Vegetation restoration and spatial variation of soil nutrient content in a hill-pond landscape

A hilltop-pond landscape is an excellent agro-forestry system. The spatial variation of soil nutrient in this landscape was studied. By analyzing soil nutrient total N, total P and organic C in patches and comprising the difference of soil nutrient contents of pre-afforestation (1986) and post-afforestation(2002). The soil nutrient contents among the landscape have vertical variability. The distribution of nutrients on landscape at different depths was different. The nutrient content variaton decreased with the increase of the depth of soil. The soil nutrient content mainly concentrated at the depth of 0～10 cm and decreased as the soil depth increased. The smallest C.V 19.68% is the fish-pond surface soil and the biggest is grass-land which reaches 56.8%. The C.V of the organic C(OC) and the total N(TN) is similar, decreasing with the soil depth. The contents of TN and OC in forest-land are larger than other patches. The content decreased from upgrade to downgrade. The content of TC in forest is 1.84%, in garden 1.20%, in grass land 1.07%, fish-pond 0.80%. The contents of TN(μ g/g) are 1329.63, 846.19, 663.25, respectively. The contents of TP(μg/g) 441.26 in garden, 268.62 in grass land, 259.12 in fish-pond, 157.92 in forest land, respectively. The distributions of content of organic C, total N and total P have remarkably spatial heterogeneity. The rule of organic C, total N is more obvious than that of total P.