted mostly to the channel belt. The presettlement vegetation was a stable mix of wet meadows and riparian shrubs on the floodplain, a rich aquatic community in the stream, and oak savanna on the valley walls and upland. Disturbance from soil erosion, floodplain erosion and floodplain deposition almost completely replaced both lowland and upland communities with ruderal (disturbed ground) plants, many of them introduced weeds. Regional insect communities were simultaneously affected by changes in land use. The presettlement aquatic beetle fauna was dominated by species of dryopoid beetles that today inhabit only streams of high water quality. Terrestrial beetle taxa included species of undisturbed grasslands and riparian forest. The changes in the landscape resulted in a decrease in the diversity of terrestrial beetle taxa and caused the near total elimination of dryopoid beetles in stream waters. Dominating the historic assemblages are beetles associated with dung, polluted waters and cultivated plants, including host-specific immigrant beetle species that are associated with immigrant plant species.</abstract><subject><genre>keywords</genre><topic>Euro-American settlement</topic><topic>human impact</topic><topic>riparian landscape</topic><topic>cultural landscape</topic><topic>historical evidence</topic><topic>floodplain sediments</topic><topic>pollen</topic><topic>macrofossils</topic><topic>insects</topic><topic>Iowa</topic><topic>midwest.</topic></subject><relatedItem type="host"><titleInfo><title>Holocene (Sevenoaks)</title></titleInfo><genre type="journal" authority="ISTEX" authorityURI="https://publication-type.data.istex.fr" valueURI="https://publication-type.data.istex.fr/ark:/67375/JMC-0GLKJH51-B">journal</genre><identifier type="ISSN">0959-6836</identifier><identifier type="eISSN">1477-0911</identifier><identifier type="PublisherID">HOL</identifier><identifier type="PublisherID-hwp">sphol</identifier><part><date>1993</date><detail type="volume"><caption>vol.</caption><number>3</number></detail><detail type="issue"><caption>no.</caption><number>4</number></detail><extent unit="pages"><start>314</start><end>323</end></extent></part></relatedItem><identifier type="istex">9B6AE279BE1A6C106F2CDBB822870FBB56258972</identifier><identifier type="ark">ark:/67375/M70-5L16Z0KV-C</identifier><identifier type="DOI">10.1177/095968369300300403</identifier><identifier type="ArticleID">10.1177_095968369300300403</identifier><recordInfo><recordContentSource authority="ISTEX" authorityURI="https://loaded-corpus.data.istex.fr" valueURI="https://loaded-corpus.data.istex.fr/ark:/67375/XBH-0J1N7DQT-B">sage</recordContentSource></recordInfo></mods><json:item><extension>json</extension><original>false</original><mimetype>application/json</mimetype><uri>https://api.istex.fr/document/9B6AE279BE1A6C106F2CDBB822870FBB56258972/metadata/json</uri></json:item></metadata><serie></serie></istex></record>Pour manipuler ce document sous Unix (Dilib)
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