禁牧与放牧对新疆温性草原群落结构、生物量及牧草品质的影响

本试验研究了不同利用方式下温性草原植被特征及品质变化情况,旨在了解禁牧和放牧对草地群落产生的影响和群落变化过程,为合理利用与管理新疆温性草原提供理论依据。本研究以禁牧与放牧两种利用方式下的新疆温性草原为研究对象,2018年采用野外调查和室内分析相结合的方法,对整个生长季的草地群落生物量、数量特征、多样性及植被品质进行了动态观测。结果表明：放牧使群落基本数量特征（群落高度、盖度和密度）显著降低（P<0.05）,退化指示植物在群落中所占比重增加;与放牧草地相比,禁牧草地的群落优势物种生物量、总生物量均显著提高（P<0.05）,优势物种所占比重增加,群落丰富度下降,植物中粗蛋白含量降低,纤维含量显著增加（P<0.05）。本研究发现自由放牧会使草原群落向退化方向演替,长期禁牧会使得群落丰富度下降,在草原利用时要合理的将放牧与禁牧相结合,促进草地生态系统可持续发展。     

内蒙古自治区放牧地放饲方法

一、分区放牧法无系统的放牧对放牧地植被和收获量以及牲畜的产品率都有不良的影响。当草场无系统放饲时,最有饲用价值的植物很快地衰退,为营养价值低的粗糙的草类所代替。放牧地上不能吃的、有害的和有毒的植物数量有了增加。饲料的适口性由于践踏和牲畜粪便的污染显著降低。在这种利用放牧地的情况下很难获得畜牧业的高度产品率。在全年放牧饲养的地区,无系统的放牧将会带来特别重大的危害。不合理的放牧对牲畜肥育和抓膘都不利,结果使牲畜无法越     

牦牛干扰下草原毛虫对小嵩草高寒草甸植物群落特征的影响

采用野外受控放牧试验(放牧和不放牧)和人工控制草原毛虫(Gynaephora qinghaiensis)方法(草原毛虫移除和未移除),研究了牦牛干扰下草原毛虫对高寒草甸小嵩草(Kobresia pygmaea)草地植被群落(植被盖度、群落高度、地上生物量及植物多样性等)的影响。结果表明,在试验期内,草原毛虫种群数量随着时间的推移呈现出先增加后降低的趋势。在牦牛(Bos mutus)放牧区内草原毛虫种群数量及增长趋势均高于无牧区。草原毛虫单独存在时群落的盖度、高度及地上总生物量与对照(牦牛与草原毛虫都不存在,CK)差异不显著(P0.05),而牦牛与草原毛虫共存时群落盖度、高度及地上总生物量都显著低于CK(P0.05)。牦牛干扰了草原毛虫对群落中主要植物种的作用,植物重要值发生了显著变化。草原毛虫单独存在时植物多样性指数与CK间无显著差异,单独放牧牦牛和牦牛与草原毛虫共存时的植物多样性指数均显著低于CK(P0.05)。本研究表明,牦牛显著加剧了草原毛虫对小嵩草高寒草甸植被的影响。     

放牧对内蒙古荒漠草原草地植被及土壤养分的影响

以内蒙古荒漠草原为研究对象,分析一个生长季内不同放牧强度下荒漠草原植被和土壤养分变化状况。试验设置禁牧CK)、轻度放牧(LG)、中度放牧(MG)和重度放牧(HG)4个放牧梯度。结果表明,随着放牧强度的增加,草地植被地上生物量减少,且生长旺季(8月),轻度放牧、中度放牧和重度放牧比禁牧分别降低了7.47%、41.96%和51.75%;草地植被群落生物多样性变化不显著(P0.05);植被物种丰富度随着放牧强度增加而下降;放牧强度对土壤有机质和土壤全氮无显著影响;植被群落生物多样性与表层土壤有机质呈负相关关系。     

家庭牧场不同放牧方式对草甸草原植物群落的影响

草原家庭承包制的推广实施改变了传统放牧制度,变化的放牧方式对草原植被群落造成不同影响。本研究通过对比分析内蒙古陈巴尔虎旗草甸草原3种放牧方式草场植物群落组成及α多样性指数,探究不同放牧方式对植物群落结构及多样性的影响,为改进草原家庭承包制提供参考依据。研究结果表明:四季轮牧草场的植物种数最多,四季轮牧与两季轮牧草场的原生建群种重要值较大,定居放牧草场中出现了大针茅(Stipagrandis)、羊草(Leymus chinensis)及星毛委陵菜(Potentilla acaulis),且星毛委陵菜的重要值最大。四季轮牧草场植物的Shannon-wiener指数、Margalef指数、Simpson指数、Pielou指数均高于两季轮牧与定居放牧草场,且与定居放牧草场相比,Shannon-wiener指数与Margalef指数差异显著(P0.05),两季轮牧草场与定居放牧草场的4种α多样性指数均无显著差异。Shannon-wiener指数与Margalef指数、Simpson指数、Pielou指数的相关系数分别为0.9421,0.5825,0.8550(P0.01)。从群落结构及生物多样性角度考虑,四季轮牧更有利于草场群落复杂结构及生物多样性的保持。     

放牧强度对羊草草原的影响

研究放牧强度对羊草草原植物群落组成、数量特征、生物量及土壤特性等的影响.结果表明,随着放牧强度的增加,羊草草原的植被盖度和生物量随之降低,优势羊草群落将逐渐被盐生植物所替代,群落结构趋于简化,物种向旱生化和盐生化演替.同时土壤容重、含水量、有机质和氮、磷、钾、钙、镁等营养元素含量亦随着放牧强度的增加而逐渐降低.春季过度放牧对土壤表层的水分、有机质和钙、镁等元素造成的损失最为严重.因此,制定科学的草原管理措施,特别是春季限制放牧等措施对于维持草原的可持续发展具有重要意义.     

放牧强度对羊草草原的影响

研究放牧强度对羊草草原植物群落组成、数量特征、生物量及土壤特性等的影响.结果表明,随着放牧强度的增加,羊草草原的植被盖度和生物量随之降低,优势羊草群落将逐渐被盐生植物所替代,群落结构趋于简化,物种向旱生化和盐生化演替.同时土壤容重、含水量、有机质和氮、磷、钾、钙、镁等营养元素含量亦随着放牧强度的增加而逐渐降低.春季过度放牧对土壤表层的水分、有机质和钙、镁等元素造成的损失最为严重.因此,制定科学的草原管理措施,特别是春季限制放牧等措施对于维持草原的可持续发展具有重要意义.     

不同放牧密度对草原植被特征的影响分析

呼伦贝尔天然草原在不同放牧半径条件下的草原植被演替特征，包括植被组成、群落主要植物的优势度、植被演替度、植被高度、盖度以及生产力与放牧强度的变化关系等。结果分析表明：呼伦贝尔草原放牧密度的差异将导致植被组成中的减少种、增加种与侵入种比例呈有规律改变，特别是随放牧密度的增大，侵入种比例急剧开始升高；同时草原植被中优势种比例下降，而且植被演替度减小，植被生产力下降。应用植被生态学的定量分析方法，对不同     

贯彻落实《中华人民共和国草原法》知识问答(Ⅱ)

6　农区、半农半牧区和有条件的牧区为什么要逐步改变依赖天然草地放牧的生产方式 ?长期以来 ,广大农牧民习惯于依赖天然草地放牧发展草原畜牧业。但长期掠夺式的超载过牧和粗放经营 ,不仅造成草原退化、沙化、碱化日趋严重 ,而且引发的草畜矛盾尖锐和生态环境日益恶化的趋势。在农区、半农半牧区和有条件的牧区实施禁牧、休牧、划区轮牧和牲畜舍饲圈养的意义重大。一是从根本上解决超载放牧问题 ,草原植被能够得到恢复。牲畜数量的逐步增加对草原长期长年无节制的随意放牧 ,是草原遭受破坏的主要原因。实施禁牧、休牧、划区轮牧和牲畜舍饲…     

探讨高原放牧强度对高寒草原植被群落产生的影响

草原植被覆盖程度和产物量与放牧强度有较为直接的关系,尤其对高原地区来说,牦牛作为重要的经济物种,其饲养以放牧为主,如果不注意控制放牧的强度,会造成草原植被覆盖程度降低、生物量减少,盐生植物将取代优势草群落,群落结构更趋于简单化,物种会向旱生化和盐生化演变,而土壤中的成分也会随之改变,因此必须要有效的控制高原地区放牧的强度.     

Effects of Livestock Grazing Management on Grassland Birds in a Northern Mixed-Grass Prairie Ecosystem

Grassland birds have undergone substantial population declines throughout much of their historic ranges in North America. Most of the remaining grassland bird habitat is restricted to rangelands managed for livestock production, so grazing management has strong implications for grassland bird conservation efforts. We conducted 1 830 point-count surveys at 305 sites during 2016–2017 to evaluate the relative effects of three livestock grazing systems on the abundance and community composition of grassland birds in a northern mixed-grass prairie ecosystem of eastern Montana, United States. Our objectives were to 1) evaluate effects of grazing management on abundance and community composition of grassland obligate birds, focusing specifically on grazing systems, stocking rates, and interactions with rangeland productivity; 2) evaluate the importance of local vegetation characteristics for grassland birds within grazing systems; and 3) assess the effectiveness of rest-rotation grazing to create patch-heterogeneity in rangeland vegetation through the alteration of structural components and the response of grassland birds to these treatments. Overall, we found inconsistent responses in abundances of grassland birds relative to livestock grazing systems and no discernable differences among grazing systems relative to community composition. However, local abundances were often driven by interactions between grazing system and rangeland production potential, suggesting the effects of livestock grazing management were generally mediated by rangeland productivity. In addition, associations between avian abundance and grazing management parameters (e.g., stocking rate) were species specific. Ubiquitous guidelines for livestock grazing systems may be inappropriate for grassland bird conservation efforts in the northern mixed-grass prairie, and high stocking rates may negatively impact populations of dense-grass obligate grassland birds in this region.     

Effects of Twice-Over Rotational Grazing on Songbird Nesting Success in Years With and Without Flooding

Rotational grazing is sometimes promoted for grassland bird conservation, but the benefits to wildlife have not been comprehensively documented. We examined effects of twice-over rotational grazing on nesting success of grassland songbirds in southwestern Manitoba, Canada in comparison to season-long grazing. We monitored nesting attempts and collected structural vegetation data in 2011 (during a 1/300 flood event), and 2012 (average water levels), for five species of obligate grassland bird species (n = 110) and one shrub-nesting species (n = 41). Nesting analyses were conducted using logistic exposure models. Nesting success was 2.4 to 4 times lower in twice-over grazed pastures compared with season-long grazed pastures, perhaps because of the increased cattle density during the short grazing periods of the twice-over system. Nests protected by shrubs from grazing activities of cattle did not show this pattern. The grazing system did not have an effect on vegetation structure. This suggests that twice-over rotational grazing does not benefit grassland songbirds in northern mixed-grass prairies, and that caution must be taken before implementing this grazing system in areas intended to promote biodiversity conservation.     

Twice-Over Rotational Grazing and Its Impacts on Grassland Songbird Abundance and Habitat Structure

The majority of native prairie has been lost throughout North America. Much of the remaining prairie is used for livestock grazing, so conservation of prairie species depends on sustainable grazing practices. Our objective was to evaluate the benefits of twice-over rotational grazing, in comparison with continuous season-long grazing and ungrazed “idle” fields, in conserving prairie songbirds. Northern mixed-grass prairie in southwest Manitoba, Canada is near the northern range limits for many endangered grassland birds, and thus is an important area for evaluating the contribution of twice-over grazing in the conservation of songbirds, including species at risk. In 2008 and 2009, we compared the relative abundances and diversity of grassland birds on 22 twice-over rotation, 15 season-long, and 8 ungrazed sites, using multiple 100-m fixed-radius point-count plots per site. Analyses were conducted using generalized linear mixed models. Although one obligate grassland bird, Savannah sparrows (Passerculus sandwichensis), had significantly higher relative abundances on twice-over than season-long sites in 2009, season-long pastures had higher species richness and diversity of obligate grassland birds in both years. Season-long grazing may actually benefit grassland bird communities by creating spatially heterogeneous but temporally stable areas of high and low livestock use within the pasture, thus increasing diversity of microhabitats. We found little evidence that twice-over grazing contributed to the conservation of grassland songbirds in subhumid northern mixed-grass prairies.     

盐池草地禁牧期间农牧民违规放牧现象分析

随着禁牧政策的全面实施,放牧草地得以休养生息.但禁牧区农牧民从其短期经济效益出发,违规进行放牧以增加经济收入,以致政府全面禁牧的宏观政策不能很好地执行,部分草场生态再次恶化.为此根据草场面积、草场管理方式、地理位置等综合因素在禁牧区选择了234户农牧户用抽样调查和实地调查的方法对农牧户的违规放牧行为进行调查,并从养殖成本、地理位置、草场使用权界定、禁牧政策等方面探讨分析农牧民违规放牧行为发生的原因,寻求改变禁牧区农牧民的生产行为方式,解决禁牧与放牧矛盾,以达到保护和合理利用草场、恢复生态、增加农牧民经济收入的目的.     

基于放牧系统单元的草地可持续管理:概念与模式

放牧系统单元是放牧过程中形成的草地、家畜、人居三位一体的稳定格局,具有移动性、适应性、灵活性、多样性、地带性(地理地带性和时间地带性)和脆弱性,可以提供支持(如土壤保持)、供给(如草畜产品)、调节(如气候调节)、文化(如文化传承)等多种服务功能。放牧系统单元的组分?草地、畜群、人居之间的相互割裂是放牧管理不当的严重问题,容易造成草地退化和牧民贫困等生态和经济问题。放牧系统单元的重建对我国草地畜牧业转型适应具有重要意义,根据自然环境和社会经济条件,放牧系统单元的重建可以采取3种模式:1)联户/合作社为单位的现代游牧模式;2)家庭/小型牧场为单位的定居放牧模式;3)合作社/大型牧场为单位的划区轮牧模式。     

放牧强度对内蒙古典型草原群落结构和家畜生产性能的影响

认识放牧对草地植物群落结构和家畜生产性能的影响是修复放牧退化草地和制定可持续放牧体系的理论基础。本研究在内蒙古锡林郭勒典型草原开展了基于草地放牧留茬高度的适应性放牧实验,连续4年监测了无牧(NG)、轻牧(LG)、中牧(MG)和重牧(HG)条件下草地植物群落的变化和家畜生产性能,分析其对放牧强度的响应。结果表明：与NG相比,HG显著降低了优势种的相对生物量,提高了伴生种的相对生物量(P<0.05);LG和MG处理下主要提高了优势种的生产力,而在HG处理主要提高了伴生种的生产力;在所研究的典型草原采用适应性放牧方式下,中度放牧可获得最佳的草地植物生产和家畜生产性能。研究为制定合理的草原放牧制度、促进草地群落结构优化和草畜平衡发展提供了理论依据。     

Human–wildlife conflict and attitude of local people towards conservation of wildlife in Chebera Churchura National Park,Ethiopia

Human–wildlife conflict is a serious challenge undermining the integrity of protected areas in developing countries. Developing effective human–wildlife conflict mitigation strategies requires an understanding of the conflict patterns, species involved and attitudes of local people living along protected area boundaries. We hypothesised that (1) there was a high level of human–wildlife conflict and (2) the local people would have less favourable attitudes towards problematic wild animals. We assessed patterns of human–wildlife conflict and attitudes of local people along the boundary of Chebera Churchura National Park, Ethiopia from 2012 to 2014. A total of 354 households were selected randomly for interview. A questionnaire survey, focus group discussions and direct field observations were carried out in the selected villages. The major types of human?wildlife conflict in the area include crop raiding, livestock predation, increased risk of livestock diseases and direct threats to human life. A majority of the respondents (68.1%) faced crop damage and domestic animal loss, 12.3% reported threat to humans and 0.3% reported that the wildlife might cause diseases. Close proximity of the villages to the park and seasons influenced livestock predation intensity with highest predation in the wet season (56.0%). To mitigate these problems, the local people utilised various traditional methods, including guarding. Most respondents had positive attitudes towards the conservation of wildlife. However, as the frequency of conflicts increased in the last five years, the attitudes of local people might change. Active measures are to be implemented to mitigate the problem and safeguard the future of the wildlife around the park. The park has enormous potential to benefit more local people by implementing a participatory management approach to conservation.     

Simulation of Pastoral Management in Mongolia: An Integrated System Dynamics Model

High grazing density has given rise to concerns about grassland degradation in periurban areas in Mongolia. Moreover, whether livestock can increase without harming the vegetation in these areas in Mongolia and what types of policy measures should be implemented is not documented. As such, this study develops an integrated simulation model of grassland biomass, animal growth, and livestock management for a forest-steppe area in northern Mongolia and conducts a simulation on long-term changes. The simulations show that, under current conditions, the number of animals will continue to increase, while the grassland biomass will decrease. Cooperative grassland management would lead to an increase in grassland biomass and higher incomes for herders. Furthermore, herders’ population changes would have a significant impact on animal density adjustments, while the effects of conventional economic measures, such as a tax on animals, would be limited if all other conditions remain constant. Consequently, the synergistic effects of herder population changes and cooperative management can contribute toward maintaining the herders’ income while preserving the grassland ecosystem.     

Long-Term Livestock Exclusion in an Arid Grassland Alters Vegetation and Soil

Changes in soil and vegetation due to livestock grazing are occurring in arid lands throughout the world. The most extreme cases result in desertification, which is seen as largely irreversible, because of altered soil properties. To understand better how long-term livestock removal affects soil properties and vegetation, we compared water-infiltration rates, soil bulk density, and perennial grass cover inside and outside a long-term livestock exclosure in an arid grassland site in southeastern Arizona, United States. The site had not been desertified at the time of this study. Exclusion of livestock for 40 yr was associated with lower bulk density and higher water infiltration in both the dry and wet seasons. Perennial grass cover was higher and two native grasses, Eragrostis intermedia and Bouteloua hirsuta were significantly more common (P < 0.05) in the ungrazed area. These findings parallel our results from a desertified site and suggest that changes in soil physical properties associated with long-term livestock removal are not an artifact of desertification and can take place in a system that has remained in a grassland state. Our data suggest that, although significant changes in species composition have occurred, this grassland is relatively resilient to substantial changes in soil physical properties.     

Behavioral and Ecological Implications of Bunched,Rotational Cattle Grazing in East African Savanna Ecosystem

Rangelands and the wildlife and livestock they support are critical to human livelihoods, but rangeland ecosystems increasingly suffer from overgrazing and degradation. Planned grazing, a strategy that commonly involves time-controlled rotations of high-density (bunched) groups of cattle across a pasture, is marketed as a method to enhance rangeland health and lessen livestock impacts. However, the behavioral mechanisms underlying any potential rangeland improvements resulting from rotational, high-density planned grazing have rarely been examined. To investigate these mechanisms, we compared planned grazing with conventional continuous grazing management in a savanna ecosystem in Kenya. We surveyed cattle grazing behavior, measured changes in vegetation characteristics through surveys conducted before and after cattle grazing, and measured native ungulate abundance following grazing using camera traps. Stocking rates were held constant across treatments, resulting in a commensurate decline in total foliar hits per pin (a proxy for vegetative biomass) across treatments. Planned grazing management altered cattle behavior and reduced grazing selectivity by restricting movements, causing cattle to walk more slowly while grazing and to take more bites per step. Vegetation survey results supported this finding: cattle in the planned grazing treatment ate significantly more Pennisetum grasses (typically avoided because of their unpalatability), creating the opportunity for regrowth of more palatable species after seasonal rains. We also documented significantly higher zebra presence in planned grazing plots after cattle grazing, likely due to increased relative abundance of more palatable grass species. This investigation of grazing behavior, and specifically decreased grazing selectivity as a mechanism underpinning the benefits of planned grazing, shows that when conducted at appropriate stocking densities, planned grazing has the potential to help mitigate rangeland degradation and improve rangeland sustainability for both livestock and wildlife in pastoral African savanna ecosystems.