Health sequence analysis of a plant community in the sand-accumulation belt along the oasis fringe in Minqin, China

With desert control effort in more than 60 years in Hexi Corridor of Gansu Province,sand-accumulation belts have taken into form along the oasis fringe. Among which,the sand-accumulation belt at the fringe of Minqin oasis is relatively typical and complete. The vegetation on the sand-accumulation belts is the important factor not only for the formation,but also for the stability maintaining of the belts. To some sense,the healthy vegetation on the belts is decisive to the stability of the belts. To analyze the healthy status of the vegetation on the sand-accumulation belt,we designed 11equal-interval sample lines on the belt along the fringe of Minqin oasis. Vegetation on more than 60 plots was investigated and the healthy sequence of plant communities was analyzed. The result showed that the vegetation on the sand-accumulation belt at the fringe of Minqin Oasis was generally unhealthy. However,the vegetation on the belt with artificial sand-fixation was healthier than that on the belt with natural shrub nebkhas,and the vegetation on the belt with mixed arbor and shrub is the least healthy. The dominant species on the sand-accumulation belt downstream Minqin Oasis,Tamarix laxa,was dead or seriously unhealthy. This means that the sand-accumulation belt is under potential risk of wind erosion and activation. As farmland has been abandoned,efforts should be made to protect the farmland windbreak and the sand-accumulation belts.