The Mid-domain Effect Of Plant Diversity In The Southern Of Gurbantonggut Desert

Xinjiang is the most serious desertification hazard region, The desert vegetation can stabilizesand surface and improve desert ecosystem. The research of composition and distribution of plantdiversity for the vegetation has important significance to protection measures and effectiveengineering, reduce the harm of desert to the oasis agriculture and people’s life.The Mid-domain effect (MED) hypothesis states that if the ranges of the species arerandomly distributed within a bounded domain then mo re ranges will overlap near the middle ofthe domain than at the edges, and thus decreasing species richness will be observed from themid-domain to the edges. Many studies have shown that the MDE is an important mechanismaffecting geographic richness pattern. which is the basis of biodiversity conservation, but lessresearch on desert plants diversity and validation.In this study, we had the case study in the famous desert in the temperate zone of the world,Gurbantunggut Desert, which concentrations of plant distribution, we analyzed the Mid-domaincharacteristics of desert plant diversity, from the regional characteristics of plant diversitydistribution and Species Pools hypothesis to study the reasons of formation mechanism with theMid-domain effect, and we also studied the sampling rate of plant diversity in order to improve theefficiency and safety of investigation. The results show that:(1) Mid-domain feature of plant diversity in Gurbantonggut desert is not obvious. The patternof species richness and density in latitude and longitude direction into different forms.(2) Three transects with different α-diversity, from big to small, respectively is the margin ofthe oasis transect> desert highway transect> desert hinterland transect; transects along with theincrease of longitude from the west to the east, between the belt and belt species similarity andalternative characteristics are inconsistent, which play a decisive role terrain and precipitation.Species analysis found that the desert highway transect with most species belong to the ephemeralplant, the transect with margin of the oasis is given priority to with perennial herb and shrubcommunities, and desert hinterland transect between the two.(3) According to the type of habitat differences, we divided the desert into fiveregions,Partition one to partition four have high species richness, species similarity betweenpartitions and alternative characteristics are basically the same, and partition five are severe salinaarea partition, plant richness is low, the area with the rest of the four small species similaritybetween partitions, and each alternative is stronger; The species composition of five partitionbetween the bigger difference.Combined hypothesis of species pool, we analyzed the ancient plantspecies, such as the quinoa, artemisia, ephedra and other subjects, found that the regionalenvironmental differentiation produced a significant impact on the distribution of original species.(4) Biodiversity field investigation is a hard work, how to improve the effectiveness ofinvestigations is the premise of the diversity, especially in the harsh environment to reduce the impact on the safety significance. This study based on the change of scale in species diversity,with Delphi software ordering plots sequences, obtained24-150curves to calculatethe range ofcritical sampling area in different percentages(60%,70%,95%), quantitative analysis the worth ofworkload with critical sampling area of biodiversity surveys. we also summarized thecharacteristics of species diversity and the efficient sampling method in different regions of thedesert.(5) Comprehensive these results showed that the reason of Mid-domain feature of plantdiversity in Gurbantonggut desert is not obvious is species diversity under the influence of theoasis micro-climate in the weft direction; In the meridional direction, desert altitude increasedgradually from west to east, the precipitation under the altitude is the direct cause to formate thispattern. Plus this study area is belong to small scale, The boundary effect is not big.