生境片段化对千岛湖次生马尾松林土壤理化性质的影响

土壤是森林生态系统的重要组成部分，对森林生物多样性和生态功能的维持具有不可替代的作用.据此，本研究以千岛湖地区大陆35个样方和29个不同大小和隔离度的陆桥岛屿次生马尾松林土壤为研究对象，分析了生境片段化对土壤理化性质的影响.研究发现，大陆马尾松林土壤厚度显著高于岛屿，而其土壤最大持水量显著低于岛屿；大陆土壤的全磷（P）显著低于岛屿，而土壤有效磷（AP）和硝态氮（NO₃-N）显著高于岛屿.在片段化的岛屿生境中，土壤C、N、P、NO₃-N、AP随与边缘距离的增大而降低；隔离度和地形对部分土壤理化因子有影响，而岛屿面积对土壤理化性质无影响.土壤理化因子和植物群落多样性存在显著相关性.生境片段化改变了千岛湖地区马尾松林的土壤条件，而边缘效应是影响片段化生境中土壤性质空间分布的主要过程之一.通过分析片段化景观中土壤理化性质的空间分布格局及其影响因素，深化了生境片段化对土壤条件影响的认识，对于片段化森林管理措施的制定具有重要意义.

Effects of habitat fragmentation on soil properties of the secondary Masson pine (Pinus massoniana) forests of the Thousand Island Lake region

Soil is an important part of the forest ecosystem, and plays a critical role in maintaining forest biodiversity and function. We investigated the spatial distributions of physical and chemical properties of the soil of the secondary Masson pine (Pinus massoniana) forests on mainland and 29 land-bridge islands in the Thousand Island Lake region, to explore the effects of habitat fragmentation on soil. It is found that soil thickness on mainland is higher than on islands, while its soil maximum water content is lower on mainland than on islands; Other facts include:soil total phosphorus(P) is lower on mainland than on islands; soil available phosphorus (AP) and nitrate (NO₃-N) are higher on mainland than on islands. Among the islands, soil C, N, P, NO₃-N and AP decrease with the distance from the edge of island; The isolation and geography of each island would affect soil property, while the island area has little impacts. Further, it exhibits significant correlations between the soil physical-chemical properties and the biodiversity of in site aboveground plant community. The results suggest that habitat fragmentation changes the soil conditions of Masson pine forests in the Thousand Island Lake region. Edge effect might be a major process that shapes the distribution of soil conditions. Understandings of the determinants of spatial distribution patterns of soil properties under habitat fragmentation are of great importance to the development of forest management plans for fragmented forests.