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1.
The wood pastures or hardwood rangelands of the southwestern Iberian Peninsula are complex social-ecological systems created from the long-term interaction of society and the landscape. Dehesa, oak woodlands managed for grazing, cropping, and other forms of production, is the most common rangeland system and one of the most distinctive landscapes. Traditionally characterized by multifunctional low-intensity management that enhances a wide range of ecosystem services, current management has shifted from the traditional toward more intensified models. This paper assesses the coproduction of ecosystem services on dehesa properties by exploring the relationship between biophysical and sociocultural factors and dehesa management practices. Based on 42 surveys we analyze 16 quantitative indicators using multivariate techniques. The results indicate that there are four main dehesa types as defined by their characteristics and management: large heterogeneous operations with diverse products; small and homogeneous operations focused on a reduced number of products; medium-large properties focused on crop production; and midsized properties with easy public access. Management is the result of the dynamics of interacting biophysical and sociocultural factors that influence manager priorities and investments. Management decisions group around the degree of multifunctionality of the operation, the relative importance of crop production, the degree of grazing pressure in the system, and how restrictive public access policy is. We find that in the study area, interactions between all the previously mentioned elements covary consistently, generating bundles of ecosystem services associated with each of three management models based on the intensity of management.  相似文献   

2.
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   

3.
Crossing disciplinary boundaries, particularly between social and ecological sciences, challenges those seeking to contribute to solving complex and multidimensional environmental problems on rangelands. In this Special Issue we present a set of 13 papers that to varying degrees attempt to integrate, or bring together, diverse approaches across disciplines to understand silvopastoral systems. The papers are about rangelands in numerous countries and regions, including Spain, Estonia, Greece, Germany, Hungary, Italy, Portugal, Romania, the United States, Latin America, and Sweden. Silvopastoral systems provide ecosystem goods and services important to communities, cultures, and society. Management deliberately exploits the diversity fostered by rangeland systems that mix woody species with a well-developed herbaceous understory, offering a greater diversity of products, species, vegetation structural characteristics, and habitat components than either grassland or forest. Biodiversity often peaks at the intermediate levels of tree and shrub cover characteristic of silvopastoral systems. We introduce the papers grouped by four overarching topics: 1) typologies and scales, 2) social-ecological interactions, 3) integrated management, and 4) multiple knowledge systems. Unfortunately, silvopastoral systems often run afoul of ongoing intensification and simplification trends in agricultural production that reduce their economic and ecological resilience. Privately owned systems, the most common in this issue, are subject to the need for owner income. Finding ways to support the benefits of these systems for the public is difficult, as management traditions must be conserved as well as the land. We hope this issue illustrates the value of multifunctional systems and offers insights into how they work.  相似文献   

4.
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   

5.
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   

6.
This paper analyzes rancher participation in conservation programs in the context of a social-ecological framework for adaptive rangeland decision-making. We argue that conservation programs are best understood as one of many strategies of adaptively managing rangelands in ways that sustain livelihoods and ecosystem services. The framework hypothesizes four categories of variables affecting conservation program participation: operation/operator characteristics, time horizon, social network connections, and social values. Based on a mail survey of California ranchers, multinomial logit models are used to estimate the impact of these variables on different levels of rancher involvement in conservation programs. The findings suggest that ranchers with larger amounts of land, an orientation towards the future, and who are opinion leaders with access to conservation information, are more likely to participate in conservation programs.  相似文献   

7.
The social and ecological contexts for rangeland management are changing rapidly, prompting a reevaluation of science, management, and their relationship. We argue that progression from steady-state management to ecosystem management has served the rangeland profession well, but that further development toward resilience-based management is required to ensure that ecosystem services are sustained in an era of rapid change. Resilience-based management embraces the inevitability of change and emphasizes that management should seek to guide change to benefit society. The objectives of this forum are to: 1) justify the need for adopting resilience-based management, 2) identify the challenges that will be encountered in its development and implementation, and 3) highlight approaches to overcoming these challenges. Five grand challenges confronting the adoption of resilience-based management, based upon the insights of 56 rangeland researchers who have contributed to this special issue, were identified as: 1) development of knowledge systems to support resilience-based management, 2) improvement of ecological models supporting science and management, 3) protocols to assess and manage tradeoffs among ecosystem services, 4) use of social-ecological system models to integrate diverse knowledge sources, and 5) reorganization of institutions to support resilience-based management. Resolving the challenges presented here will require the creation of stronger partnerships between ecosystem managers, science organizations, management agencies, and policymakers at local, regional, and national scales. A realistic near-term goal for achieving such partnerships is to initiate and support collaborative landscape projects. The creation of multiscaled social learning institutions linked to evolving knowledge systems may be the best approach to guide adaptation and transformation in rangelands in the coming century.  相似文献   

8.
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   

9.
Europe’s woodland and savanna rangelands, often part of silvopastoral systems known as wood-pastures, are deteriorating because of abandonment that leads to return to a forested state or lack of tree regeneration from overgrazing or tree and shrub removal. Despite numerous local studies, there has been no broader survey of the stand structure of European wood-pastures showing which systems are at risk of losing their semiopen character. This overview aims to 1) show some of the differences and similarities in wood-pastures from landscapes across Europe and 2) identify which of these wood-pastures are at risk of losing their semiopen character. We collated a dataset of 13 693 trees from 390 plots in wood-pastures from eight different European regions (western Estonia, eastern Greece, northern Germany, Hungary, northern Italy, southern Portugal, central Romania, and southern Sweden), including tree diameters at breast height, tree density, management type, and tree species composition. On the basis of their structural characteristics, we classified wood-pastures using principal component analysis (PCA) and cluster analysis. The PCA showed a gradient from dense wood-pastures with high levels of regeneration (e.g., in Estonia) to sparse wood-pastures with large trees but a lack of regeneration (e.g., in Romania). Along this gradient, we identified three main groups of wood-pastures: 1) sparse wood-pastures with mostly big trees; 2) dense wood-pastures composed of small trees, and 3) wood-pastures containing a wide range of tree ages. Our results show a large structural gradient in European wood-pastures, as well as regeneration problems varying in their severity, highlighting the importance of social-ecological context for wood-pasture conditions. To maintain the ecological and cultural integrity of European wood-pastures, we suggest 1) more comprehensively considering them in European policies such as the Common Agricultural Policy and EU Habitats Directive, while 2) taking into account their structural characteristics and social-ecological backgrounds.  相似文献   

10.
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   

11.
Leaf area index (LAI) is defined as the one-sided area of leaves above a unit area of ground. It is a fundamental ecosystem parameter that is a required input of process-based plant growth and biogeochemical models. Direct measurement of LAI is the most accurate method, but is destructive, time-consuming, and labor-intensive. LAI is highly variable in time and space on sagebrush-steppe rangelands, and a rapid, nondestructive method is desirable to understand ecosystem processes. The point-intercept method is nondestructive and has been demonstrated to provide accurate LAI estimates, but the method is time-consuming. LAI measurement with the Accupar ceptometer (Decagon Devices, Pullman, WA) is nondestructive and faster than the point-intercept method, but has not been evaluated on sagebrush-steppe rangelands. The objective of this study was to evaluate the ceptometer for measurement of LAI in sagebrush-steppe rangelands. Ceptometer and point-intercept LAI data were collected at six sites in sagebrush-steppe rangelands and the values were compared. We found that 1) ceptometer LAI data were consistently greater than point-intercept LAI data, 2) ceptometer data were much more variable than the point-intercept data based on standard deviations, and 3) the overall correlation between the two methods was very weak (r2 = 0.15). The much greater ceptometer LAI values were, at least partly, due to the large woody component of the vegetative cover. We attribute the high variability of ceptometer-measured LAI to high instrument sensitivity of the angle of the instrument relative to the sun.  相似文献   

12.
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   

13.
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   

14.
More diverse sources of energy are needed for countries to progress toward energy independence and to meet future food production needs. The US Task Force on Strategic Unconventional Fuels concluded that to achieve this objective it is essential to develop a domestic unconventional fuels industry. Rangelands, which cover 50% to 70% of the earth's terrestrial surface and dominate much of the western half of the United States, represent a major source of alternative energy resources. A framework to systematically identify biophysical-socioeconomic links that influence the delivery of ecosystem services affected by alternative uses of rangelands has been lacking. The Integrated Social, Economic, and Ecological Conceptual framework was developed by the Sustainable Rangeland Roundtable to address this deficiency. We apply this framework to demonstrate how the effect on ecosystem services of exploiting rangeland-based biofuel, natural gas, and wind energy resources can be systematically compared. We also demonstrate the use of this framework for selecting suitable indicators to monitor changes in the biophysical-socioeconomic links affected by the development of these unconventional energy sources. This type of approach can potentially enhance coordination between federal, state, and local agencies that are attempting to set polices and regulations for the sustainable development of unconventional energy resources on rangelands.  相似文献   

15.
Recent climatic trends and climate model projections indicate that climate change will modify rangeland ecosystem functions and the services and livelihoods that they provision. Recent history has demonstrated that climatic variability has a strong influence on both ecological and social components of rangeland systems and that these systems possess substantial capacity to adapt to climatic variability. Specific objectives of this synthesis are to: 1) evaluate options to mitigate greenhouse gas emissions and future climate change; 2) survey actions that individuals, enterprises, and social organizations can use to adapt to climate change; and 3) assess options for system transformation when adaptation is no longer sufficient to contend with climate change. Mitigation for carbon sequestration does not appear economically viable, given the small and highly variable carbon dioxide fluxes of rangeland ecosystems and the high transaction costs that would be incurred. In contrast, adaptation strategies are numerous and provide a means to manage risks associated with climate change. Adaptation strategies are diverse, including altered risk perception by individuals, greater flexibility of production enterprises, and modifications to social organizations that emphasize climatic variability, rather than consistency. Many adaptations represent “no regrets” actions because their implementation can be justified without emphasis on pending climate change. Adaptations specific to livestock production systems can include flexible herd management, alternative livestock breeds or species, innovative pest management, modified enterprise structures, and geographic relocation. Social-ecological systems in which adaptation is insufficient to counter the adverse consequences of climate change might undergo transformative change to produce alternative ecosystem services, production enterprises, and livelihoods. The rangeland profession is in a pivotal position to provide leadership on this global challenge because it represents the intersection of management and scientific knowledge, includes diverse stakeholders who derive their livelihoods from rangelands, and interacts with organizations responsible for rangeland stewardship.  相似文献   

16.
Knowledge of herbivory tolerance of dominant plant species and their responses to varying grazing intensity is required for sustainable grazing management in semiarid rangeland ecosystems. In a field experiment, we studied the effects of simulated grazing 0%, 30%, 50%, and 80% leaf removal (control, partial, intermediate, and heavy leaf removal) of three dominant perennial legumes: Astragalus cyclophyllon, Astragalus effuses, and Hedysarum criniferum in semiarid rangelands of southwestern Iran for 2 yr and tested 1) differential herbivory tolerance in terms of regrowth ability of belowground and aboveground biomass (AGB), fecundity, and nonstructural carbohydrate reserves; and 2) trade-off between forage quantity and quality—less defoliated plants produce larger amount of biomass with less forage quality and vice versa. The results showed a reduction in AGB and reproduction in each of the three plants. However, three forbs exhibited some sort of variations in shoot and root growth, reproduction and forage quality under intermediate and heavy leaf removal. Leaf removal in individuals of A. effusus and H. criniferum are more likely to compensate for tissue loss by allocating the available resources to the expansion of root biomass, at the cost of AGB and reproductive effort. Leaf removal also led to an increase in forage quality in each of the three forb species, depending on the level of height removal. The control plant had a higher amount of biomass production and lower amount of crude protein compared with heavy leaf removal treatments (i.e., 80%), by contrasting responses of acid detergent fiber and neutral detergent fiber, indicating a trade-off between forage quality and forage quantity. The results indicate that there is a balance among forage quantity, quality, and regrowth ability of belowground and aboveground tissues in intermediate leaf removal treatments of these forb species. This balance is used to develop principles for grazing management of steppe rangelands because such a regime meets different criteria including forage quantity, quality, and nonstructural carbohydrate reserves.  相似文献   

17.
环青海湖地区天然草场牦牛的环境容纳量   总被引：1，自引：0，他引：1  
由于长期过牧所造成的环青海湖地区天然草场退化一一直是一个困扰该地区牦牛业可持续发展的重要因素。本研究通过对该地区草原生产系统蛋白质平衡进行研究，获得了该地区生态系统中牦牛的精确合理的环境容纳量。  相似文献   

18.
Private landowners are often de facto stewards of biodiversity and ecosystem services. In California's Sierra Nevada foothills, ranchers frequently present the only defense against biological invasions in private rangelands. Although ranchers' land management goals (e.g., the desire to control invasive species) can be consistent with ecosystem protection, practical constraints often limit their success. Considerable research on the invasive weed, yellow starthistle (Centaurea solstitialis L.), has produced numerous control strategies. Nevertheless, the range of this noxious weed continues to increase. We used surveys and interviews to document the weed control efforts of 202 ranchers and to identify practical limitations to their efficacy. Overall, 86% of ranchers who had experienced yellow starthistle infestation had attempted control, using one or more of 19 methods. Early response reduced negative effects from yellow starthistle. Control methods learned from agricultural advisors were reported more effective than those learned elsewhere. Limitations to yellow starthistle control in our study population resulted from incomplete information regarding control methods, complexity of weed control in heterogeneous landscapes, inconsistent application of methods, and lack of long-term planning for weed control. Such hindrances make it difficult for landowners to implement control methods promoted by researchers. This gap between science and practice contributes to the continued increase of yellow starthistle within the study region. To shrink this gap, researchers and agricultural advisors can incorporate environmental heterogeneity into applied agricultural research, use land stewards' knowledge and experience, and increase public education.  相似文献   

19.
Globally, new combinations of introduced and native plant and animal species have changed rangelands into novel ecosystems. Whereas many rangeland stakeholders (people who use or have an interest in rangelands) view intentional species introductions to improve forage and control erosion as beneficial, others focus on unintended costs, such as increased fire risk, loss of rangeland biodiversity, and threats to conservation efforts, specifically in nature reserves and parks. These conflicting views challenge all rangeland stakeholders, especially those making decisions on how best to manage novel ecosystems. To formulate a conceptual framework for decision making, we examined a wide range of novel ecosystems, created by intentional and unintentional introductions of nonnative species and land-use–facilitated spread of native ones. This framework simply divides decision making into two types: 1) straightforward–certain, and 2) complex–uncertain. We argue that management decisions to retain novel ecosystems are certain when goods and services provided by the system far outweigh the costs of restoration, for example in the case of intensively managed Cenchrus pastures. Decisions to return novel ecosystems to natural systems are also certain when the value of the system is low and restoration is easy and inexpensive as in the case of biocontrol of Opuntia infestations. In contrast, decisions whether to retain or restore novel ecosystems become complex and uncertain in cases where benefits are low and costs of control are high as, for example, in the case of stopping the expansion of Prosopis and Juniperus into semiarid rangelands. Decisions to retain or restore novel ecosystems are also complex and uncertain when, for example, nonnative Eucalyptus trees expand along natural streams, negatively affecting biodiversity, but also providing timber and honey. When decision making is complex and uncertain, we suggest that rangeland managers utilize cost–benefit analyses and hold stakeholder workshops to resolve conflicts.  相似文献   

20.
通过对山西省暖性草丛类、暖性灌草丛类、温性草原类、温性山地草甸类4类主要天然草地的70个大样地进行调查,测定草地地上、地下生物量,分析4个海拔梯度,6个纬度梯度和5个经度梯度的生物量变化规律,旨在掌握山西天然草地生物量的空间分布特征,为充分了解山西草地生态系统及合理利用奠定基础。结果表明,山西省主要类型天然草地生物量随海拔的升高呈现出先升高后降低的趋势,海拔1 200-1 600 m的地下生物量和总生物量最高,分别为1 412.86和2 037.87g·m~(-2);而地上活体生物量和凋落物生物量则是在800m的海拔处最高,分别为301.5和105.97g·m~(-2)。随纬度从南向北地下生物量和总生物量呈先增加后降低的趋势,且南边略高于北边(P0.05)。随经度从西向东地下生物量和总生物量呈先增加后降低再增加的趋势。不同草地类型地上生物量存在较大差异,暖性草丛类草地的地上活体生物量显著高于其余3类草地类型(P0.05)。暖性草丛类和温性山地草甸类草地的凋落物生物量显著高于暖性灌草丛类和温性草原类草地(P0.05)。  相似文献   

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