陕北黄土丘陵区撂荒演替前期群落异质性研究

采用典型相关分析方法,对陕北黄土丘陵区撂荒演替前期8块样地进行了群落间异质性和群落异质性分析。结果表明,群落间异质性大于群落异质性,且群落间异质性与环境因素差异多数为正相关,说明环境对撂荒演替前期群落组成与结构起到了一定的塑造作用。典型相关分析进一步表明,群落间异质性主要是群落组成异质性,有49.6%是由环境差异引起的。土壤全氮、磷和钾含量与群落间组成异质性有较强的正相关关系,说明氮、磷和钾肥对撂荒演替中群落组成有较大的影响。因此在草地植被恢复与重建工作中应注意肥料施用,特别是氮肥的施用。

Community Heterogeneity of Early Abandoned Arable Land in Loess Hilly Region of Northern Shaanxi Province

Canonical correlation analysis is used to analyze spatial heterogeneity and standing condition differentia of eight communities in early succession stage of abandoned arable land.Results show that spatial heterogeneities between communities are greater than those within communities.Spatial heterogeneities between communities have a positive relationship with most of standing condition differentia,both of which imply environments can act on community composition and structure of the early succession stage.Further canonical correlation analysis shows that environment differentia accounts for 49.6% of heterogeneities between communities.Heterogeneities between communities and nitrogen differentia show a strong positive relationship,which implies that nitrogen is the main factor acting on heterogeneities between communities.Besides nitrogen,soil phosphorus and potassium show a significant positive relationship,and therefore fertilizer,especially nitrogen should be fertilized in revegetated abandoned land.