黄土丘陵沟壑区退耕地植物群落与土壤环境因子的对应分析

CORRESPONDENCE ANALYSIS OF VEGETATION COMMUNITIES AND SOIL ENVIRONMENTAL FACTORS ON ABANDONED CROPLAND ON HILLY-GULLIED LOESS PLATEAU

根据在黄土高原丘陵沟壑区安塞33个退耕地自然恢复植被样方的调查数据,采用对应分析(Correspondence Analysis)和典范对应分析(Canonical Correspondence Analysis)进行了植物群落排序和植物群落与土壤环境因子的对应分析。结果表明:在40 a的演替过程中,退耕地植被大体上依次经历了猪毛蒿(Artemisia scoparia)为优势种的群落、达乌里胡枝子(Lespedeza davurica)和长芒草(Stipa bungeana)为优势种的群落、铁杆蒿(Artemisia gmelinii)为优势种的群落和白羊草(Bothriochloa ischaemun)为优势种的群落,4个群落的物种组成表现出较强的延续性和递进性。4个植物群落的土壤特性有明显的差异,对于0-60 cm土层的土壤养分和0- 500 cm土层的土壤水分,群落1的土壤水分和速效磷含量较高;群落2的全氮、速效氮含量较高;群落3的全磷和200-500 cm土层的水分含量较高;群落4的速效钾、土壤有机质含量较高。全磷、速效磷、土壤有机质和0-200 cm土层的土壤水分含量是显著影响黄土丘陵沟壑区退耕地植物群落变化的主要因子。要加速退耕地植被恢复和有效防止土壤流失,人工引种补播适宜物种和施肥值得重视。

Based on observation of 33 plots of abandoned farmland in Ansai, a loess region of hills and gullies, sequence of vegetation communities and their relationships with soil environmental factors in these fields were analyzed through Correspondence Analysis and Canonical Correspondence Analysis. The results show that there are mainly 4 vegetation communities during 40 years of succession ： Artemisia scoparia dominated community （ Ⅰ ）, Lespedeza davurica and Stipa bungeana dominated com- munity （ Ⅱ ）, Artemisia gmelinii dominated community （ Ⅲ ） and Bothriochloa ischaemun dominated community （ Ⅳ ）. The species compositions of the 4 communities displayed relatively strong continuity and progressiveness. In comparison, the soil under Community Ⅰ was higher in soil moisture content in 0 - 200 cm layers and available phosphorus content, Community Ⅱ in total nitrogen and available nitrogen content, Community Ⅲ in total phosphorus content and soil water content in 200 - 500 cm layers, and Community Ⅳ in available potassium and organic matter content. Organic matter, total phosphorus, available phosphorus and soil water content in 0 - 200 cm layers are important factors significantly affecting variation of vegetation on abandoned cropland in the hilly-gullied Loess Plateau. To revegetate the land quickly and control soil erosion effectively, it is essential to take measures such as transplanting or sowing C4 plants and applying fertilizers.