ECOLOGICAL CHARACTERISTICS AND ROLES OF AGRIOPHYLLUM SQUARROSUM,A PIONEER ANNUAL ON SAND DUNES IN HEXI CORRIDOR,CHINA
会议名称：《第三世界生态高峰会》
会议日期：2007年
关 键 词：Agriophyllum squarrosum pioneer annual Hexi corridor ecological characteristics ecological role
摘 要：Agriophyllum squarrosum Moq,a therophyte of sandy soils,is considered as the best indicator of the beginning of community succession on shifting sand *** can dominate most of the shifting sand dunes,but its eco-charateristics and roles is known little,so t he experiment was conducted to understand the distribution and growth charateristics,ecological roles of such pioneer annual C4 grasses on shifting sand dunes in Hexi *** experiment was conducted at Minqin Desert Control Comprehensive Experimental Station（38°34′N,102°58′E）.The sampling method was adopted to investigated the distribution of on different land and *** plot size was 2m×2m,The plot number of each site was *** ten sampling plants were selected to observed modules and growth pattern of *** wind breaking and sand stabilizing of *** individual and *** community were observed by the portable wind velocity measuring *** results showed that spatial pattern of *** was clumped pattern under large and small scale at different habitats which were extremely unstable,that was,the surface substrate frequently shifts,the soil water-content was highly variable and the site did not permit the growth of any other plant *** of the elongation of its fine roots,*** were well adapted to dry sandy soil and able to penetrate deep soil layers containing *** biomass and the pod numbers increased under conditions where enough water was *** A,squarrosum had many branches which divaricating place was lower,strong mechanism intensity and strong root system to endure wind erosion in winter and spring seasons,so it could reduce wind velocity *** individual reduced wind velocity obviously,so sands carried by wind current to pileup and form the sandy *** curve of the sandy tongue to the physical volume of *** was conic that equation was y=0.0008x-0.2117x+ 43.509（R=0.964）.Highest an