玉树州境内草原毛虫种群分布及其对生境草场植被的影响

草原毛虫Gynaephora qinghaiensis是分布在我国青藏高原高寒牧区的一种重要害虫，对高寒草甸植被破坏相当严重。为调查青藏高原高寒牧区草场草原毛虫的分布与危害情况，本研究在青海省玉树州的高寒牧区布设了10个调查样地，连续5年（2015-2019年）采用随机抽样的方法调查了草原毛虫种群密度，并于2016年同步调查了草原毛虫生境植被指数，并对2016年不同调查样地的草原毛虫种群密度与生境植被指数之间的相关关系进行了分析。调查结果显示，10个调查样地的草原毛虫种群密度在1.0~200.6 头/m^2之间，具有聚集性分布的特点，集中分布在治多草原、嘉塘草原和隆宝草原。根据高寒草甸草原毛虫危害等级划分标准，30%调查样地达到重度、极重度危害等级。相关分析结果显示，草原毛虫种群密度与植被总盖度之间呈极显著的负相关关系（P<0.01），表明随着草原毛虫种群密度的增大，草甸植被总盖度总体呈逐渐减小的趋势。总之，玉树州高寒牧区草场草原毛虫种群分布相对集中，密度较高，对草场植被危害严重，需及时采取有效措施予以治理。本研究对草原毛虫种群分布及其生境植被展开的基础调查工作可为草原毛虫灾害的预测预报以及草原毛虫的防控提供科学的基础数据，对保护青藏高原高寒牧区草场生态环境具有重要的意义。

Distribution of Gynaephora qinghaiensis population and its effect on habitat grassland vegetation in Yushu Prefecture

Gynaephora qinghaiensis is one of the most important pests in the alpine pastoral areas of Qinghai-Tibet Plateau in China, which damages seriously the alpine meadow vegetation. In order to investigate the distribution and damage of G. qinghaiensis from the grassland in the alpine pastoral area of Qinghai-Tibet Plateau, in this study, 10 sample plots were set up in the alpine pastoral area of Yushu Prefecture, Qinghai Province. Population density of G. qinghaiensis was investigated by random sampling method for five consecutive years (2015-2019), and habitat vegetation index of G. qinghaiensis was investigated simultaneously in 2016. In addition, the correlation between density of G. qinghaiensis population and habitat vegetation index in different sample plots in 2016 was analyzed. The results showed that population density of G. qinghaiensis in the grassland of 10 sample plots ranged from 1.0~200.6/m^2, showing the characteristics of aggregation distribution, and concentrated in Zhiduo, Jiatang and Longbao grassland. According to the classification standard of caterpillar hazard in alpine meadow grassland, 30% of the sample plots reached the level of severe or extremely severe hazard. The results of correlation analysis showed that there was a significant negative correlation between population density of G. qinghaiensis and total vegetation coverage (P<0.01), indicating that with the increase of population density, total vegetation coverage of the meadow was gradually decreasing. In conclusion, population distribution of G. qinghaiensis in grassland was relatively concentrated and its density was relatively high in the alpine pastoral area of Yushu Prefecture, which caused serious harm to grassland vegetation and required timely and effective measures to control it. The basic investigation on the population distribution and habitat vegetation of G. qinghaiensis in the grassland in this study could provide scientific basic data for prediction of G. qinghaiensis disaster in the grassland as well as prevention and control of G. qinghaiensis in the grassland, which was of great significance for the protection of the ecological environment of the grassland in the alpine pastoral area of the Qinghai-Tibet Plateau.