The effect of land impoverishment on the population dynamics of soil microarthropods at Mahalet-Roh village, El-Mehala El-Kobra, Gharbia Governorate, Egypt was studied. The oribatid abundance in impoverished land showed a marked seasonal heterogeneity. Autumn was the most favorable season for the flourishing oribatid mites allover the year of study. However, Collembola showed low tendency towards seasonal fluctuation. Summer was the most favourable season for the abundance of Collembola. In the arable land, the population density was almost the same in spring and summer. During autumn and winter, the population density was slightly decreased. The diversity and equitability figures for the populations of the oribatid mites and Collembola species showed no obvious changes between sites. However, within sites, collembolan species showed a remarkable seasonal fluctuation of diversity. On the other hand, oribatid mites showed low figures of species diversity fluctuation as compared with those of Collembola. In conclusion, the extensive land-use can be considered among the main factors responsible for deterioration of soil fertility and productivity.
Key words: Oribatid mites, Collembola, population dynamics, arable land impoverishment.
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