Soil faunal community structure in winter season under variousland use types in Guangzhou

Rapid urbanization process changes the spatial pattern of land utilization, soil physical and chemical properties. As an important part of urban ecosystem, soil animals have been used in monitoring researches of many environmental problems from urbanization, in which some of them may be used as indicator species to monitor and evaluate soil quality and health as well as one of the main influential factors on material cycles. To better know the impacts of urbanization on soil animals community and soil ecosystem, we took Tianhe and Yuexiu Districts of Guangzhou City as a case study area, 6 sites from three different land use systems including the two woodlands, two grasslands and two farmlands were selected as the investigation sites in January 2008. Soil meso- and micro- faunal communities in six sites located in three different land use types were investigated. The total number and groups of soil meso- and micro- fauna genera sampled were 1 365 and 25 respectively, belonging to 7 phyla. Dominant genera were Nematoda, Acarina and Turbellaria, comprising 83.44% of total samples collected. The community complexity index (C), a measure of the complexity and diversity of the communities was highest (2.822) in forestland of the South China Botanical Garden plot and lowest in grassland of the Ren Min Park plot. The vertical distribution of soil meso- and micro-faunal communities in the six sampling plots showed clear surface assembly, with the total number of soil fauna and genera declining with soil depth. Detrended correspondence analysis indicated that soil animal communities responded differently to varying intensities of human activities. Rare genera within the Orders of Diplopoda and Archaeognatha could be only found in the two forestland plots and very sensitive to human disturbance, indicating that soil fauna within these two orders might be used to detect land use changes resulting from urbanization. The results of this study provided scientific and fundamental data for the indicative function of the soil quality change by giving a survey of variations of soil meso- and micro-faunal community's composition and distribution under the influences of rapid urbanization. Moreover, the study pointed out that future studies should integrate the studies of the soil animals and changes in land use type for the enhancement or improvement of soil quality.