Abstract:

Urbanization is increasing worldwide and impacting native ecosystems through disturbance, climatic modification, and pollutant deposition. In order to better understand and quantify the potential effects of human activities on soil properties and its spatial pattern in urban ecosystems, the contents and spatial distribution of pH, total nitrogen (TN), total phosphorus (TP) and available phosphorus (AP) in the surface soils (0~10 cm) of urban greenland were studied in central Hefei using GIS technology and geostatistical analysis. A total of 105 sites was sampled over 20 km2 in central Hefei. The results showed that the soil pH was within a range of 67 to 88 with a coefficient of variation (CV) of 50%. The concentrations of TN ranged from 292 to 3 789 mg/kg with CV of 475%. The TP concentrations were from 147 to 2 470 mg/kg with CV of 687% and AP were 56~1064 mg/kg with CV of 657%. The theoretical semivariogram models for soil pH and AP were best fitted by the spherical model, while for TN and TP were best fitted by the exponential model. The spatial variability of TP was mainly resulted from structural factors, and had high spatial correlation. However, the spatial variability of soil pH, TN and AP was caused by both random factors and structural factors. The spatial correlation for soil pH, TN and AP was moderate. In addition, soil total N was significantly and positively correlated with pH. Soil available P was significantly and positively correlated with total P. The spatial distributions of soil pH, TN, TP and AP in urban Hefei were analyzed by the Kriging interpolation method