A Preliminary Study Of Cutting On The Plant Diversity Of Mountain Meadow Around Sayram Lake

Sayram Lake with its magical and beautiful natural scenery is famous at home and abroad,the water area of 458 km2, with an altitude of 2073 m, it is the largest and the highest altitude as a cold lake in Xinjiang. Every summer, the colourful beauty attracts tourists from all over the world,it is a 4 A level scenic tourist area of Xinjiang, it also be worthy of the name of National Wetland Park and national key scenic spots. In recent years, due to the unreasonable utilization and excessive exploitation of natural grassland, the Sayram Lake area appeared different degree of degradation, mainly for the decline of grassland productivity, vegetation secondary succession,etc.In this paper, as an object of study in Alchemilla tianshanica, grasses, Miscellaneous forbs type of mountain meadow on the west side of Sayram Lake, using the method of combining field investigation and indoor analysis, study on the influence of cutting on the community characteristics, diversity and regeneration speed at mountain meadow around Sayram Lake by alpha species diversity measure, Independent-Samples T Test and Spearman Correlation Analysis.To determine the rational utilization time and the theoretical stocking numbers of grasslands,provide scientific basis for the rational utilization and sustainable development of grassland around Sayram Lake. The main results are as follows:1. The effects of cutting on the A. tianshanica, grasses, Miscellaneous forbs type of mountain meadow only show the significant difference in aboveground biomass(P<0.05), but no significant effects on species diversity. Different economic group(rhizome-bunch grass, small leguminous,small sedge herbs, miscellaneous forbs) of plant after cutting in height, aboveground biomass and composition ratio are changed. The effects of cutting on Margalef index and Shannon-Wiener index with aboveground biomass was significantly correlation, but on Simpson index and Pielou index showed a very weak correlation; the overall performance of the three results, the positive correlation, negative correlation and no correlation.2. The growth(regeneration) rate of mountain meadow has three forms, namely single peak type, two peak type and three peak type. The cutting has certain influence on the size, time and frequency of peak. No cutting processing, Polygonum viviparum, Geranium pratense showed a single peak curve, A. tianshanica, Carex sp. showed two peak curve, and the grasses appeared three peak curve. In the same time(June 3rd) after cutting process, 5 plants all showed two peak curve. After cutting process, the regeneration rate of 15 d are higher than the speed of 30 d, the regeneration rate of grass were significantly greater than A. tianshanica, P. viviparum, G. pretense and Carex sp. in different periods, beginning from the mid to late August, grass growth is basically at a standstill.3. The early growth of grass is mainly concentrated in the green future, from June to early July, the absolute growth rate(AGR) > 0, the aboveground biomass has been increasing;Beginning mid to late July, AGR < 0, it’s the declining growth stage. Inside and outside the fence of the fresh yield was maximum in mid of July, the production in the fence is about 3 times outside the fence production; Ratio of dry to fresh weight in June 3rd and August 1st remained at between 30%-40%, then began to increase, plant water content less, it’s suitable for grass field.4. Compare theoretical capacity number of mountain meadow under different contrast, thefresh go down 7.87% in 2014 than in 2013, but the hay go up 39.39%. Using all year, the fresh theory of carrying capacity in 2014 is increase of 8.70% than 2013, hay fall 27.78%, using at seasonal pasture, the fresh theory carrying capacity in 2014 is increase of 12.5% than 2013, hay fall 23.08%, it showed that the grass theory carrying capacity of fresh in 2014 is weak than 2013,but the hay is stronger.