This paper studied the effect of grazing on biomass formation dynamics of Leymus chinensis at population level in the northeastern China grassland. The results show that the assimilation system standing biomass (ASSB), unassimilation system standing biomass (UASSB),litter accumulation, living rhizome biomass (LRB) and dead rhizome biomass (DRB) were decreased significantly with increasing grazing intensity. At heavily grazing stage, they were respectively 48.6,49.4,41.3 and 51.4% of those at lightly grazing stage. The same seasonal variation tendency was found between ASSB and UASSR, and between LRB and DRB.

在种群水平上研究了放牧对东北草原羊草草地羊草种群生物量形成动态的影响.结果表明,随放牧强度增加,羊草种群地上同化系统和非同化系统现存量、凋落物积累量及地下活根茎量和死根茎量均显著下降.重度放牧阶段,羊草种群地上同化系统、非同化系统现存量分别为轻牧阶段的48.6%和49.4%;地下活根茎量和死根茎量分别为轻牧阶段的41.3%和51.4%.同时地上同化系统与非同化系统间及地下活根茎量与死根茎量间具有相同的季节变化趋势.

From March to October 2009, a field survey was conducted on the darkling beetle community structure and related environmental factors in the desert grasslands with different vegetation cover and human disturbance intensity in Sidunzi of Yanchi, Ningxia, China. By using diversity index and canonical correspondence analysis (CCA), the relationships between the beetle community structure and related environmental factors were analyzed. A total of 5431 individuals were collected, belonging to 20 species and 10 genera. Blaps femoralis femoralis, Microdera kraatzi kraatzi , and Platyope mongolica were the dominant species, accounting for 47.30%, 39.90%, and 3.59% of the total, respectively. CCA explained 100% of the correlations between the beetle species and related environmental factors, suggesting that the occurrence of the beetle species had close relations to the changes of related environmental factors. Among the environmental factors, the Shannon diversity index of plant community (HP), plant biomass (BP), and soil water content (SW) affected the beetle species occurrence most. The occurrence frequency of Mantichorula semenowi, Anatolica amoenula, A. sternalis , and A. gravidula was negatively correlated with BP and plant coverage (CP), and that of B. gobiensis, Cyphogenia chinensis, Gonocephalum reticuluatum , and Crypticus rufipes was positively correlated with plant density (DP) and SW. The distribution of P. mongolica, M. kraatzi kraatzi, Scytosoma pygmaeum , and B. kiritshenkoi showed a positive correlation to HP, and that of Eumylada oberbergeri , B. femoralis femoralis, and B. davidea showed a positive correlation to BP and CP. There was a significant positive correlation ( r =0.943, P =0.005) between the beetle activity density and SW. The CCA ordination showed that the darkling beetles had different demands for multidimensional ecological resources in desert and semi-desert ecosystems.

2009年3—10月，对宁夏盐池四墩子不同植被类型和人工干扰强度的荒漠草地的拟步甲昆虫群落结构及其环境因子特征进行了调查, 采用多样性指数和典范对应分析(CCA)研究了昆虫群落与环境因子之间的相关性.共收集拟步甲10属20种，5431只，以弯齿琵甲、克小鳖甲和蒙古漠王占优势，分别占总数的47.30%、39.90%和3.59%.CCA分析表明：拟步甲与环境因子之间的相关性高达100%，提示盐池四墩子环境因子变化影响拟步甲的分布，植物群落多样性、植物生物量和土壤含水量对拟步甲昆虫群落的分布影响最大；从物种的分布状况看，谢氏宽漠王对环境最为敏感；小丽东鳖甲、宽突东鳖甲、尖尾东鳖甲、宽腹东鳖甲次之，与植物生物量、植被盖度呈负相关，戈壁琵甲、中华砚甲、网目土甲和淡红毛隐甲与植被密度和土壤含水量呈正相关，蒙古漠王、克小鳖甲、小皮鳖甲和异距琵甲与植物群落多样性呈正相关，奥氏真土甲、弯齿琵甲和达氏琵甲与植物生物量和植被盖度呈正相关；相关和回归分析结果也显示，拟步甲群落的活动密度与土壤含水量极显著正相关( r =0.943, P =0.005).同时，排序反映了拟步甲对生态环境的需求以及其在不同资源维上的生态分化现象.

Yanchi County in Ningxia Hui Autonomous Region, China is located in an area where the ecological environment is vulnerable, and it is a typical farmingpasturing ecotone in north China. In the county, the ecological conservation and environmental protection is paid great attention to at all levels since the grazingban policy was put into practice in Ningxia in 2003. In this study, the TM/ETM + and MODIS NDVI data were used to retrieve the ecological parameters and estimate the value of ecological assets in the county, and it was tried to provide an evidence for the ecological conservation, environmental protection and substantial development. The results show that the gross value of ecological assets was 1.62×10 8 , 2.15×10 8 and 2.70×10 8 yuan RMB in 2000, 2005 and 2010 respectively. In ecosystem service functions, the value proportion of soil and water conservation was the highest, in which the contribution of grasslands with the largest area was the highest in the land use/cover types. The value of ecological assets of rainfed farmland per unit area was the highest. The total value of ecological assets was in an increase trend in recent decade, especially in the loess hilly region, which demonstrated that the local ecological and environmental quality was trended to improvement under implementing the grazingban policy.

自2003年宁夏全境实行禁牧政策以来，处于农牧交错带的盐池县生态与环境变化受到广泛关注。利用2000年、2005年、2010年TM/ETM + 和MODIS NDVI数据，定量反演生态参数，计算3个时点的生态资产，评估禁牧政策的环境影响。结果表明：盐池县生态资产总值分别为1.62×10 8 、2.15×10 8 、2.70×10 8 元；生态系统服务功能中水土保持价值比重最大，其中贡献最大的土地利用/覆盖类型为占研究区总面积最大的草地；单位面积生态资产价值最高的为旱地，10 a间生态资产总体呈递增趋势，东南部黄土丘陵区增幅明显，说明过去10 a来禁牧政策有助于生态资产的增加，环境质量总体趋好。

Little is known about how desert-steppe systems contribute to the conservation of functionally important insect groups, including carabid beetles. Carabids are frequently used in terrestrial ecology on account of their well-known autecology, wide distribution, sensitivity to environmental changes. Many ecological studies have used diversity indices to assess the impact of environmental disturbance. In particular, ground beetles have been advocated as a good group for assessing disturbance. The aim of this study was to evaluate the influence of desert-steppe structure and type on carabid biodiversity. Habitat distribution and seasonal occurrence of carabid beetles were determined using pitfall traps from March to October in 2009 in a desert-steppe in Sidunzi of Yanchi, Ningxia, Northwestern China. Six transects differing in the vegetation and disturbance were selected so as to represent three habitat types: minimal disturbance ( Stipa bungeana grassland), moderately-disturbed ( Caragana microphylla shrubs grassland with Artemisia blepharolepis and Clycyrrhiza uralensis, fence grazing dominated by Caragana microphylla and Cynanchum komarovii ) and severely-disturbed desert-steppe ( Agropyron mongolicum grassland and mixed plantation with Artemisia scoparia and Clycyrrhiza uralensis ). During the field research, a total of 1318 carabid beetles were collected, belonging to 15 species and 9 genera. Of these beetles, four species dominated, i.e. Pterostichus gebleri , Pseudotaphoxnus mongolicus , Harpalus salinus and Pseudotaphoxenus brevipennis accounting for 33.08%, 19.73%, 15.94% and 8.04% of the total, respectively. Shannon diversity, species abundance, and evenness were significantly higher in the three transects of the moderately-disturbed desert-steppe than in the three other transects of the minimaly and severely-disturbed desert-steppes. Based on species composition and abundance, cluster analysis grouped carabid beetles according to the level of habitat disturbance. The carabid assemblage in Caragana microphylla shrubs was more similar to that of grassland with Artemisia blepharolepis and Clycyrrhiza uralensis and fence grazing dominated by Caragana microphylla and Cynanchum komarovii , that of Agropyron mongolicum grassland was similar to that of mixed plantation with Artemisia scoparia and Clycyrrhiza uralensis. Monthly catch of carabid abundance reached a peak in August, with monthly variation in species recorded between transects. Pterostichus gebleri peakedin August, Harpalus salinus in August and September, Pseudotaphoxenus brevipennis in May and August, Pseudotaphoxnus mongolicus from July to October. Canonical correspondence analysis (CCA) explained 100% of the correlation between species and five environmental variables, suggesting that the occurrence of many species was related to changes in ecological conditions. Among the five factors, the soil water content, the plant biomass and plant density were the major factors affecting on the composition and spatial distribution of carabid beetles in the desert steppe. According to the correlation analysis, we also found that some environmental characteristics, i.e., soil water content, plant biomass and plant density, significantly affected species composition and abundances. Additionally, soil water content was negatively correlated to Shannon diversity and evenness, and positively correlated to Simpson's dominance. Based on these results, we conclude that the appropriate pressure of human disturbance has significantly contributed to the reestablishment and maintenance of the diversity of carabid in the studied area.

采用巴氏罐诱法于2009年3月到10月对盐池四墩子3种不同类型荒漠草原的步甲物种组成、数量分布进行了系统调查,共获得步甲标本1318号,分属于9属15种,其中直角通缘步甲 Pterostichus gebleri 、蒙古伪葬步甲 Pseudotaphoxnus mongolicus 、径婪步甲 Harpalus salinus 和短翅伪葬步甲 Pseudotaphoxnus brevipennis 为优势种,个体数量分别占个体总数的33.08%、19.73%、15.94%和8.04%。多样性分析表明适度干扰荒漠草地的Shannon-Wiener多样性、丰富度和均匀度均高于低干扰和强干扰荒漠草地。群落相似性分析显示猪毛蒿和甘草混交带与围栏放牧带及柠条带有较高的相似性,蒙古冰草带和苜蓿与柠条混种带相似性较高。从时间动态上看,步甲群落的个体数量在8月份达到最高。4种优势种季节性变化分别是直角通缘步甲盛发期为8月,径婪步甲发生的高峰期为8、9月,短翅伪葬步甲在5月和8月,蒙古伪葬步甲7-10月个体数量均多;不同物种在不同类型荒漠草地出现的高峰期是不一致的。典范对应分析(CCA)分析表明土壤含水量是影响步甲分布的最重要环境因子,植物生物量和植被密度次之;土壤含水量与步甲的Shannon-Wiener多样性、均匀度显著负相关,与优势度呈显著正相关。

２００３年５－１０月在宁夏盐池荒漠草地进行了滩羊放牧强度试验，测定了宁夏滩羊采食量、采食率和草地产草量，以期确定草地适宜利用率，为解决宁夏草地全面禁牧后的重新利用提供依据。结果表明，在整个放牧季，草地现存量波动明显，放牧强度对试验区荒漠草地现存量峰值的出现时间及出现次数有明显影响；滩羊日采食量与放牧强度呈负相关，其回归方程为： y ＝２．０４－０．５４ x （ R 2 ＝ －０．８５， n ＝５５）。滩羊采食量呈现先增加后减少趋势，具有周期波动特性；滩羊采食率在整个放牧季呈单峰变化趋势；试验草地的适宜利用率为１０％～１５％。实践中，不能仅依靠草地现存量去确定草地载畜量，这往往会被草地现存量“过剩”的假象所迷惑，造成草地超载、退化。

 This study was conducted for revealing the Xilin Gol grassland forage nutrients status and rationally developing and utilizing of grassland ecological resources. According to forage nutrients measurement data from 2005 to 2011 provided by Xilinhot National Climate Observatory, the nutrients of Xilin Gol grassland forage were quantitatively and comprehensively evaluated by principal component analysis method. The results showed that values of forage nutrients in Sonid Left Banner were the highest, while those were lower in Ulgai Management District. The nutritive values of desertification steppe were the highest, followed by typical steppe, and those were the lowest in meadow steppe.

为揭示锡林郭勒草地天然牧草营养成分状况，合理开发利用草地生态资源，根据锡林浩特国家气候观象台2005－2011年天然牧草营养成分测定资料，应用主成分分析方法对锡林郭勒草地天然牧草营养成分进行了量化综合评价。结果表明，牧草饲料营养成分苏尼特左旗最高，乌拉盖管理区较低。荒漠化草原类型草地营养成分最高，其次为典型草原类型，草甸草原类型较低。

【目的】研究荒漠草原不同放牧强度下植物补偿性生长特征。【方法】通过不同放牧强度试验，研究荒漠草原植物种群，包括赖草（Leymus secalinus）、长芒草（Stipa bungeana）、糙隐子草（Cleistogenes squarrosa）和牛枝子（Lespedeza potanimii）等4种主要饲用植物的地上净初级生长量。【结果】荒漠草原植物在不同放牧强度下补偿性生长不同，在绵羊放牧强度0.60只/ha（2005年）或0.75只/ha（2006年）时表现为等补偿生长，小于此强度时则发生超补偿生长，大于此强度表现为欠补偿生长。4种主要饲用植物种群在不同放牧强度下补偿性生长特征也不尽相同。根据植物补偿性生长规律，该地区荒漠草原的适宜采食率为18.01%～33.82%。【结论】荒漠草原植物在放牧干扰下存在超补偿性生长情况，降低放牧强度有利于超补偿和等补偿生长的出现。

The experiment was conducted in Inner Mongolia steppe located at 43°-26'-44°8'N,116°04'-117°05'E,The vegetation was dominated by Artemisia frgada and short-grasses and the soil type issandy chestnut.The average precipitation was about 350mm which was main concerntration in summr andthe average temperature was-0.4℃.The grazing treatments included 5.stocking rates(1.33,2.67,4.00,5.33 and 6.67 sheep/hm 2 )with three 1hm 2 rotational paddocks at the beginning of 1990.Through 8 years studying,the results showed that the lighter stocking rate(1.33-2.67 sheep/hm 2 )can increase the proportion of grasses,such as Leymus chinensis ,Stipa krylovii and Agropyron cristatum,the plant diversities index and evenness and improve the rangeland condition; but the Artemisia frigida rangeland will be continue degradated to Potentilla acaulis rangeland which the proportion of grass herbageand plant diversity index were decreased.The Potentilla acaulis may be resistent to rangeland degradationang desertation furtherly.

研究不同放牧率的围栏轮牧。结果表明,在冷蒿小禾草退化草原,1.33-2.67羊/hm 2 的放牧率将使草原发生逆行范管,导致禾草的比例增大,植物多样性指数和均匀度指数均有所提高,从而达到利用式改良的目的。相反,若继续进行重牧或过牧,绵羊喜食的植物种类将进一步减少,植物多样性指数也有所降低。最终将趋同于星毛委陵菜退化草原群落,而星毛委陵菜则是防止草场沙化荒漠化的草种之一。

Alpine grassland is widely distributed in Northern Tibet. Stipa purpurea alpine grassland is one of the most important and representative meadow types in this area. In recent years, due to global warming and human activities such as overgrazing or excessive reclamation, the alpine grassland in Northern Tibet has undergone an accelerated and large-scale degradation. The grassland′s productivity and biological diversity have decreased significantly and locally, this has also become a great obstacle to sustainable social, economic and ecological development. To investigate community characteristics and α diversity of Stipa purpurea alpine grassland under different grazing intensity in Northern Tibet is critical not only to the understanding of local degradation mechanisms, but also to the establishment of rational grassland management procedures, as required for continued healthy and sustainable development of alpine grassland.In our study, based on a grazing experiment in Northern Tibet grassland ecosystem, the community characteristics of Stipa purpurea alpine grassland under different grazing intensity were investigated. The research was conducted at the grazing experimental site of Anduo County, Naqu, Tibet Autonomous Region, at an average elevation over 4,500 m above sea level. The experiment included four different stocking rates: no grazing (0 head/hm2, CK), light grazing (2.395 head/hm2, LG), moderate grazing (3.593 head/hm2, MG) and heavy grazing (5.988 head/hm2, HG). Based on the method of community investigation, community structure characteristics, such as species height, coverage and density were recorded. Aboveground biomass within areas of 0.5 m×0.5 m quadrat was also measured during the grass vigorous growth period. The species important value and summed dominance ratio were calculated by combining relative coverage, relative frequency and relative height. The species important value and summed dominance ratio were selected as comprehensive evaluation index of the importance of the species. The species diversity was measured using the Shannon-Wiener index and Pielou evenness index.The results showed that, with increasing grazing intensity, the above-ground biomass and the total coverage of plant communities followed a decreasing trend. Compared with the no grazing and light grazing treatments, the above-ground biomass and total coverage in the heavy grazing treatment were significantly lower. The important value of Stipa purpurea and other species was reduced gradually with increasing grazing intensity. Sedges such as Carex moorcroftii and other forbs, which the local livestock was rather avoiding, and also poisonous grasses were observed increased. The Shannon-Wiener index and Pielou evenness index changed according to the same pattern: MG﹥LG﹥HG﹥CK. The species diversity index of alpine grassland in this area reached the highest level under moderate grazing intensity. However, when the grazing intensity continued to increase beyond that level, the indices would decline rapidly.Comprehensive analysis indicated that the grassland had not only the highest diversity index under moderate grazing intensity, but could also resist a certain carrying capacity and prevent grassland degradation. Moderate grazing should be the most reasonable management strategy in Stipa purpurea alpine grassland. However, if grazing intensity continues to increase, the Stipa purpurea grassland type in this area would be transformed into a Carex moorcroftii, Herbarum variorum grassland community, which was clearly found to be of lesser economic and ecological value under the observed conditions.

基于放牧试验，研究了不同放牧强度下藏北地区紫花针茅(Stipa purpurea)高寒草原植物群落特征的变化规律。结果表明，随着放牧强度的增强，植物群落盖度、地上生物量均呈现显著降低的趋势；紫花针茅等禾草类植物的重要值逐渐降低，莎草类中青藏苔草(Carex moorcroftii)、牲畜不喜食的杂类草及有毒有害植物均有增加的趋势；如果持续过度放牧，植物群落表现出由紫花针茅等禾草为建群种的草地型向青藏苔草(Carex moorcroftii)、杂类草(Herbarum variarum)草地型过度的趋势；在中度放牧强度下，紫花针茅高寒草原α物种多样性达到最高水平，而继续增强放牧强度，则造成各项指标的迅速降低。

The effect of grazing disturbance on plant diversity,soil physical and chemical properties,and soil nutrients characteristics of Stipa Baicalensis Roshev.grassland was studied.The results show that the number of species,plant diversity and vegetation coverage were significantly decreased along with the increasing of grazing intensity.The effects of grazing disturbance on soil physical and chemical properties were primarily manifested in increased soil bulk density,decreased soil water content.Under heavy grazing,soil bulk density increased to 1.36 g/cm 3 ,soil water content decreased to 12.37%,vegetation coverage reduced,and the ground biomass was also significantly lower.Grazing disturbance led to the change of soil organic carbon pattern,soil organic carbon content in 0-10 cm decreased gradually with light grazing,but the organic carbon transferring to deep soil was accelerated,organic carbon levels in 10-20 cm and 20-30 cm were significantly higher than those in other plots,and soil organic carbon content of the profile increased 7.19% than non-grazing grassland.Total soil nitrogen content(0-10 cm,10-20 cm) increased under light grazing;under medium grazing,it was significantly higher than that in other plots.Soil total phosphorus content was not significantly different among plots,except that it was decreased significantly under heavy grazing.The increase of plant diversity,aboveground biomass,and underground biomass was a response to light grazing disturbance,while under heavy grazing,plant diversity and vegetation coverage reduced,soil physical and chemical properties changed,soil nutrient resource became scarce,and grassland appeared a trend of degradation.

以贝加尔针茅( Stipa baicalensis Roshev .)草甸草原为研究对象,研究不同强度放牧干扰对贝加尔针茅草原群落植物多样性、土壤理化性状及养分特征的影响。结果表明:随着放牧强度的增加,群落物种数、植物多样性和植被盖度均显著降低;放牧干扰对土壤理化性状的影响主要表现在,随着放牧强度的增加,土壤容重升高,土壤含水量减小,重度放牧草地土壤容重增加到1.35g/cm 3 ,含水量仅为12.37%;放牧导致土壤有机碳格局发生改变,轻度放牧下表层(0-10cm)土壤有机碳含量逐渐降低,但有机碳向深层土壤的转移量增加,深层土壤(10-20cm、20-30cm)有机碳含量均显著高于其它样地,且整个剖面土壤有机碳含量较对照样地提高了7.19%。土壤全氮含量(0-10cm、10-20cm)在轻度放时有所增加,中度放牧全氮含量显著高于其它样地,全磷含量除了在重度放牧时显著降低,在其它样地间均无显著差异。研究表明植物多样性、地上地下生物量的增加及土壤有机碳格局的改变是贝加尔针茅草原对轻度放牧干扰的一种响应,而重度放牧,草地植物多样性减少、植被盖度降低、土壤物理性状发生改变、养分资源趋于匮乏,草地出现退化的迹象。

Vegetation survey with fixedlocation has important significance to reveal the influence of the climate change and human activities on vegetation. In order to provide reference for the protection and rational utilization of meadow steppe, the field investigation data in 1983 and 2014 which had 31 years interval were analyzed using the methods of summed dominance ratio, relative height, relative coverage, relative abundance, relative frequency, relative weight, community diversity and similarity indices to real the main vegetation communities change in Xilingol meadow steppe under free grazing condition. The results showed that the meadow steppe adjacent to typical steppe shrunk to the east and Xilingol meadow steppe area decreased. The biggest change happened in Filifolium sibiricum steppe whose area decreased and transformed to Stipa baicalensis steppe and Leymus chinense steppe. The tested indices of Gramineae plants representing by S. baicalensis, L. chinense and Cleistogenes squarrosa including dominance, relative height, relative coverage, relative abundance, relative frequency and relative weight increased obviously whereas those of Compositae plants representing by F. sibiricum decreased obviously. There were no significant changes in Margarlef index and the number of families, genera and species. Simpson index, Pielou index and Similarity coefficient significantly decreased (P

定点植被调查对于揭示气候变化和人类活动等因素对植被的影响具有重要意义，本研究以间隔31年（1983年和2014年）的两期野外调查数据为基础，采用综合优势比、植被相对高度、相对盖度、相对多度、相对频度、相对重量、群落多样性和相似性指标，分析自由放牧状态下锡林郭勒草甸草原主要群落的植被变化，以期为草甸草原的保护与合理利用提供借鉴。结果表明,1）与典型草原邻近地段的草甸草原向东收缩，锡林郭勒草甸草原面积减小，变化最大的线叶菊（Filifolium sibiricum）草原转为贝加尔针茅（Stipa baicalensis）草原和羊草（Leymus chinense）草原，线叶菊草原面积减小。2）以贝加尔针茅、羊草和糙隐子草（Cleistogenes squarrosa）为代表的禾本科植物的优势度、相对高度、相对盖度、相对多度、相对频度和相对重量均明显增加，以线叶菊为代表的菊科植物各指标均明显减小，其他科植物变化较小。3）Margarlef丰富度指数和植物科、属、种数目均无显著变化（P>0.05），Simpson指数、Pielou均匀度指数和相似性系数均显著降低（P

“生态系统管理”是畜牧业可持续发展的重要理论基础。放牧家畜饲养周期长，出栏率低，是制约高寒草甸畜牧业生产的最大瓶劲。因此，采取一系列生态系统管理措施，如建立人工草地、修建牲畜暖棚并进行牛羊舍饲育肥、退化草地恢复与重建、优化畜群结构和优化放牧强度等，实现畜牧业的集约化经营，是高寒草甸畜牧业持续发展的必由之路。

Three grazing intensities were applied on Zhaosu Army-Horse Farm to compare variations of aboveground biomass and nutrient contents of plant community from 2011 to 2012. The results showed that aboveground biomass decreased under each treatment with extension of grazing time. For aboveground biomass, there were significant differences between different grazing treatments and the control area with the extension of grazing time in every year ( P ＜0.05). The crude protein contents of Thymus asiaticus, Medicago falcate, Carex liparocarpos, Stipa capillata and Festuca ovina decreased with the extension of grazing time, whereas there was no significant difference among different treatments. The dry matter contents of these 5 dominant species decreased and then slightly increased followed by further decrease during the whole grazing period although the fluctuation rate was 0.01%～2.00%. The neutral detergent fiber and the acid detergent fiber of these 5 dominant species increased with slightly decreased in the middle of grazing time. These observed variation of aboveground biomass and nutrient content showed that moderate grazing had less influence which was better for sustainable development of grassland. The effects of different grazing intensity on aboveground biomass and nutrient were far less than the effects of Inter-annual climate change.

于2011-2012年在新疆昭苏军马场进行了新疆褐牛放牧试验, 研究了不放牧和轻度、中度及重度放牧强度下的草地群落现存量及牧草营养物质含量。结果显示, 年际间各放牧强度下牧草地上现存量均呈现逐年降低趋势, 同一年内随放牧时间的延长, 各放牧处理与不放牧间差异显著( P )及杂类草的粗蛋白含量随放牧时间的延长均呈现降低趋势, 但不同放牧强度间降低的幅度差别不大;干物质含量随放牧时间呈先降低后升高再降低的趋势, 波动幅度介于0.01%～2.00%;中性洗涤纤维与酸性洗涤纤维含量均随放牧时间的延长呈先升高后降低再升高的趋势。中度放牧条件下牧草地上现存量下降幅度及牧草养分变化波动较小, 有利于草地的可持续利用;不同放牧强度对草地地上现存量及牧草营养物质的影响, 远不及年度间气候变化的影响大。

The responses of soil nutrients and plant community stability to different management modes,as well as the correlation between plant community stability and soil nutrients were studied in Stipa breviflora desert steppe in Ningxia. The results showed that the management modes significantly affected the variation of soil nutrients in 0～40 cm soil layer ( P P

以宁夏短花针茅( Stipa breviflora )荒漠草原为研究对象,研究不同管理方式(放牧、补播改良和封育)对土壤养分及植物群落稳定性的影响,并分析土壤养分与植物群落稳定性之间的相关性.结果表明:不同管理方式对荒漠草原0～40 cm土壤养分含量影响显著,封育和补播有利于土壤有机质、全氮、速效磷和速效钾含量的积累,中等强度的自由放牧较封育降低了土壤有机质、水解氮和速效钾含量;土壤养分的垂直分布规律并不一致,土壤有机质含量和全氮含量5~15 cm土层高于表层,而速效磷含量和速效钾含量表现为0～5 cm最高.不同管理方式下的荒漠草原植物群落均处于不稳定阶段,相比之下封育5年和7年草地植物群落稳定性较高;群落稳定性与土壤速效钾含量成显著正相关关系,与其他养分含量无显著相关性.

The grassland is one of important agriculture natural resources. However, the grassland degraded seriously in China because of overgrazing. At the beginning of 21st century, enclosure was praised highly as a primary mean for grassland ecological restoration in west China. Effects of enclosure on the vegetation, soil and grassland ecosystem restoration were reviewed in this paper. It was concluded that the moderate grazing is necessary to restore degraded grassland and long-term enclosure is not as good as expected. According to the degree of grassland degradation in different regions, the enclosure should be flexibly combined with reasonable rotation grazing intensity and time to restore degraded grassland and get animal products simultaneously. It was suggested that the grassland ecological system will be sustainable and in good balance when grassland and animals are in win-win.

草地是我国重要的农业自然资源之一,但目前草地退化的现象十分严重,超载过牧是主要原因之一。本文就针对草地退化提出的围封禁牧措施对草地植被、土壤及草地生态系统恢复过程中的作用进行综述,发现适度放牧对草地恢复是必需的,但采取长期围封禁牧恢复与重建草地的做法不可取,围栏封育并非恢复退化草地的万全之计。建议在我国要因地制宜,根据草地的退化程度,采取合理的划区轮牧强度和放牧时间,与退化草地生态恢复的围封措施结合,以达到既能恢复退化草地,又可收获畜产品的双赢目的,实现草地生态系统持续平衡发展的目标。