丘塘景观植被恢复与土壤养分空间分异规律研究

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

丘塘景观是一种生态经济结构较为优化的人工复合生态系统.根据在丘塘景观内不同斑块的土壤调查,研究土壤养分的分异规律,为退化丘塘景观的恢复提供理论依据,并且对于水肥的调配和植被的恢复都有重要的意义.结果表明:土壤有机质含量的变化是随着土壤深度增加而减少的,全氮的变化趋势同有机质一样,随土壤深度增加而递减.土壤全磷并没有遵循此规律,基本上各个不同斑块土层10～20 cm含量都大于其他土层.不同斑块表层变异系数最小,往生层基本呈现上升趋势.土壤养分水平空间变异为0～10 cm土层土壤有机质和全氮平均含量分布为:林带>果园>草地>鱼塘,全磷平均含量分布是果园>林带>草地>鱼塘.通过比较造林前(1986年)和造林后(2002年)的土壤养分结果表明马占相思林对下层土壤有显著的影响,土壤有机碳和全氮含量大大提高.

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.