林型差异对土壤理化性状及其持水能力的影响

Impact of forest types on soil physical and chemical properties and waterholding capacities

为了探明林型差异对土壤理化特征及其持水能力的影响,采集老虎岭水源涵养林区域4种最典型的林型(马尾松林、马尾松-红锥林、马尾松-红锥-椆木林、红锥-大叶栎林)土壤进行理化特征及其持水能力测定分析。结果表明:土壤毛管孔隙度、持水能力和化学性质在4种林型中存在明显的差异,其中马尾松-红锥林土壤容重最小,总孔隙度和毛管孔隙度最大,最大持水量、毛管持水量、有机质、速效氮和速效磷最多;马尾松-红锥-椆木林非毛管孔隙度最大,全氮、全磷、速效钾和代换性镁最多;红锥-大叶栎林全钾最多;马尾松林土壤容重、非毛管持水量和代换性钙最大,总孔隙度、毛管孔隙度、自然含水率、最大持水量、毛管持水量、全量和速效养分均最低。总体表现,混交林型的土壤理化特征及持蓄能力均优于马尾松纯林,尤以马尾松-红锥林型为最佳。

To investigate the impact of forest types on soil physical and chemical properties and water-holding capacities, soil samples from 4 typical forest types in Laohuling watershed were tested, including Pinus massoniana, P. massoniana/Castanopsis hystrix, P. massoniana/C. hystrix/Lithocarpus thalassica and C. hystrix/Castanopsis fissa forests. The results showed that soil capillary porosity, water-holding capacity and chemical property presented significant differences among 4 forest types, and P. massoniana/Castanopsis hystrix forest had lowest bulk density; highest total porosity, capillary porosity, maximum water holding capacity, capillary moisture capacity, organic matter, available nitrogen, and available phosphorus. P. massoniana/C. hystrix/Lithocarpus thalassica forest had largest noncapillary porosity and highest total nitrogen, total phosphorus, available potassium and exchangeable magnesium. C. hystrix/Castanopsis fissa forest soil harbored highest total potassium. P. massoniana forest had highest bulk density, noncapillary water holding capacity and exchangeable magnesium; and lowest total porosity, capillary porosity, water content, maximum water holding capacity, capillary water holding capacity, total nutrients and available nutrients. In overall, mixed forests surpassed pure P. massoniana forest in soil physical and chemical properties and water-holding capacities, especially the mixed P. massoniana/Castanopsis hystrix forest.