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1.
Ecosystem services are benefits humans obtain as a result of ecosystem processes and conditions. In the western United States, public rangelands are managed for a spectrum of ecosystem services on behalf of multiple stakeholders. Decisions of ranchers who hold public land grazing allotments must balance operational needs for forage with societal expectations for other ecosystem services. To better understand their choices regarding ecosystem services, we interviewed ranchers to learn about the bases for their management decisions and identify services they believe rangelands provide. A total of 19 services were identified, many of which reflected ranchers’ recognition that they manage within the context of a broader social-ecological system (e.g., maintaining open space). We then conducted a mail survey of Bureau of Land Management grazing permittees in six states to understand the importance they personally place on different services, as well as the extent to which they manage with those services in mind. Fourteen of the 19 ecosystem services identified in interviews were reported by at least 50% of the survey sample (N = 435) as influencing their management decisions. Most respondents reported trying to manage deeded and leased land to the same standard. Aside from forage for livestock (ranked #1), ranchers were less likely to report managing for provisioning services than for cultural, supporting, and regulating services. Importance ratings for ecosystem services followed a similar pattern, although there were a few differences in rank order. Ranchers tended to report managing for more ecosystem services if they had larger operations, earned at least 50% of their income from ranching, spent more time out on the ranch, and relied on multiple sources for information about range management. Results indicate public land ranchers believe they are managing for multifunctionality, balancing their own operational needs with those of society.  相似文献   

2.
Research on the impacts of wildfire and invasive plants in rangelands has focused on biophysical rather than human dimensions of these environmental processes. We offer a synthetic perspective on economic and social aspects of wildfire and invasive plants in American deserts, focusing on the Great Basin because greater research attention has been given to the effects of cheatgrass expansion than to other desert wildfire/invasion cycles. We focus first on impacts at the level of the individual decision-maker, then on impacts experienced at the human community or larger socio-political scales. Economic impacts of wildfire differ from those of invasive grasses because although fire typically reduces forage availability and thus ranch profit opportunities, invasive grasses can also be used as a forage source and ranchers have adapted their grazing systems to take advantage of that circumstance. To reduce the threat of increased ranch bankruptcies, strategies are needed that can increase access to alternative early-season forage sources and/or promote diversification of ranch income streams by capturing value from ranch ecosystem services other than forage. The growth of low-density, exurban subdivisions in Western deserts influences not only the pattern and frequency of wildfire and plant invasions but also affects prevailing public opinion toward potential management options, and thereby the capacity of land management agencies to use those options. Outreach efforts can influence public opinion, but must be rooted in new knowledge about multiple impacts of invasion and increased wildfire in American deserts.  相似文献   

3.
This article examines the question of how well the rangeland management profession has served conservation of patterns and processes that support multiple ecosystem services. We examine the paradigms under which rangeland management operates and argue that our profession developed under the utilitarian paradigm with the primary goals of sustainable forage for livestock production. While optimization of multiple rangeland products and services has always been a consideration, a comprehensive set of principles have not be been developed to advance this concept. We argue that fire and grazing, often viewed as mere tools used for production goals, should rather be viewed as essential ecosystem processes. Rangeland management continues to operate under the utilitarian paradigm appropriate to societal values of the 20th century and by and large has failed to provide management guidance to reverse degradation of several highly valued ecosystem services. We support this argument with evidence that biodiversity has declined on rangelands in the past half century and that much of this decline is due to management goals that favor a narrow suite of species. The full suite of ecosystem services valued by society will only benefit by management for heterogeneity, which implies that there is no one goal for management and that landscape-level planning is crucial. Explicitly incorporating heterogeneity into state-and-transition models is an important advancement not yet achieved by our profession. We present new principles for rangeland management formed on the basis of conservation of pattern and process. While recognizing that many rangelands have significant deviations from historic plant communities and disturbance regimes, we suggest that management for conservation of pattern and process should focus on fire and grazing to the extent possible to promote a shifting mosaic across large landscapes that include patches that are highly variable in the amount of disturbance rather than the current goal of uniform moderate disturbance.  相似文献   

4.
Rapidly increasing demand for food, fiber, and fuel together with new technologies and the mobility of global capital are driving revolutionary changes in land use throughout the world. Efforts to increase land productivity include conversion of millions of hectares of rangelands to crop production, including many marginal lands with low resistance and resilience to degradation. Sustaining the productivity of these lands requires careful land use planning and innovative management systems. Historically, this responsibility has been left to agronomists and others with expertise in crop production. In this article, we argue that the revolutionary land use changes necessary to support national and global food security potentially make rangeland science more relevant now than ever. Maintaining and increasing relevance will require a revolutionary change in range science from a discipline that focuses on a particular land use or land cover to one that addresses the challenge of managing all lands that, at one time, were considered to be marginal for crop production. We propose four strategies to increase the relevance of rangeland science to global land management: 1) expand our awareness and understanding of local to global economic, social, and technological trends in order to anticipate and identify drivers and patterns of conversion; 2) emphasize empirical studies and modeling that anticipate the biophysical (ecosystem services) and societal consequences of large-scale changes in land cover and use; 3) significantly increase communication and collaboration with the disciplines and sectors of society currently responsible for managing the new land uses; and 4) develop and adopt a dynamic and flexible resilience-based land classification system and data-supported conceptual models (e.g., state-and-transition models) that represent all lands, regardless of use and the consequences of land conversion to various uses instead of changes in state or condition that are focused on a single land use.  相似文献   

5.
The ecological impacts of rangeland invasive plants have been widely documented, but the social aspects of how managers perceive their impacts and options for control have been relatively understudied, and successful, long-term invasive plant management programs are limited. In particular, though a growing body of research has identified livestock grazing as the most practical and economical tool for controlling invasive rangeland plants, to date there has not been a systematic assessment of the challenges and opportunities producers and other land managers see as most important when considering using livestock to manage invasive plants. In-depth, semistructured interviews with California annual grass and hardwood rangeland ranchers, public agency personnel, and nongovernmental organization land managers were used to address this need. Although interviewees broadly agreed that grazing could be an effective management tool, differences emerged among the three groups in how they prioritized invasive plant control, the amount of resources devoted to control, and the grazing strategies employed. Interviewees identified key challenges that hinder broad-scale adoption of control efforts, including the potential incompatibility of invasive plant management and livestock production; a lack of secure, long-term access to land for many ranchers; incomplete or insufficient information, such as the location or extent of infestations or the economic impacts to operations of invasive plants; and the temporal and spatial variability of the ecosystem. By identifying key socioecological drivers that influence the degree to which livestock are used to manage invasive plants, this study was able to identify potential pathways to move our growing understanding of the science of targeted grazing into practice. Research, extension, and grazing programs that address these barriers should help increase the extent to which we can effectively use livestock to slow and perhaps reverse the spread of some of our most serious rangeland weeds.  相似文献   

6.
Holistic Planned Grazing? (HPG) is purported to have positive long-term effects on rangelands, enhancing ecosystem services. Given comparable environmental templates, but different management regimes, vegetation monitoring and landscape function analysis showed the Africa Center for Holistic Management (ACHM) at Dimbangombe had a significantly higher rangeland condition (composition, cover, standing crop and soil health) than adjacent Sizinda (SCR) and Monde (MCR) communal rangelands. Overall grazer density on ACHM is 42% higher than that of SCR (no data for MCR). Finer-scale satellite collar data for ACHM yielded a calculated stocking rate of 0,55 LSU ha-1 y-1 or 24 590 kg km-2, which constitutes high-density grazing. An energy flow estimate shows that the grazing resource would, on average, not be limiting for livestock on ACHM but limiting on SCR. HPG may include an element where kraals are inserted into degraded rangelands for a short period. Overall, ACHM shows stable perennial composition with smaller tufts significantly closer together. A similar result was visible in SCR where maize yields were visibly higher on kraaled areas than on adjacent untreated fields. HPG yields positive long-term effects on ecosystem services (soils and vegetation) and points to the HPG approach enhancing the sustainability of livestock and wildlife in this environment.  相似文献   

7.
Managing the environmental risk associated with livestock production is a significant challenge. Nitrogen and phosphorus are commonly implicated as the sources of ground and surface water quality problems associated with livestock production. The degree of imbalance between these nutrient inputs and the managed nutrient outputs for a livestock operation defines the magnitude of potential environmental risk and provides insight as to the underlying causes of these challenges. A nitrogen and phosphorus balance was constructed for 33 Nebraska confinement livestock operations. Twenty-five and 17 of these operations experienced significant nitrogen and phosphorus imbalances, respectively (50% more nutrient inputs than outputs). Nutrient inputs on many livestock operations were observed to be two to four times greater than nutrient outputs as managed crop and livestock products. Size of the livestock operation and the degree of integration of livestock with a cropping operation provided only limited explanation of the variation in nutrient balance observed among the individual operations. Management options that contribute to a more favorable nutrient balance were also identified. Management decisions related to feeding program and exporting of manure nutrients to off-farm users were observed to have a substantial impact on the nutrient imbalance. For modern livestock production systems to successfully respond to nutrient-related environmental problems, management strategies must be implemented that address the commonly experienced imbalances of nitrogen and phosphorus.  相似文献   

8.
Assessments of society’s perceptions of rangeland systems offer insights into the motivations, cultural beliefs, and values that can support landscape conservation and the everyday decisions of landowners. Silvo-pastoral landscapes, the grazed oak woodlands known as montado in Portugal and dehesa in Spain, are the main rangelands of southwestern Iberia. At the interface of complex interactions between natural processes and human activities, they have potential to deliver multiple services at the ecosystem level. However, the actual rendering of their potential to the well-being of contemporary society has not been comprehensively documented. This paper aims to enrich research perspectives and identify benefits and challenging aspects of silvo-pastoral landscapes through the lens of society well-being. An integrated socioecological perspective is used to examine one case study in Portugal and one in Spain. To better understand their context, montado and dehesa are assessed relative to other landscape types in the studied areas. A qualitative approach assesses tangible but also intangible aspects. The interviewed stakeholders include members of rural communities, public authorities, land managers, and researchers. Results reveal similar benefits and challenges in montado and dehesa. Interviewees considered them to have numerous sociocultural and environmental benefits. These were mainly regulatory services but also intangible benefits such as cultural identity, aesthetic qualities, and local knowledge. Nevertheless, a rendering of their full potential to society well-being has numerous challenges. These systems were believed to struggle economically, due to the low prices for the goods produced and a high dependence on subsidies. Their environmental vulnerability was also highlighted. Critical challenges for future research and policy interventions are identified for both case studies. Moreover, we encourage the wider application of approaches to rangelands focusing on well-being, as they provide a complement to ecological and economic perspectives that can improve understanding of social-ecological systems.  相似文献   

9.
美国草原管理法律法规发展概况   总被引：5，自引：2，他引：3  
草地资源的立法管理是各国管理草地资源防止草地退化的主要人为调控手段。美国草原立法开始早,立法体系完善,对美国公共草地合理管理做出了巨大贡献。美国草地立法经历了3个阶段:首先是草原立法和管理主要在各州层面上,对公共草地管理作用不大,使西部公共草地处于无序利用状态,草地退化严重;第二是《泰勒放牧法》颁布后,开始了公共草地管理,建立了有照放牧和放牧收费制度;第三是美国草地的多用途管理,出台了与草地资源管理相关的一系列法律,主要是《环境政策法》和《联邦土地政策管理法》,草地资源相关价值受到高度重视。在国家立法规定下,对草地资源的价值进行评估。研究美国草地立法过程和立法思想,对于合理管理中国草地资源具有重要指导意义。  相似文献   

10.
草地放牧系统优化模型的研究进展   总被引：1，自引：2，他引：1  
生态学研究的定量化发展,以及环境资源管理的迫切需求,伴随着计算机的广泛使用,生态模型作为生态系统研究的重要工具,从19世纪20年代至今发展十分迅速,在生态系统研究的各个领域都有很好的应用。草地放牧系统作为生态系统重要组成部分,对其研究自然也离不开模型的应用。本研究对草地放牧系统优化模型的研究进行了评述。具体阐述了以下几个方面:1)草地放牧系统的概念以及与草地生态系统的区别与联系;2)基于环境资源的不断恶化以及生产实践的迫切要求讨论了草地放牧系统优化的意义;3)从植物生产亚系统、动物生产亚系统、管理亚系统3个方面阐述草地放牧系统优化模型的研究进展,以及其中存在的问题;4)主要集中在模型目标、技术手段和实证问题几个方面对于草地放牧系统的发展方向进行了展望。  相似文献   

11.
The debate regarding the benefits of rotational grazing has eluded resolution within the US rangeland profession for more than 60 yr. This forum examines the origin of the debate and the major reasons for its persistence in an attempt to identify common ground for resolution, and to search for meaningful lessons from this central chapter in the history of the US rangeland profession. Rotational grazing was a component of the institutional and scientific response to severe rangeland degradation at the turn of the 20th century, and it has since become the professional norm for grazing management. Managers have found that rotational grazing systems can work for diverse management purposes, but scientific experiments have demonstrated that they do not necessarily work for specific ecological purposes. These interpretations appear contradictory, but we contend that they can be reconciled by evaluation within the context of complex adaptive systems in which human variables such as goal setting, experiential knowledge, and decision making are given equal importance to biophysical variables. The scientific evidence refuting the ecological benefits of rotational grazing is robust, but also narrowly focused, because it derives from experiments that intentionally excluded these human variables. Consequently, the profession has attempted to answer a broad, complex question—whether or not managers should adopt rotational grazing—with necessarily narrow experimental research focused exclusively on ecological processes. The rotational grazing debate persists because the rangeland profession has not yet developed a management and research framework capable of incorporating both the social and biophysical components of complex adaptive systems. We recommend moving beyond the debate over whether or not rotational grazing works by focusing on adaptive management and the integration of experiential and experimental, as well as social and biophysical, knowledge to provide a more comprehensive framework for the management of rangeland systems.  相似文献   

12.
It is hypothesized that Utah beef producers in certain locations could intensify private land use via improved forages and irrigation. Although intensification could increase ranch productivity and help compensate for any future restrictions in public grazing, is the approach profitable and sustainable in a dynamic environment? We investigated the efficacy of intensification using linear programming for three size-classes of model ranches. Model solutions maximize returns net of forage costs; outputs include brood-herd dynamics, optimal forage mixes, and net returns. The model is driven by 11-year risk scenarios combining high or low precipitation with high or low beef prices. We then consider current or no access to public grazing—a policy uncertainty. In general, results support the idea that intensification could be profitable, sustainable, and strategically useful under several sets of conditions. Modeled brood-herds expand and contract in response to precipitation. Optimal forage use is dominated by reliance on treated, improved, and irrigated forages. Critical irrigated forages include alfalfa hay and improved pasture. Profitability generally increases with operation size, but when public grazing is eliminated, herd sizes and profitability drop. Small and medium-sized operations respond to loss of public grazing by using more irrigated pasture and alfalfa hay, while larger operations use a wider variety of irrigated and nonirrigated forages. Sensitivity analysis indicates that optimal forage mixes for all operations remain stable even when input costs for fossil fuels double. Further increases in fuel costs, however, begin to reduce the contributions from irrigated pasture and alfalfa hay. Low precipitation (drought) has very large and negative effects on profitability in general. When drought combines with restricted access to public grazing, profitability of small and medium-sized operations drops further while profitability of large operations increases. Empirical research is needed to test model results and examine what the limiting assumptions reveal about real-world production constraints.  相似文献   

13.
姜晓群  林哲艳  时钰  赵晋灵  李昂 《草业学报》2020,29(11):151-164
当初步遏制草地退化后,我国当前迫切需要对草地管理政策进行优化和调整,进而更好地通过草畜平衡和生态补贴实现生态保育和牧民利益的协调和可持续发展目标。长达90年的美国公共放牧地政策可以为我国调整和优化草地管理政策提供借鉴。美国经验表明,实现草地生态保育需要在社会共识、法律体系和行政管理等方面,牢固地树立和实现草地的多重功能和生态系统服务理念。进一步地,公有的草地产权制度是保障草地多重生态系统服务的法律前提,非牧产业发展是实现草地多重功能的经济基础,精细的行政管理是实现草地生产生态平衡的技术保障,多种利益主体参与是实现草地管理制度改革的活力来源。美国草地管理制度发展的曲折反复,也说明了生态管理政策的失效和调整,禁牧和监管强度的张弛反复,不同利益集团的矛盾诉求和博弈消长,都是草地治理中的正常情况。我国草地治理也可能经历复杂曲折的过程。在下一阶段,草地产权的优化、行政管理的精细化、牧民利益和生态保育目标的协调,是实现我国草地可持续治理的核心要务。  相似文献   

14.
Rangeland management strategies impact biodiversity, the quality and quantity of ecosystem services, and overall rangeland resiliency. Previous management strategies, coupled with climate change, have led to widespread invasion by Kentucky bluegrass (Poa pratensis; bluegrass) in the Northern Great Plains, United States. Bluegrass invasions are expected to have detrimental impacts on biodiversity conservation and ecosystem services provided by rangelands. Yet none have investigated how bluegrass invasions influence pollinator populations, which are a prominent conservation concern and provide ecosystem services. We measured the impact of bluegrass invasion on mixed-grass prairie forb and butterfly communities. Obligate grassland butterflies, those that rely on grasslands, decreased as bluegrass cover increased, including the threatened Hesperia dacotae. Conversely, the abundance of facultative grassland butterflies, those found in grasslands but not fully dependent on them for their life history, increased as bluegrass increased. Moreover, plant species diversity and flowering forb species richness decreased as bluegrass cover increased. Overall, bluegrass invasion led to butterfly and plant community simplification, signaling a loss of biodiversity and potentially ecosystem services. Our research is the first to quantify how grassland butterflies and the floral resources they depend on are negatively impacted by bluegrass invasion. Resource managers should adopt management strategies that reduce bluegrass cover and improve nectar and host resources for obligate grassland butterflies. Management choices that removed disturbance regimes inherent to the Northern Great Plains (i.e., fire and grazing) led to bluegrass dominance in the region. Therefore, restoring disturbance regimes may be one way to reduce bluegrass and benefit pollinator populations.  相似文献   

15.
王德利  王岭  韩国栋 《草业学报》2022,31(12):191-199
With the development of human understanding of the multi-functionality of grassland, coupled with the increasing demand for grassland ecological services, animal production and pastoral living, it is necessary to update the concept of grassland management, develop higher level livestock grazing and feeding technology based on multidisciplinary theories, and establish a more effective grassland grazing management paradigm. This study considers both the background and characteristics of the grassland resources and modern multi-dimensional social demands, and develops the concept of precise grassland grazing management which encompasses the versatility and stability of the grassland ecosystem and sustainability as the goal and the use of grassland science, animal science, ecology and other multi-disciplinary theories, based on the habitat conditions, especially the vegetation characteristics, livestock classes and their requirements, and livestock-vegetation interactions. Through multi-dimensional, effective and directional regulation of the livestock grazing process, the grassland management and utilization paradigm of synergistic balance between production and ecological functions can be finally realized. Also, the concepts and connotations of precise grazing and its relevant theoretical bases are systematically explained, including the plant compensatory growth mechanism, the intermediate disturbance hypothesis, the theory of diversifying grazing livestock, mechanisms of plant-animal interactions, nutrition regulation principles and versatility synergy. These concepts form a scientific basis for the regulation of grazing pressure and livestock assembly. In conjunction with this coverage, the key points in precision grazing are reviewed, such as dynamic optimal stocking rate(threshold), mixed grazing(species and proportion), remote sensing information options(satellite, unmanned aerial vehicle monitoring, large scale data processing)and other related supporting technologies. Finally, the authors sum up the concept of grassland multifunctionality as a goal of “combining productive function and ecological service in a win-win manner”, so providing a precise grazing management paradigm. This approach provides a principle for the integration of natural grassland grazing, grassland grazing with supplementary feeding, and drylot feeding, reflecting region-wide whole industry regulation of livestock grazing pressure/assembly and provision for animal nutrition, while aiming for grassland grazing systems to achieve an overall “livestock-vegetation balance”. Such a system will generate high quality animal products and sustainable ecological services. Precise grazing management of grassland is advanced, practical and extensive, and therefore is a desirable choice for future grassland management with great potential and prospect. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.  相似文献   

16.
韩枫  张志涛  张鑫  王建浩  王浩 《草业学报》2022,31(9):220-232
通过文献梳理的方式阐明了美国公共牧草地法治化管理进程,并以立法节点为依据,划分为应对草地退化、确立多用途利用与联邦所有制、调整放牧费制度、修正立法及完善政策4个阶段,详述了各阶段的矛盾冲突、治理目标及政策手段,并总结特征。研究发现,草地经历严重退化后,联邦政府积极治理,以立法确立了公有制下的多用途使用原则。法治进程中,分类管理、放牧费制度、公有制、土地资源调查、市场化探索贯穿始终,法治管理手段不断完善,形成了稳定的治理格局。从现代产权制度看,草原资源公有制对资本主义私有制国家亦是一种有效的产权管理探索形式,在私有草原之外,形成了相对完善的法理体系和有效的法治治理基础。尽管中美两国政治经济体制、产权结构不同,但美国公共牧草地管理历程依然为中国提供了较为丰富的经验借鉴,研究认为,中国应在草原国有的公有制原则下,强化草原生态环境保护的法治化;清查草地资源,实施产责明晰的分类分级管理,同时开展生态与民生效益监测;将草原生态补偿及草原重点生态工程纳入常规化法治管理;充分发挥市场作用,实现生态产品多元化供给。  相似文献   

17.
Experiments investigating grazing systems have often excluded ranch-scale decision making, which has limited our understanding of the processes and consequences of adaptive management. We conducted interviews and vegetation monitoring on 17 ranches in eastern Colorado and eastern Wyoming to investigate rancher decision-making processes and the associated ecological consequences. Management variables investigated were grazing strategy, grazing intensity, planning style, and operation type. Ecological attributes included the relative abundance of plant functional groups and categories of ground cover. We examined the environmental and management correlates of plant species and functional group composition using nonmetric multidimensional scaling and linear mixed models. After accounting for environmental variation across the study region, species composition did not differ between grazing management strategy and planning style. Operation type was significantly correlated with plant community composition. Integrated cow-calf plus yearling operations had greater annual and less key perennial cool-season grass species cover relative to cow-calf − only operations. Integrated cow-calf plus yearling ranches were able to more rapidly restock following drought compared with cow-calf operations. Differences in types of livestock operations contributed to variability in plant species composition across the landscape that may support diverse native faunal species in these rangeland ecosystems. Three broad themes emerged from the interviews: 1) long-term goals, 2) flexibility, and 3) adaptive learning. Stocking-rate decisions appear to be slow, path-dependent choices that are shaped by broader social, economic, and political dynamics. Ranchers described having greater flexibility in altering grazing strategies than ranch-level, long-term, annual stocking rates. These results reflect the complexity of the social-ecological systems ranchers navigate in their adaptive decision-making processes. Ranch decision-making process diversity within these environments precludes development of a single “best” strategy to manage livestock grazing.  相似文献   

18.
高寒草甸放牧生态系统研究现状   总被引：8，自引：7，他引：1  
综述了放牧强度对高寒草甸植物、动物和土壤的影响,说明放牧强度是影响家畜生产力、草场恢复力和稳定性的重要因素,也是影响土壤理化性质和土壤养分分布格局的关键因素;同时指出,高寒草地放牧系统受人为或气候等因素的影响而不断变化,影响的强度会改变整个系统的状态和变化趋势,即使是同一块草地,其负载能力和适宜放牧率(强度)也有所波动.因此,高寒草地放牧生态系统研究应以草场本身的条件和动态特征加以评价,应尽可能选择较多的气候和草场类型,应用动态规划和系统优化模型,对草地的持续生产和畜牧业的可持续发展进行动态模拟;建立草地放牧生态系统管理专家系统.  相似文献   

19.
基于多目标权重分析的草地适宜放牧率探讨   总被引：1，自引：1，他引：0  
依据生态系统服务的理念,首次发展了生态系统服务指数(ESI),试图通过对生态系统服务功能的综合考虑,提出科学的适宜放牧率的评价方法.本研究利用美国北达科他州立大学中部草原研究站17年长期放牧试验数据,选取植物多样性Shannon-Wiener指数、地上净初级生产力、土壤表层含水量和单位面积家畜增重4个指标,通过对不同指标分别赋予不同的权重,计算不同管理目标下ESI及其稳定性,并对单目标管理与多目标管理进行了比较研究.结果表明,对于北美混合普列里(Prairie)草地,围封不利用或建立自然保护区,虽然生态系统比较稳定,但既不能有效的提高植物多样性、初级生产力和土壤水分含量等生态功能,又没有畜产品产出;而在重牧或极重牧处理下虽然获得了较大的畜产品生产,但导致了草地生态系统的退化和较大的系统不稳定性.因此,这2种管理方式在实践中都是不可取的.应用生态系统服务指数综合考虑,认为应该权衡各项生态功能和生产功能,此时轻牧或中牧是最适宜的.因此,ESI的建立避免了单项指标的评价偏差,使得适宜放牧率的确定更加合理.  相似文献   

20.
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。  相似文献   

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