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

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、80~120 cm土层的土壤含水量与120~160 cm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200~240 cm土层含水量呈负相关;坡位与160~240 cm土层土壤含水量呈正相关,坡向与80~120 cm土层土壤含水量呈负相关;坡度与240~280 cm土层土壤含水量呈正相关;草地的盖度与80~120 cm土层土壤含水量呈正相关,草地的生物量与40~120 cm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。

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

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 terrain 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.