陕北白于山区草地返青期地形·土壤水分与群落结构的关系

Relationship among Terrain,Soil Water and Community Structure in Grass Turning Green Period in Baiyu Mountain of Northern Shaanxi

研究了陕北白于山区草地返青期地形、土壤水分与群落结构的关系。结果表明，0-40、40-80、80-120cm土层的土壤含水量与120-160cm土层的土壤含水量之间相关性极显著；地形因子中的海拔与200-240cm土层含水量呈负相关；坡位与160-240am土层土壤含水量呈正相关，坡向与80-120cm土层土壤含水量呈负相关；坡度与240-280cm土层土壤含水量呈正相关；草地的盖度与80-120cm土层土壤含水量呈正相关，草地的生物量与40-120cm土层土壤含水量呈正相关，草本植物的物种丰富度受土壤含水量的影响较弱。地形因子中的海拔与草地群落的盖度和生物量呈正相关，坡位与生物量呈负相关，与物种丰富度呈正相关；而坡向与物种丰富度呈正相关，坡度对草地群落指数影响不显著。

The paper analyzed the relationship between grass turning green period, soil water and community structure. The results showed that the soil water contents of 0-40, 40-80, 80-120 cm soil layer and 120-160 cm had significant correlation ; Altitude of terrain factor had negative correlation with 200-240 cm layer soil water contents; Slope position had positive correlation with 160-240 cm layer soil water contents; Slope direction had negative correlation with 80-120 cm layer soil water contents; Slope degree had positive correlation with 240-280 cm layer soil water contents; Coverage of grass had positive correlation with 80 -120 cm layer soil water contents; Biomass of grass had positive correlation with 40 - 120 cm layer soil water contents; Species richness of herb had week effects on soil water content. Altitude of ter- rain factor had positive correlation with the coverage and biomass of grass communication, slope position had negative correlation with biomass, and had positive correlation with species richness; while slope direction had positive correction with species richness, and slope degree had no significant effects on grass community index.