Analysis on Interspecific Relationship of the Dominant Plant Species in the Ebinur Lake Wetland Nature Reserve, Xinjiang: Analysis on Interspecific Relationship of the Dominant Plant Species in the Ebinur Lake Wetland Nature Reserve, Xinjiang

Abstract

According to the classification of the typical plant communities in the Ebinur Lake Wetland Nature Reserve,45 sample plots of 10 m×10 m were delimited around the reserve at the Dongdaqiao and Yaziwan management stations to record the quantitative community features including the species,abundance,height,stem diameter and crown diameter as well as the elevation,latitude,longitude,circumstance,geographical features and terrain of each sample plot during the period from June to September 2007.The χ2-test,contingency table,VR,Ochiai association index,Pearson's correlation coefficient and Spearman's correlation coefficient are used to study the interspecific relationships among the 25 main species in the typical communities in the Ebinur Lake Wetland Nature Reserve.The results are as follows:(1) The species of vegetation in the typical communities in the reserve are mainly composed of the families of Salicaceae,Tamaricaceae,Gramineae,Chenopodiaceae and Fabaceae,the species composition is poor,and 28 species samples were collected in the sample plots.The important value of Populus euphratica is the highest,and then it is followed by Halostachys caspica,Halocnemum strobilaceum,Aeluropus pungens and Glycyrrhiza uralensis.P.euphratica is the primary species in the study area and also the dominant one of the arbor layer,while H.strobilaceum,A.pungens and G.uralensis are separately the dominant plants of the shrub layer and herbage layer;(2) The total associations among all the species in the Ebinur Lake Wetland Nature Reserve are unremarkable negatively significant,and the unremarkable couples of species account for the highest proportion;the plant communities tend to grow independently.The results of χ2-test with contingency table also reveal that the associations between most of the pairs in the communities are remotely related,if so,the pairs of positive association will overweigh negative one,which shows that there is more mutual contribution among the associated species,and one's existence benefits another although the effect is unremarkable.There are more remarkably relative coefficients among the herbages,such as A.pungens,G.uralensis,Asparagus persicus,Alhagi sparsifolia and the other species than that of the arbors and shrubs,such as Tamarix ramosissima,H.strobilaceum,Reaumuria soogarica,Haloxylon ammodendron,P.euphratica,etc.The fact that the herbages are widely distributed over the investigated area indicates that these plants have a higher level of maturity and coexist with other species.The arbors and shrubs are comparatively more competitive than other species in making use of special resources.Based on the study of affinity in the Ebinur Lake Wetland Nature Reserve,Spearman's correlation coefficient is more sensitive to the affinity among species and higher compared with Pearson's correlation coefficient.Ochiai association indexes and the χ2-test with contingency table are consistent with each other;(3) Species with similar nature in the communities can be integrated as the biological groups,and they in the same group have more mutual associations and relativity and are in accordance with each other in adaptation to environment.According to the results of the Spearman's constellation diagram and χ2-test among the species,25 main species in the Ebinur Lake Wetland Nature Reserve can be divided into four biological groups.The first group is constituted by P.euphratica and H.persicum,P.euphratica is the constructive species and play a decisive role in this community,H.persicum is the co-constructive one.Both of them provide with a higher value of the dominance index.The second group is composed of A.pungens,T.ramosissima,Suaeda microphylla,Halimodendron halodendron,Cynanchum sibiricum and H.caspica.All the species in the second group are drought-enduring and infertile-enduring,and their choice to habits is very large.And the third group is composed of H.ammodendron,H.strobilaceum,Karelinia caspicas and R.soogarica,most of these species grow mainly on saline land of lake bank.