Alpine meadow mainly locates in the Qinghai-Tibetan Plateau and other high altitude areas, and plays a vital role in maintaining the balance of the global ecosystem. Recently, the extensive degradation of alpine meadow has been caused by the global climate change and the interference of human activities, which has made these areas extremely important for further study. People have applied a few measures to restore the degraded grassland, however there was no quantitative mean that could evaluate the effectiveness of ecological restoration measures synthetically. For the scientific assessment of the effects of different ecological regulation measures on the degraded alpine meadow ecosystems, this research was conducted in Maqu alpine meadow in Gansu Province, northwestern China from May 2010 to December 2012. The VOR (vigor, organization, resilience) and CVOR (condition, vigor, organization, resilience) ecosystem health evaluation models were utilized to evaluate the health condition of the degraded grassland ecosystem after restoration, and the restoration measures included enclosure, ripping, organic material addition, reseeding and comprehensive measure, and the grazing was taken as the control. We implemented enclosure and slicing of the pasture vertically and horizontally with the plough as ripping, implemented enclosure, scarifying and fertilization in the pasture with sheep manure of 22.5 t/hm2 as organic material addition, and implemented enclosure and reseeding with Elymus nutans of 15 kg/hm2 as reseeding. And for grazing treatment we used the grazing pressure of about 2-2.5 yak/hm2. As for comprehensive measure, we combined the treatment of enclosure with the treatments of ripping, organic material addition and reseeding. For the calculation of evaluation model, we determined soil organic carbon content and gauged above-ground biomass, Shannon-Wiener species diversity index, biomass of functional groups and economic groups of all the grass under different regulation measures to further compute condition index (C), vigor index (V), organization index (O), and resilience index (R). We expected to find which ecological regulation measure was the most effective and contrasted 2 models to check the applicability. The results showed the CVOR health evaluation index was relatively more comprehensive than the VOR health evaluation index considering the importance of basic condition, which could more objectively reflect the additional specific soil nutrient status (organic or inorganic), and more quantitatively manifest the effects of restoration measures of grassland ecosystem, contributing to the specific formulation and the implementation of specific engineering management measures. According to the 2 models, the VOR index evaluation calculation results showed the effects of organic material input and comprehensive measure on recovery and rehabilitation of degraded grassland were more obvious than others, their health values rose by 5%-9% year by year simultaneously, and the value of grazing was lower than other measures significantly (P<0.05). The CVOR index evaluation calculation results showed the effect of comprehensive ecological restoration measure was superior to other single treatment measure and its value reached 0.917 that was significantly higher than others (P<0.05), while grazing led alpine meadow ecosystem to health “warning” level and its value went down to 0.572, which was lower than other measures significantly (P<0.05). The results manifested that the implementation of comprehensive measure in local degraded areas can achieve the purpose of saving the grassland ecosystem health comprehensively and quickly. But in practice due to the comprehensive measure cost is high, for selecting the optimum ecological recovery measure, it requires specific consideration of each measure’s dual benefits of economy and ecology so as to adjust the measures to local conditions.

We analyzed the selection of habitat by plateau pika in degraded alpine meadow in Maqu County through different grassland improvement measures including enclosure,reseeding,fertilization (organic)and cleavage to help reveal aspects of the ecology of plateau pika and to provide theoretical basis for ecologically based management of plateau pika.From May to July 2010,12 different grassland improvement measures were implemented.The density of active pika burrows was estimated using a stolen hole (mousehole)technique,and the selection of habitat by pika assessed.Compared with the control,the density of active pika burrows un-der different treatment measures was significantly reduced (P <0.05).All of the grassland improvement meas-ures,especially reseeding,decreased the density of active burrows.The relationship between active burrow density and community structure was analysed using correlation analysis and stepwise regression analysis;the density of active burrows was significantly,negatively correlated with grass layer height (P <0.05).This sug-gests that grass height is an important factor influencing the density of pika.Using multiple management con-trol factors including reseeding and fertilizer application promoted grass productivity,increasing grass layer height,decreasing active burrow densities (P <0.05).In alpine meadow areas of Maqu,different grassland improvement measures can effectively reduce the density of pika burrows,particularly those which increase the proportion of the grasses in the meadow.

The patchiness and persistence of plant communities represent grassland responses to outside disturb-ance,and are the basis of sustainable development of plant communities and biodiversity.The aim of this study was to understand the factors contributing to the maintenance and development of plant communities and the effects of patchiness on soil properties after a disturbance.The changes in the types,number,and areas of mini-patches in meadows were evaluated in meadows with a light,moderate,and heavy density of plateau pika (Ochotona curzoniae )burrows.The plant community structure and soil properties were evaluated for five types of patches in meadows with a moderate number of burrows.Some mini-patches were characterized by a high a-bundance of a single species,with mini-patch areas ranging from 0.5 m2 to 100 m2 in an alpine meadow (not in-cluding background patches).These types of patches were named according to the main plant species.We chose three approximately 1-hectare sample sites with different burrow densities;light,moderate,and heavy. Three quadrats (20 m×20 m)were placed randomly to determine the types,number,and area of patches with-in each site.We chose five types of patches from the three sample sites,and selected three typical patches for each type to determine the plant community structure and soil properties.Quadrat sampling (1 m×1 m)was used to determine basic plant traits (composition,height,cover degree,above-ground biomass of vegetation) and soil properties (organic carbon,pH,total nitrogen,available nitrogen,total phosphorus,available phos-phorus)in the patches.The meadows with moderate burrow density had the most types of patches and the greatest abundance of patches.The total area of patches tended to increase with greater deterioration caused by plateau pika.The number and areas of Potentilla anserine ,Ligularia virgaurea ,and Anemone rivularis pat-ches tended to increase,and their areas increased dramatically from the moderate to heavy burrow density.The number and areas of Anaphalis lacteal and Leontopodium japonicum patches tended to decrease,and these patches tend to disappear from as the burrow density increased from moderate to heavy.There were few main types of pasture mini-patches,and the pattern of patches was relatively simple under heavy burrow density.An abnormal increase in the biomass of a single species was the main characteristic of the patches.The expanding propagation of single species affected the structures of plant functional groups and species abundance,and thus, cushioned the effects of other types of disturbance.The results of the principal component analysis showed that the amounts of total nitrogen,available nitrogen,and available phosphorus in soil were lower in four types of patches than in A.lacteal patches and background patches.The coefficients of variation were higher for soil to-tal nitrogen,available nitrogen,and available phosphorus than for other soil properties in patches in the mead-ows with moderate burrow density.The contents and spatial heterogeneity of soil total nitrogen,available ni-trogen,and available phosphorus were more sensitive than the responses of vegetation succession to plateau pi-ka activity.Therefore,it is very important that the supply of total nitrogen and available nutrients are main-tained to retain the stability of the alpine meadow ecosystem.

以45份垂穗披碱草(Elymus nutans)野生种质为材料,利用主成分分析和聚类分析对其9个产量和品质性状进行综合评价,为今后高产优质品种的选育提供育种材料.结果显示:45份垂穗披碱草材料各性状都存在显著差异,其中干草产量变异系数最大为40.86％,中性洗涤纤维和酸性洗涤纤维变异系数较小,分别为2.43％和5.37％;相关性分析表明参试材料的各性状间存在着不同程度的联系,尤其产量与可溶性糖呈显著负相关,粗蛋白含量与株高、干物质含量等农艺性状呈显著负相关;主成分分析将9个性状转化成4个主成分,其累计贡献率达84.53％,可以代表原始指标的绝大部分信息;聚类分析将45份种质材料分成8类,各材料并没有严格按照种源地聚在一起,而是来自相同生境的材料先聚在了一起.根据主成分分析和聚类分析结果,筛选出高产材料P16,高糖材料P22,P23和P42,高蛋白材料P36,以及P30,P31,P38和P39四个综合表现较好的优异种质.

探索简单、快捷的获得草地单个物种及群落地上生物量资料的方法,可以为合理保护和利用草地资源提供重要技术支持.在传统的直接收获法测定草地地上生物量的基础上,结合物种的种群特点,利用与生物量密切相关的高度、盖度、密度等植被生态参数,建立了青藏高原东缘高寒草甸各植物种的最适地上生物量估测模型.其中禾叶嵩草、垂穗披碱草、高山韭等物种生物量最适模型为幂函数方程,其他物种最适模型除却长毛风毛菊是二次项方程外均为线性方程.这些模型拟合精度较高,经检验,单个物种生物量估测值与实际观测值之间的相关系数均＞0.9,且大部分平均相对误差＜10％.对于草地群落地上总生物量,估测值与实际观测值相关系数为0.965,各样方的相对误差大都＜10％,平均相对误差为5.672％,说明利用这些模型估算青藏高原东缘高寒草甸地上生物量切实可行.