The macrostructure and microstructure of the timber of Populus wenxianensis were observed,focusing on revealing its fiber properties.The results showed that the fiber content in the wood of the species reached to 63 %,the fiber length was 1 209 μm,the ratio of length to width of the fiber was 57.4∶1,and the ratio of its wall to cavity was 0.293∶1.Therefore,the tree species could be used as one of high-quality materials for papermaking.

Based on the timber experiment of Wenxian Poplar,the paper researched its 9 kinds of common physic mechanics characters and evaluated its timber character index.The result shows that:its timber growth rate is greater;the intensities of pressure resistant,crook resistant and cut resistant are all lower,the elasticity modulus of crook resistant and shock toughness are moderate.The contrast analysis shows that,the timber physic mechanics character is similar with the other species of Populus.The main orientation of timber utilization is pointed out.

The factors causing grassland in Maqu County of Gansu Province were analyzed and it could be concluded that both natural factors and human factors were the crucial issues.The overgrazing and rodent/pest damage were very severe after degradation.It was suggested that the stocking rate should be determined on the base of carrying capacity and the enclosure,re-seeding and rodent/pest control should be carried out in order to control the grassland degradation.