SUITMA 2005 Cairo - Specific features of the development of urban and suburban phytopedocenoses
SUITMA 2005 Cairo
| This abstract is about one of the papers of the Properties of unconventional soils theme of the SUITMA 2005 symposium. |
| D.V. Moukha.i |
Growth of urban and suburban areas and the associated increase of human impact on the environment induced radical changes in soils, vegetative covers, and natural landscapes. The object of this paper is phytopedocenosis, i.e., an element of homogeneous territory from geomorphological and hydrothermic perspectives, with the same soil cover, phytocenosis, organisms, and regimes. Research was carried out in the territories of Kursk and its suburbs from the year 1995. Using the characteristic features of phytopedocenosis, we could divide the territories into recreation zones with different degrees of anthropogenic activities and different natural conditions: 1) recreation zones of the historical center, 2) recreation zones of the industrial center, and 3) newly formed recreation zones of the industrial center.
The newly formed recreation zones in the industrial center are characterized by the creation of new phytopedocenoses different from old urban and natural cenoses. The anthropogenic influence on the soil caused great changes. First, a new natural-anthropogenic soil profile is formed, genetic soil horizontation decreased, and the humus content is reduced and smoothed in the whole soil horizon. Furthermore, the soil is recompressed till the depth of 60 centimeters. Second, adsorbed Ca2+ is replaced by Mg2+ and H+ not only in the upper horizon, but also in the bottom horizons. Third, the negative anthropogenic-dependent soil characteristics are associated with an increase in most major nutrients contents. Fourth, there is a decrease in the number of microorganisms together with an increase in fungi microscopic flora. Fifth, the rise in the activity of ferments taking part in the oxidation of humus, i.e., microbe cenosis facilitated the mineralization of organic matter.
The phytopedocenosis differs quantitatively and qualitatively with the content of heavy metals in soil and vegetative cover. Differences in heavy metal contents of soils are explained by the duration of anthropogenic influence: the older is the recreation zone, the more cases of higher than Maximum Allowable Concentration (MAC) take place. In the historical center we can notice an increase of heavy metals at the depth of 10-20 cm. In the new industrial zones, pollutants contents in the soil are lower. However, the concentration of some elements, Pb in particular, is exceptionally high due to specification of industry and neighboring motorways.
