自然封育对云雾山草地群落的影响

Effects of Natural Enclosing on Grassland Communities in Yunwu Mountain

对云雾山封育和未封育草地土壤水分、养分、团聚体含量以及群落结构进行了对比研究。结果表明,0—20 cm为草地土壤含水量活跃层,同时封育草地和未封育草地的水分补偿深度分别为140 cm和20cm;随土层深度增加,草地中>1 mm和>0.25 mm粒径团聚体含量逐渐递减,封育草地>1 mm和>0.25mm粒径的团聚体含量均高于未封育草地;除速效P外,封育草地较未封育草地具有较高的土壤有机质、全氮、速效钾、硝态氮、铵态氮和碱解氮含量;未封育草地和封育草地群落的物种数,Simpson指数,Shannon—Wiener指数和均匀度相近,而植物的平均高度和盖度为未封育草地<封育草地。

This article contrasted the enclosed and unenclosed grasslands for soil water, soil nutrients, water stable aggregates, and community structure. Results showed that in grasslands, soil water active layer was 0--20 cm, and meanwhile, compensatory depths were 140 cm and 20 cm in enclosed and unenclosed grass lands, respectively. Below the depths, soil water content kept the level of 9.5% and 8.5% in enclosed and unenclosed grasslands, respectively. With soil depth increased, soil water stable aggregate content （〉1 and 〉0.25 mm） was reduced gradually and in enclosed grassland, it was greater than that in unenclosed grassland. Except the available P, the contents of soil organic matter, total N, available K, available N, NO3 N and NH4＋ -N in enclosed grassland were much greater than those in unenclosed grassland. The number of species, Simpson index, Shannon-Wiener index, and Pielou index in the two grasslands were similar. The average plant height and coverage in unenclosed grassland were less than those in enclosed grassland and the differences were significant.