Preliminary Study On The Ecological Characteristics Of Haloxylon Ammodendron Community In Mosowan District

Absract:The ecological characteristics of Haloxylon Ammodendron Community,includingthe traits of the flora composition,the species elements,community structure,populationdistribution patters and interspecies association were studies by both population Ecology andcommunity Ecology in the paper.The main results were as follows:1,The species category constituted to statistic totally has 38 species of higher plant belongingto 13 families,30 genera of the early spring in the study area.Among them,Chenophdiaceaeare the most dominant families.But the species category has 19 species of higher plantbelonging to 7 families,16 genara of Autumn in the study area. .Cruciferae are the mostdominant families.Most species have drought resistance ability including smallnanotree,shrubs,nanoshrubs,therophytes and ephemeral plant.Ephemeral plant is dominant inthe life form.2,The community stratification structure is simple.The physingnony of the community isdecided by the leaf form including a little of scale-leaf and micro-leaf,most of thenano-leaf ,orthophyll simply leaf ,entire leaf therophytes plant.All in all,the order of thespecies richness,diversity index,evenness index,ecological dominance of community:theherbage >shrub >the small arbor . The ecological dominance of the small arbor arehigher than the herbage and shrub community. the small arbor plant are dominant in theHaloxylon Ammodendron Community.3,The spatial patterns of Haloxylon Ammodendron Community are clump distribution whichis higer from the entire community. The spatial patterns are clump distribution from 0 the 15size. The spatial patterns of Haloxylon Ammodendron Community transform the clump torandom distribution from 15 to 20 size. The distribution are he random when sizes is higerthan 20.The age structure of the population isⅠ,Ⅱ,Ⅲand Ⅳgrade,which is clumpdistribution.But The clumpness of Ⅰgrade are is highest than the otherⅠgrade. Theclumpness of Ⅳgrad are obviously small, whose distribution are clump. Ⅴgrad are randomdistribution.4,The overall association were negatively associate from 1×2 ㎡to 4×8 ㎡level quadrats inthe early spring.With enlarging the area of the quadrats size,the overall associations of allspecies were not significant.Its were positively associate until area reach to 32×32 ㎡.Bymeans of χ2-test , 50 species pairs showed significant interspecific association,accountingfor 46.7% of total species pairs,among 105 species. 27 species-pairs were the greatlypositive association among,19 species-pairs were the significantly negative connection.Bymeans of Fisher exact test,42 species pairs showed significant interspecific association among105 species. 26 species-pairs were the greatly positive association among,11 species-pairswere the significantly negative connection.5,The interspecific association in the community show on the basis of the associationcoefficient and the minimal association area in the community.There was spatial variance inthe interaction between different population of Haloxylon AmmodendronCommunity.Different patterna and relationships of inter-specific associations were found asthe size of the quadrat increased.Generally,six type of changes in species associatipns areobserved with changing quadrat size.