以青藏高原高寒草甸禾草、矮嵩草和小嵩草的重要值及斑块变化为对象，研究其在嵩草草甸退化和恢复过程中的变化规律。结果表明，退化中的嵩草草甸小嵩草重要值显著高于矮嵩草和禾草，样带调查显示在小嵩草样带矮嵩草盖度急剧降低，黑斑盖度增加近一倍，小嵩草斑块分布普遍；重牧小嵩草草甸小嵩草成为优势种，重要值显著高于矮嵩草和禾草（ P ＜0.05），黑斑面积增大，塌陷增多，矮嵩草斑块出现几率小；恢复中的小嵩草草甸禾草重要值增大，矮嵩草恢复慢，恢复斑块上禾草成为优势种，小嵩草斑块接近消失，黑斑和秃斑面积急剧缩小，植被盖度增加；恢复较好的草甸禾草成为样地的优势种，矮嵩草和小嵩草的重要值低（零星斑块分布），没有黑斑和秃斑出现。高寒草甸退化引起优势植物更替，地表黑斑和秃斑严重，封育和减牧措施能够有效恢复退化的草甸。

The present study analyzed the plant biomass, soil physical and chemical properties and soil microbial quantities of different community composition using quadrat sampling method. The results showed the aboveground biomass of Salix paraqplesia alpine shrubs meadow was significantly higher (P

利用样方法，分析了青藏高原不同植被类型生物量、土壤理化性状及土壤微生物数量。结果表明，高山柳（Salix paraqplesia）灌丛草甸的地上生物量显著高于圆穗蓼（Polygonum macrophyllum）草甸、藏嵩草（Kobresia tibetica）草甸和小嵩草（K. pygmaea）草甸（P≤0.05），而藏嵩草草甸的地下生物量显著高于小嵩草草甸、高山柳灌丛草甸和圆穗蓼草甸（P≤0.05）。藏嵩草草甸的土壤有机质、土壤全氮依次高于圆穗蓼草甸、高山柳灌丛草甸和小嵩草草甸。相反，土壤养分居于中间水平，土壤含水量较低的圆穗蓼草甸土壤微生物数量则最多。

The patchiness and persistence of plant communities represent grassland responses to outside disturbance, 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 abundance of a single species, with mini-patch areas ranging from 0.5 m 2 to 100 m 2 in an alpine meadow (not including 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 within 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 phosphorus) 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 patches 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 total nitrogen, available nitrogen, and available phosphorus than for other soil properties in patches in the meadows with moderate burrow density. The contents and spatial heterogeneity of soil total nitrogen, available nitrogen, and available phosphorus were more sensitive than the responses of vegetation succession to plateau pika activity. Therefore, it is very important that the supply of total nitrogen and available nutrients are maintained to retain the stability of the alpine meadow ecosystem.

植物群落的斑块化与维持是草地对外界干扰的响应,也是植物群落及其生物多样性持续发展的基础。分析了3个不同鼠洞数量梯度下斑块种类、数量、面积的变化和中度鼠洞数下5种主要斑块植物群落的结构及其土壤性质。结果表明,在中度鼠洞数下,斑块的种类和总数量最高;斑块的总面积随鼠害的加重呈增加趋势;从中度到重度梯度上,鹅绒委陵菜、黄帚橐吾和草玉梅斑块的数量和面积都增加,且面积增大剧烈,乳白香青和火绒草等斑块的数量和面积都减小,具有消失的趋势;在重度鼠洞数量下草地微斑块表现为由少数起主导作用的斑块组成,斑块格局变的较为简单。斑块中单一物种生物量的变异性增加是斑块最主要的特征,这种单一物种的大量繁殖影响着斑块中植物的功能群结构和物种的多度,从而通过不同形式对干扰产生缓冲作用。植物群落的斑块化影响着土壤的异质性,对不同斑块土壤性质进行主成分分析,除乳白香青和基质斑块,其余4种斑块土壤都具有较低的全氮、碱解氮、速效磷,且不同斑块间土壤全氮、碱解氮和速效磷的变异系数都较高,可见,土壤全氮、碱解氮和速效磷的含量以及空间异质性在响应植被的演替上较敏感,因此,高寒草甸生态系统中维持全氮和速效养分资源的供应对维持生态系统的稳定具有重要的意义。

To provide foundation for researches on vegetation succession and mechanism of heterogeneity formation in alpine meadow, changes of vegetation composition, forage nutrients, plant importance value, plant niche breadth and plant niche overlap in Tibet Plateau alpine meadow with yak dung depositing were quantitative analyzed in this study. The results showed that, yak dung deposition significantly increased herbage biomass, green matter weight, plant height, coverage and K content of herbage, but had no significant influence on dead matter biomass and number of species. For dominant species, yak dung deposition decreased importance values of Stipa purpurea, Koeleria cristatav and Kobresia humilis , increased niche breadth values of these three species, and increased importance values of K.capillifolia and Agropyron cristatum . So yak dung deposition made these dominant species become to generalization species. For accompanying species, yak dung deposition decreased importance value of S.aliena , increased importance vale of S.krylovii , and decreased importance value and niche breadth value of Polygonum viviparum . For few species, yak dung deposition increased niche breadth values of Elymus nutans, Aremisia Smithii, A. capillaries, A. frigida, Allium sikkimense and Stellera chamaejasme . Beside, yak dung increased the whole niche overlap value of plants, increased species pairs, whose overlap values were >0.85, by increased 13.8%, while decreased species pairs, whose overlap values were<0.45, by 42.9%. In a word, yak dung deposition increased the proportion of grasses, and promoted the meadow transformation from sedge+grasses community to grasses community or grasses+sedges community.

本研究定量分析了青藏高原高寒草甸牦牛粪斑与对照处植被构成、牧草养分、植物种重要值、生态位宽度和生态位重叠值的变化,为高寒草甸植被演替和异质性形成机制的揭示提供科学依据。结果表明,牦牛粪沉积增加植物总生物量和活体质量,使草层高度、盖度和牧草K含量增加,而对死物质质量和物种数无影响。粪沉积降低优势植物紫花针茅( Stipa purpurea)、艹洽草(Koeleria cristata)和矮嵩草(Kobresia humilis)的重要值,增加其生态位宽度,并提高线叶嵩草(Kobresia capillifolia)和扁穗冰草(Agropyron cristatum)的重要值,使优势种植物更倾向于泛化种。粪沉积使伴生种异针茅(S.aliena)的重要值降低,西北针茅(S.krylovii)的重要值增加,珠芽蓼(Polygonum viviparum)的重要值和生态位宽度均降低,使少量种垂穗披碱草(Elymus nutans)、球花蒿(Artemsia pratensis)、茵陈蒿(A.capillaries)、冷蒿(A.frigida)、高山韭(Allium sikkimense)和狼毒(Stellera chamaejasme )的生态位宽度增加。粪沉积使草地植物的整体生态位重叠值增大,使生态位重叠值>0.85的种对增加13.8%,生态位重叠值<0.45的种对降低42.9%。总之,粪沉积使草地禾草比例增加,促进高寒草甸草地由莎草+禾草群落向禾草群落或禾草+莎草群落转化。

By visual observing, qudrat measuring and food analyzing before and after foraging, the food niche differentiation between livestock (yak and Tibetan sheep) and rodents (plateau pika and plateau zokor) was investigated in Gannan alpine meadow. The results showed that foodspectrum of rodents and domestic animals were different. Tibetan sheep and yaks mainly feed grasses and sedges, however, pika had broad food spectrum and zokor mainly feed the plants with taproots, rhizome, bulbs and earthnut. The food niche width, species diversity and evenness of livestock were significantly higher than those of rodents. The overlap of food niche between Tibetan sheep and yak was the highest, that between pika and tibetan sheep followed and that between zokor and Tibetan sheep was lowest. These results indicated that the food niche differentiation between rodents and livestock was larger because of the limited adverse effects of food competition on livestock.

通过肉眼观测、样方测定和采食前后对比分析的方法，对高寒草甸主要家畜[牦牛(Bos grunniens)和藏羊(Ovis aries thibetana）]和鼠类动物[高原鼠兔（Ochotona curzoniae）和高原鼢鼠(Myospalax baileyi)]的食物生态位分异进行了研究。结果表明，鼠类与家畜的食物资源谱存在较大差异，禾草和莎草是藏羊和牦牛食物结构的主体，而高原鼠兔的食谱较为宽泛，高原鼢鼠则主要涉及具有发达轴根、根茎、球茎和块根类植物。家畜的食物生态位宽度、物种多样性和利用均匀度均显著高于鼠类。食物生态位重叠度以藏羊和牦牛最高，其次为高原鼠兔和藏羊，重叠度最低的是高原鼢鼠和藏羊。由此可见，鼠类与家畜的食物生态位分异较大，因食物竞争而对家畜构成的不利影响较为有限。

对高寒草甸珠芽蓼中几种抗氧化物质含量的季节变化测定发现,珠芽蓼叶片内抗坏血酸、超氧阴离子自由基的相对含量、超氧化物歧化酶的活性以及紫外辐射吸收色素在5月至8月间呈现"拱型"曲线变化,不同物质分别以6、7月份最高,分别与海北站地区的太阳辐射呈现一定的相关性.

珠芽蓼是高原上广泛生长的具有胎生现象的植物，并且是冬虫夏草寄主昆虫的主要饲料植物。通过野外观察、石蜡切片、实验室培养等方法对珠芽蓼的花器、果实、种子和珠芽形态，开花、结实和结种过程，珠芽繁殖特性等多方面进行研究，从珠芽的形态和发育过程揭示胎生繁殖机理，筛选珠芽萌发生长的适宜条件。为完善胎生植物生物学研究，珠芽蓼资源的开发利用提供支持。研究得到以下结果： 1．珠芽蓼的花和开花特性 （1）珠芽蓼的花序上着生花和珠芽，根据花序上着生花和珠芽数的多少分为三类：全珠芽、少花多珠芽、半花半珠芽。根据花序上每个苞片内花朵、珠芽情况...

[目的]研究喀斯特山地草地植物群落优势种植物的种类、数量以及 群落特征,为喀斯特山地草地植被恢复提供支持.[方法]采用标准样地调查法,对不同海拔、坡向的植物群落数量特征展开研究.[结果]不同海拔高度中禾本科 植物重要值和优势度最高,但其重要值和优势度随样点海拔的升高呈现出下降趋势；优势种数目随着海拔升高呈现出增加趋势.[结论]海拔是影响喀斯特山地草地 植物群落结构的主要因素.

应用2×2列联表的χ2检验和Spearman秩相关系数研究了五台山蓝花棘豆群落(Oxytropiscoeruleacommunity)的种间关系,分别测定了18种植物,共153个种对的种间关联(或相关)。结果表明,χ2检验仅有6个种对为显著或极显著正(或负)关联,而相关系数表明有10个种对呈显著正相关,8个种对呈显著负相关。整体来看,大多数种群之间关系松散。种群之间正关联或正相关主要是由于它们具有相近的生物学特性,对生境的需求相似;而种对间的负关联和负相关,则主要是由于它们具有不同的生物学特性,对生境具有不同的生态适应性或相互竞争所致。

采用x2检验、Ochiai关联指数、Pearson相关分析和Spearman秩相关分析法对北沟林场天然次生林11种乔木的种间联结和相关性进行了研 究,结果表明:所有种对中,呈显著相关和极显著相关的种对数所占比例较少,多数种对间关联程度未达到显著水平,说明林场多数乔木树种间关系不紧密,未形成 明显的总体联结性,群落处于相对稳定状态；种间关系分析中,Spearman秩相关分析结果比x2检验、Ochiai关联度和pearson相关分析的结 果灵敏度要高；依照分析结果,结合植物种群的生物学和生态适应特征,将北沟林场天然次生林群落中11种乔木树种划分为3个生态种组,同一生态种组内物种资 源利用方式和生态要求相似,联结紧密,而不同组间联结较为松散.

Based on data obtained from field investigations , this paper aims to analyze the inter-specific relationships of desert riparian forest plant communities, assess the influence of different quadrat sizes on inter-specific associations, discuss what is an appropriate quadrat size for best results, and present the relationships among populations in desert riparian forests in the middle and lower reaches of the Tarim River using Fisher's exact test. The results showed that 16 species noted in 21 sampling sites formed the principal community of the desert riparian forest. The vertical structure of the forest consisted of a tree layer, shrub layer and herb layer. It was found that 4 sampling sites had 3 layers, 10 had 2 layers and 7 had 1 layer. There were 120 species pairs formed by 16 species in 210 quadrats among which 17 species pairs showed significant and very significant inter-specific associations, accounting for 14.2% of total species pairs. Thirteen species pairs were positively correlated and four species pairs were negatively correlated. The size of the quadrat influenced the inter-specific associations among species pairs, but the most suitable quadrat size varied among species and sampling sites. A quadrat from 8 m×8　m to 30　m×30　m may be the most suitable size for analysis of inter-specific associations of desert riparian forest communities in Tarim River basin. Different species pairs had different minimum quadrat sizes. There was spatial variance in the interaction between different populations of the desert riparian forest. Different patterns and relationships of inter-specific associations were found as the size of the quadrat increased. Generally, four types of changes in species associations were observed with changing quadrat size. For the first type, the correlative significance of species pairs changed from high to low and then to high as the quadrat size changed from the minimum size of 2 m×2 m to the maximum size of 32　m×64　m. These species pairs accounted for 17.6% of the total species pairs. In the second type of variation, the correlative significance of species pairs changed from low to high and then to low with an increase in quadrat size. These species pairs accounted for 41.2% of the total. For the third type, the significant and very significant inter-specific associations occurred in quadrats that ranged in size from 8 m×16 m to 32 m×64 m. The correlative significance of species pairs changed from low to high, and if the quadrat size continued to increase, new relationships would emerge. These species pairs accounted for 29.4% of the total. For the forth type, the significant and very significant inter-specific associations changed from low to high and then from low to high again as the quadrat size continued to increase. These species pairs accounted for 11.8% of the total. Species associations among shrub-herb and herb-herb pairs were more numerous in 17 inter-specific associations, accounting for 76.5% of the total. Species associations between Populus euphratica and arbor and shrub-shrub were distributed independently of each other. Even if inter-specific associations among species-pairs appeared, they were usually negative correlations. Most species-pairs, which were between arbor and herb-shrub and herb-herb, typically had positive correlations.

采用2×2列联表，应用Fisher精确检验法研究了新疆塔里木河中下游荒漠河岸林群落种间关系，测定了16种植物、共120个种对的种间联结性。研究结果表明：1) 120个种对中有17个种对分别在不同的样方尺度中表现出显著或极显著的种间联结，约占总数的14.2%；其中13个种对为正关联，4个种对为负关联；2) 不同取样面积对种间联结性分析的有效性有影响，不同种对表现出种间联结的最小样方尺度不同；3）随着样方面积的增大，各种对自有不同的种间联结变化规律，可归纳为4种类型；4）17个具种间联结的种对以灌木-草本和草本-草本的种对居多，占总数的76.5%；主要乔木树种胡杨（Populus euphratica）与灌木之间、灌木和灌木之间趋向独立分布。

The contents of total polyphenols and flavonoids and their influence on the antioxidant activity of 12 alpine plants sampled from Qilianshan Mountains were investigated.The determining was focused on the shoots and leaf of the targeted plants by using methods of The Folin-Ciocalteu method and aluminum salt colour reaction.The total antioxidant capacity was estimated by ABTS and FRAP methods.The results showed that Potentilla fruticosa,Salix oritrepha,Spiraea alpina,Hippophae thibetana and Polygonum viviparum had high levels of total polyphenols,flavonoids and antioxidant capacity.The highest total polyphenols content was found in the S.oritrepha ,it was as high as 19.58%.The total flavonoids content of S.alpina was the highest,up to 13.23%.While the H.thibetana showed a strongest antioxidant capacity of 49.58 mmol/L(FeSO 4 ) by FRAP measurement,but P.fruticosa had the strongest antioxidant capacity for 32.46 mmol/L(Trolox) by ABTS determination.Total polyphenols,flavonoids and total antioxidant capacity in the FRAP method had extremely significant correlation;the relative coefficient reached a value of 0.887 1 and 0.915 7,respectively.The analysis about 12 alpine plants showed that the higher total polyphenols and flavonoids,the stronger total antioxidant capacity.

采用Folin-Ciocalteu法和铝盐显色法对祁连山东段12种高寒植物（灌木嫩枝和草本植物叶片）进行总酚、黄酮含量的测定，并用FRAP法和ABTS法测定其总抗氧化能力。结果表明:(1)金露梅、山生柳、高山绣线菊、西藏沙棘、珠芽蓼的总酚和总黄酮含量较高且总抗氧化能力较强，其中山生柳的总酚含量最高为19.58%，高山绣线菊的黄酮含量最高为13.23%。（2）采用FRAP法测得西藏沙棘的抗氧化能力最强为49.58 mmol/L,而用ABTS法测得金露梅的抗氧化能力最强为32.46 mmol/L。（3）总酚、总黄酮与总抗氧化能力(FRAP法)具有极显著的相关性(相关系数分别为0.887 1和0.915 7)。分析认为，12种高寒植物的植株体内总酚和总黄酮含量越高，其抗氧化能力越强。