石羊河下游沙蒿群落空间分布与土壤因子关系研究OA

In order to explore the mutual feedback relationship between the spatial distribution of Artemisia desertorum community and environmental factors,the community ecology survey of 50 A.desertorum plots was carried out in the lower reaches of Shiyang River during the growing season.Twelve soil physical and chemical factors such as water,grain size,total nitrogen,organic matter,available phosphorus and electrical conductivity were analyzed and determined in the laboratory.The key soil factors of spatial distribution of A.desertorum community were analyzed by quantitative ecological classification and ordination,and the succession process and soil driving mechanism of A.desertorum community were clarified.The results showed that there were 42 plant species belonging to 35 genera and 13 families in the A.desertorum com-munity in the lower reaches of Shiyang River.The two-way indicator species classification divided the A.desertorum community in the lower reaches of Shiyang River into eight associations.The spatial distri-bution of the eight associations reflects the environmental gradient changes dominated by soil water and fertilizer.The results of canonical correspondence analysis showed that soil factors explained 56.06%of the variance of A.desertorum community,and the order was total nitrogen(12.1%)>soil moisture(9.8%)>soil electrical conductivity(3.9%)=organic matter(3.9%)>soil clay(3.0%)>available phos-phorus(2.9%)>pH(2.6%)>soil sand(1.8%)>soil total salt(1.3%).Among them,total nitrogen and soil moisture are the most important soil regulating factors for the distribution of A.desertorum communi-ty in the lower reaches of Shiyang River.The restoration of degraded A.desertorum communities suggested that comprehensive measures such as improving soil structure,regulating soil nutrients,and improving soil moisture status should be taken in the lower reaches of Shiyang River.