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1.
McNeely  J.A. 《Agroforestry Systems》2004,61(1-3):155-165

Many agroforestry systems are found in places that otherwise would be appropriate for natural forests, and often have replaced them. Humans have had a profound influence on forests virtually everywhere they both are found. Thus ‘natural’ defined as ‘without human influence’ is a hypothetical construct, though one that has assumed mythological value among many conservationists. Biodiversity is a forest value that does not carry a market price. It is the foundation, however, upon which productive systems depend. The relationship between agroforestry and the wild biodiversity contained in more natural forests is a complicated one, depending on the composition of the agroforestry system itself and the way it is managed. Complex forest gardens are more supportive of biodiversity than monocrop systems, shade coffee more than sun coffee, and systems using native plants tend to be more biologically diverse. Nonnative plants, especially potentially invasive alien species, threaten biodiversity and need to be avoided. The relationship between forests, agroforestry and wild biodiversity can be made most productive through applying adaptive management approaches that incorporate ongoing research and monitoring in order to feed information back into the management system. Maintaining diversity in approaches to management of agroforestry systems will provide humanity with the widest range of options for adapting to changing conditions. Clear government policy frameworks are needed that support alliances among the many interest groups involved in forest biodiversity.

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2.
全球人工林环境管理策略研究   总被引:1,自引:0,他引:1  
全球人工林为木材生产和缓解贫困做出了重要贡献, 在减缓和适应气候变化中起到了非常重要的作用。文中在介绍全球人工林资源的基础上, 分析了人工林对生物多样性、水分循环、养分循环和碳循环的影响和相互作用机制, 提出了人工林环境管理策略, 即建立人工林多功能经营制度、通过森林认证助推人工林可持续经营、充分利用REDD+机制提高人工林固碳效应的政策推动策略, 加强生物多样性保护、降低人工林对水循环负面影响、提高人工林的养分循环、促进人工林生态系统碳循环的生态系统完整性策略, 以及保育高保护价值区域策略和鼓励利益相关者参与人工林规划与管理策略。  相似文献   

3.
Land use and landscape changes, which have much effect on local biodiversity, are driven primarily by socioeconomic forces. Understanding these forces is important for preservation of current biodiversity. In this study, we clarified the socioeconomic forces that have brought about changes in the forest landscape around the Ogawa Forest Reserve in the southern Abukuma Mountains, Japan, by interviewing local residents and reviewing local historical documents. Furthermore, we reconstructed past forest landscapes and quantified the changes that have occurred from the beginning of the twentieth century until the present by use of old land-use maps and past aerial photographs. The use of forest resources has dramatically changed during the past hundred years, and it can be divided into three periods corresponding to the level of economic development. The main landscape has changed significantly from one mainly composed of expansive grasslands and broad-leaved forests into a mosaic of fragmented secondary forests and coniferous plantations. These landscape changes reflect shifts in both the use of forest resources by local residents and the management of the national forests. Clarifying temporal–spatial landscape changes by understanding the historical relationship between humans and the landscape provides useful information for optimizing conservation and management planning.  相似文献   

4.
Abstract

Tropical forests are very rich in biological diversity and form an important economic and ecological resource. This biodiversity is of great value for communities living in or near these forests as a ready source of subsistence and cash income, and for the world at large as a source of tropical timber and non-timber products and a repository of genetic and chemical information. However, this biological complexity is diminishing rapidly. We analyze the main human (anthropogenic) actions causing loss of tropical forest biodiversity along with the strategies of management for forest biodiversity. Not only is the biophysical component important in management for biodiversity, but the action participation and support of local people, the national government and international cooperation as a whole, arc essential for an effective and sustainable development of tropical forests. This integrated development strategy ensures that socio-economic and environmental benefits are provided for present and future generations.  相似文献   

5.
Abstract

Tropical forests are very rich in biological diversity and form an important economic and ecological resource. This biodiversity is of great value for communities living in or near these forests as a ready source of subsistence and cash income, and for the world at large as a source of tropical timber and non-timber products and a repository of genetic and chemical information. However, this biological complexity is diminishing rapidly. We analyze the main human (anthropogenic) actions causing loss of tropical forest biodiversity along with the strategies of management for forest biodiversity. Not only is the biophysical component important in management for biodiversity, but the active participation and support of local people, national governments, and the international community as a whole are essential to effective and sustainable development of tropical forests. This development strategy ensures that socioeconomic and environmental benefits are provided for present and future generations.  相似文献   

6.
The past decade has seen a global surge in forest management certification, with over 200 million hectares of the world's forest now certified as sustainably harvested. Because forests are some of the most species-rich environments on earth and more than 90% of the world's forests occur outside formal protected area systems, forest management certification will be one of the pervasive influences on global biodiversity for the foreseeable future. We find that current forest certification schemes are largely deficient because they fail to demand: (i) measurable management objectives for biodiversity, (ii) formal risk assessment of competing management options that integrate impacts on biodiversity, (iii) monitoring that directly addresses management performance requirements and a clear plan for how monitoring information will be used to make better management decisions, and (iv) ongoing research targeted toward practices that enhance biodiversity in managed landscapes. We argue that the credibility of certification schemes hinges on their ability to dictate scientifically defensible management systems for biodiversity conservation. We present a framework for adaptive risk management (ARM) of biodiversity that is both responsibly proactive and diligently reactive and recommend its incorporation in all certification schemes. We highlight the need for substantial government and agency investment in fostering ARM.  相似文献   

7.
Natural forces and anthropogenic activities greatly alter land cover,deteriorate or alleviate forest frag-mentation and affect biodiversity.Thus land cover and forest fragmentation dynamics have become a focus of concern for natural resource management agencies and biodiversity con-servation communities.However,there are few land cover datasets and forest fragmentation information available for the Dhorpatan Hunting Reserve (DHR) of Nepal to develop targeted biodiversity conservation plans.In this study,these gaps were filled by characterizing land cover and forest frag-mentation trends in the DHR.Using five Landsat images between 1993 and 2018,a support vector machine algorithm was applied to classify six land cover classes:forest,grass-lands,barren lands,agricultural and built-up areas,water bodies,and snow and glaciers.Subsequently,two landscape process models and four landscape metrics were used to depict the forest fragmentation situations.Results showed that forest cover increased from 39.4% in 1993 to 39.8% in 2018.Conversely,grasslands decreased from 38.2% in 1993 to 36.9% in 2018.The forest shrinkage was responsible for forest loss during the period,suggesting that the loss of for-est cover reduced the connectivity between forest and non-forested areas.Expansion was the dominant component of the forest restoration process,implying that it avoided the occurrence of isolated forests.The maximum value of edge density and perimeter area fractal dimension metrics and the minimum value of aggregation index were observed in 2011,revealing that forests in this year were most fragmented.These specific observations from the current analysis can help local authorities and local communities,who are highly dependent on forest resources,to better develop local forest management and biodiversity conservation plans.  相似文献   

8.
全球森林日益受到土地利用变化、分散化、管理目标变化和退化的影响。运用管理强度描述全球森林动态变化趋势,并概述了与森林管理相关的全球碳库变化。讨论了对“管理”的不同解释,并强调了一些重要的核算和分析问题。全球森林面积自1990 年以来下降了3%,但全球各地人工林面积都有所增加,截止2010 年已占全球森林面积的近7%。由于人为因素造成的栖息地破碎和退化,使得占所有林地34%的原始森林面积正在下降,尤其是南美洲和非洲。同时,自然再生林面积也有所下降。由于管理强度的增加,1990 年以来,非施业林面积(通常被定义为缺乏人类管理计划或保护状态的土地)大幅度下降,截止2010 年仅占全球森林的21%,而用于水土保持、生物多样性保护和提供生态系统服务等非木质林产品用地面积大幅增加。从全球来看,木材生产自1990 年以来一直相对稳定,但非木质林产品用地面积越来越多,表明林业采伐面积占森林总面积的比例较小。根据管理森林和区域研究领域的发展趋势可知,历史上和现在的森林管理是当前碳储量的一个非常重要的决定因素。目前,已建成的森林抵消了来自使用化石燃料释放二氧化碳的约30%,而减少森林的砍伐可能会将陆地碳地面总吸收量从大约4.0 t 升至每年6.2 t。然而,研究结果表明,多样化使用森林土地可能对维持或提高目前的陆地碳汇有重大影响。未来,诸如大气二氧化碳的增加和气候变化等间接的人类影响,以及土地管理的直接影响和木材生物燃料的日益增长的需求,都将成为影响土地管理战略规划和森林生态系统全球碳循环的重要因素。  相似文献   

9.
To halt biodiversity loss in the humid tropics of developing countries, it is crucial to understand the roles and effects of human-modified landscapes with fragmented forest remnants in maintaining biodiversity while fulfilling the demands of local communities and reducing poverty. To implement appropriate landscape planning for conserving biodiversity and ecosystem functioning, appropriate information is required about parameters of habitat suitability among various anthropogenic habitats with a range of distances to forests and vegetation characteristics, but such information is limited. We examined differences in avian communities between a remnant forest and four types of man-made forest (two mature plantations and two agroforests) in a forest–agricultural landscape of West Java, and we analyzed the effects of both local and landscape factors on various types of species richness in this landscape. The results from non-metric multidimensional scaling revealed avifauna in the two types of agroforest was clustered separately from that in the remnant forest, mainly because drastic declines in the abundance of forest specialists (including IUCN red-listed species) and their replacement with open-habitat generalists. The mixed-tree agroforests were colonized by 30 % of forest specialists and forest-edge species found in the remnant forest, and maintained the highest richness of species endemic to Indonesia among man-made forests, implying that some forest specialists and endemics might have adapted to ancient landscape heterogeneity. High proportion of insectivorous birds was found in the remnant forest (more than 50 %) and drastically decline in man-made forests, although the species richness of insectivores did not decline significantly in broad-leaved plantations. We concluded that protection of remnant forests should be prioritized to conserve forest bird diversity. However, as different environmental factors affected the richness values of different ecological groups, appropriate landscape design and habitat management could improve functional diversity in forest–agricultural landscapes in the tropics.  相似文献   

10.
The importance of structural complexity in forest ecosystems for ecosystem diversity has been widely acknowledged. Tree microhabitat structures as indicators of biodiversity, however, have only seldom been the focus of diversity research although their occurrence is highly correlated with the abundance of forest species and ecosystem functions. In this study, microhabitat structures in Douglas-fir (Pseudotsuga menziesii) forests were defined and their frequency and abundance in natural stands and stands of varying active management histories and stand ages was compared. Indicator microhabitat structures for natural forests were determined and the relationship of the abundance of microhabitat structures with tree diameter of Douglas-fir trees was analysed.  相似文献   

11.
With the increasing pressure to improve the contribution of forests to help dealing with global changes, it is critical to understand the different perceptions of those involved in the forest. How do forest owners, managers and members of local communities who often depend on the forest, value it and what are the problems affecting the forests in terms of being able to meet these new challenges?In Portugal, this task has taken on an even greater priority as more than 90% of the forest is private and forest management relies on the individual decisions of thousands of forest owners. To understand stakeholder views on forest and forest management, a transversal social perception survey was implemented in the form of a case study of central Portugal which included decision-makers, local technicians, forest owners and the general public.The results show that there is a consensus on the main issues affecting forests and forest management. A shift from classic forest owners to the emergence of indifferent forest owners was observed, although this shift has not been recognized by the forest owners in the survey, who maintain the individual management of their properties.  相似文献   

12.
Environmental functions of tropical forest can serve as criteria for forest conservation planning in the tropics. The objective of this study is to evaluate the environmental functions of tropical forest in Kinabalu Park, Sabah, Malaysia, using GIS and remote sensing techniques. Field data, statistical data, including weather data with geographic localities, maps and satellite image are collected. Linear regression models are developed for forests of different geological substrates, based on the relationships between altitude and biodiversity (Fisher’s alpha index). Biodiversity conservation function map is derived with the statistical models and a digital elevation model. Coupling with extensive literature review, an evaluation matrix for evaluating soil and water conservation functions including landslide prevention, flood prevention and drought prevention functions, is constructed. To evaluate the soil and water conservation functions, a weighted linear combination method is used with GIS layers of topography, geology, soil depth, rainfall and slope. Forest areas in Kinabalu Park are derived with land cover mapping using Landsat-TM image. Areas having high values of biodiversity conservation, flood and drought prevention functions are covered with mainly lowland rain forest. On the other hand, areas with high values of the landslide prevention function are covered with mainly subalpine forests. Using the environmental functions, a conservation index is computed to represent forests that are important to conservation. Based on theCI, the lowland rain forest receives highest priority in protection. In fact, it is located in the boundary areas of the park and thus exposed to illegal activities. This study would not be possibly accomplished without the map data as well as other data.  相似文献   

13.
森林生态系统是人类社会赖以生存的重要生态系统类型。然而,人类活动所引起的温室效应及其造成的全球气候变化对森林生态系统的负面影响正越来越引起全世界的关注。文中系统地阐述了全球气候变化事件对森林生态系统的植被分布、迁移趋势、适应能力、火灾状况、虫害爆发、木材产量和生物多样性等诸方面所产生的重要影响。另外,森林生态系统在减缓全球气候变化的过程中发挥着极为重要的作用。文中从森林可持续发展的角度系统地分析了应对气候变化应采取的森林可持续发展的相关策略与措施,并建议通过实时监控、及时防治、科学指导、全球合作等手段进一步增强森林生态系统的适应性和减缓全球气候变化的能力。  相似文献   

14.
Second-growth natural forests of roble–raulí–coihue are an important resource that must be managed from a multiple-use perspective. The objective of this work is to develop a thinning and harvest scheduling model for this type of forests aiming at maximizing profit while maintaining areas with minimum levels of biodiversity and landscape protection. The proposed model is based on a linear programming approach and incorporates constraints on timber yield flow and biodiversity levels as well as on clearcutting in high visibility areas. The evolution of forest diversity along the planning horizon has been modeled and both biodiversity and landscape indicators have been calculated. The model allows for the assessment of the physical and economic effects of management decisions, providing optimal resource allocation solutions for different scenarios and marginal values both for the land resource and for activities, such as biodiversity conservation or landscape protection, leading to the provision of non-market outputs.  相似文献   

15.
树种选择与配置对森林生态系统服务的影响   总被引:2,自引:1,他引:1  
我国森林面积和蓄积量连续增长,但造林树种单一、林分幼龄化、径级持续偏小、单位面积蓄积量低。在气候变化挑战及全球经济一体化大背景下,如何发挥森林在木材生产、生物多样性保护、固碳、涵养水源及社会文化等方面的多重服务功能以满足经济社会发展对森林的多元化需求,是我国现代林业建设的当务之急。文中通过梳理国内外相关文献,分析不同树种与配置模式和不同森林经营选择对森林生态系统服务的影响,以及对森林生态系统服务影响的模拟预测方法与工具,进而总结当前研究与实践的总体趋势,以期为我国树种选择及其优化配置、增强森林生态系统服务功能提供决策参考。  相似文献   

16.
Forests cover almost 30% of the Mediterranean region today, yet forest management activities have influenced structure and composition of both natural and planted forests. To date no study has been conducted to evaluate the impact of forest management on saproxylic beetle assemblages, although it is known that the Mediterranean is a biodiversity hotspot with a long-lasting human pressure on natural habitats. We provide an overview of saproxylic beetle assemblages of three forest types (mature Pinus halepensis forests, mature Pinus brutia forests, young Quercus calliprinos forests) in the East Mediterranean region using a one-year sample from 12 forest plots located in the north of Israel.  相似文献   

17.
随着全球热带雨林面积的急剧减少,对热带林的经营管理日益得到人类的关注。雷达系统以其全天侯、全天时、穿透性等功能成为支持森林可持续经营中信息采集的重要工具。文中介绍了用现有技术做雷达影像分析,以及这些技术应用于全球水平、国家水平和森林经营单位水平的森林资源评价和森林资源监测的潜力。  相似文献   

18.
19.
The potential for traditional and local ecological knowledge to contribute to biodiversity conservation has been widely recognized, but the actual application of this knowledge to biodiversity conservation is not easy. This paper synthesizes literature about traditional and local ecological knowledge and forest management in the Pacific Northwest to evaluate what is needed to accomplish this goal. We address three topics: (1) views and values people have relating to biodiversity; (2) the resource use and management practices of local forest users, and their effects on biodiversity; (3) models for integrating traditional and local ecological knowledge into biodiversity conservation on public and private lands. We focus on the ecological knowledge of forest users belonging to three groups who inhabit the region: American Indians, family forest owners, and commercial nontimber forest product harvesters.  相似文献   

20.
Tropical deforestation in the Asia-Pacific Region has accelerated in Lhe last decade, seriously depleting the forest resource base. Most forest loss results from agricultural clearing, but is generally preceded by forest degradation from destructive logging (Southeast Asia) or overuse of forest resources (South Asia). Tropical forests are highly variable, requiring a system of classification to guide management objectives; one such system is ecological life zone mapping. Forestry operations should reflect the need for both conservation and production. Most Asia-Pacific forests are managed on variations of a selection system. Logging damage is the most important forestry-sector threat to commercial forestry, reducing both future timber production and the availability of non-timber products. The short duration of logging concession agreements, nontransferability of concession contracts, and undervaluation of forest resources all contribute to forest "mining" practices. Alternative forest management methods exist: logging damage can be substantially reduced at little or no additional cost; small-scale mobile sawmills can increase local incomes while reducing the need for skidding; and Assisted Natural Regeneration can facilitate the reforestation of denuded lands. The best hope for sustainable use of forest resources lies with those who must live with the consequences of forest mismanagement. Local involvement in foresy planning, implementation and enforcement is essential. Successful forest management projects depend on the judgement of field-based personnel familiar with the forests, cultures and institutions of each country, working in cooperation with local forestry experts and forest-dependent people.  相似文献   

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