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Prospects for conserving biodiversity in Amazonian extractive reserves   总被引:1,自引:0,他引:1  
Non‐timber forest product (NTFP) extraction is a popular alternative to timber extraction that figures prominently in efforts to utilize tropical forests sustainably. But the ability to conserve biodiversity through NTFP management, particularly in extractive reserves in Amazonia, has remained untested. We found that intensive management of Euterpe oleracea (Palmae) fruit, one of the most important extractive products in the Amazon, has substantial impacts on biodiversity, whereas moderate management does not. We mimicked traditional levels of fruit harvest in a replicated experiment over one fruiting season. High‐intensity harvest (75% of fruits removed) reduced avian frugivore species diversity by 22%. Low‐intensity harvest (40% of fruits removed), however, had no effect on diversity. On a larger scale, we found that forests with enriched densities of E. oleracea supported more fruit‐eating birds but fewer non fruit‐eating birds than non‐enriched forests. Taken together, these results suggest that intensive NTFP management to meet market demands may trigger substantial ecological impacts, at least at the level of our study. E. oleracea harvest should be limited where conservation of biodiversity is a goal.  相似文献   

3.
The Knuckles range of forests has been identified as a unique biological resource in Sri Lanka with much biodiversity. It is also important as a watershed which feeds the Mahaweli reservoir system. Having considered the present hazardous land-use practices such as cardamum production and shifting cultivation, the Knuckles range has been declared a national wilderness area. The Forest Department is in the process of preparing the management plan for the area. There are about 48 villages in the vicinity of the forest. This study attempts to estimate the composition of income in the peripheral communities, ticularly the extraction of non-timber forest products (NTFP) from this range of forests. Data were collected using structured questionnaires from 60 households in three villages in the vicinity of the forest. The rural economy is described using a farming systems approach and the net income contributed by each activity in the farming system was estimated. Results show that nine components of the farming system use resources from the village and the forest, with at least 47 plant species used by the villagers for different purposes. Cardamum production and shifting cultivation contribute significantly to the total income of the household, but the majority of households in the study depend upon forest resources to supply some portion of their income. Nevertheless, the monetary value of the annual income generated by NTFP is much lower than income from either cardamum production or shifting cultivation. If cardamum production and shifting cultivation are to be restricted under the conservation program, there could be additional pressure put on NTFP. Therefore, we suggest a study of the natural regen-eration capacity of selected NTFP; such information should be used in finalizing the management plan in the Knuckles range of forests.  相似文献   

4.
A persisting problem in protected area management in Nepal is whether resources from buffer zones can replace villagers' extraction of resources from protected areas. Community forestry is assigned a major role in supplying these substitutes, and natural regeneration and rehabilitation of degraded forests are thought to be means to establish forests with a high compatibility with villagers' demand. This study investigates the structure and floristic composition of six community forests established through natural regeneration of degraded sal (Shorea robusta) forests and of former riverine forest areas which have been cleared and overgrazed. The inventories are compared to an in-depth survey of the extraction of forest products from Royal Chitwan National Park (RCNP) for 12 consecutive months by nine households. The results show that natural regeneration creates a multi-layered forest structure and that early succession stages of mixed forests, which floristically resemble former primary forests, emerged in only a few years when protected from grazing. The presence of timber and fuelwood species in the community forest matched to some extent the species traditionally extracted by people from the Park. With regard to non-timber forest products (NTFP), the natural regenerated community forests were much less compatible with the villagers' traditional dependency on and extraction from the Park, which points to the limitations of community forestry in relieving anthropogenic pressure on the RCNP.  相似文献   

5.
Comparisons between two forest localities were undertaken to assess the potential availability of non-timber forest products (NTFPs) within the low-diversity forests of Guyana. Information on the abundance and distribution of tree species, and local and national ethnobotanical surveys were used classifying species into five categories (timber, construction, technological, edible and medicinal). A total of 152 species were recorded from the two localities; covering 236 different uses, 33 known commercial timber species and 106 species with potential non-timber product utilization. The most important plant families with the highest number of uses at both localities were Leguminosae (sub-families Caesalpinioideae and Mimosoideae), Arecaceae, Bombacaceae and Chrysobalanaceae, although these families were not the most abundant families at both localities. At both forest localities eight tree species represented over 50% of all the trees. At Kurupukari three species, each with more than three identified NTFPs, represented over 20% of the trees.Potential utilization of NTFPs are discussed in accordance with species richness, tree density, the number of different uses per species, and the percentage of trees represented by each utilizable species. Considering the constraints on the future potential commercialization of NTFPs, two scenarios for the extraction of NTFPs are discussed. Within relatively species-rich forest types the high diversity of products provides potentially viable multiple-species extractionism. In contrast, in low-diversity forest types, typical of the Guiana Shield, one or two NTFP species frequently represent over 50% of the canopy trees, and therefore substantially increase the potential sustainable extraction for single-species harvesting. It is suggested that these low-diversity types of forest are prioritized for conservation on the basis of ensuring future utilization, refuge, of non-timber forest products.  相似文献   

6.
Non-timber forest products (NTFP) represent culturally and economically important resources for millions of people worldwide. Although many NTFP are harvested from disturbed habitats and therefore subject to multiple pressures, few quantitative studies have addressed this issue. Similarly few NTFP studies have assessed seasonal variation in demographic rates even though this can confound harvest effects. In Hawaiȁ8i, the wild-gathered ferns, Microlepia strigosa and Sphenomeris chinensis, represent highly important cultural resources but declining populations have led to conservation concerns. Both ferns are harvested from disturbed, alien-dominated forests and contemporary Hawaiian gathering practices often consist of harvest and concurrent weeding of alien invasive species. We assessed the effects of concurrent frond-harvest and alien species weeding on frond structure, density, and rates of production by comparing experimentally harvested vs. control plots, and documented relationships between frond demographic patterns and precipitation. Gathering practices had no impact on frond density of either species or on most other demographic parameters over the short term. Exceptions included a significant decrease in the density of the longest S. chinensis fronds and a significant decrease in M. strigosa frond production when fronds were gathered without alien weeding. However, seasonal and annual changes in frond density and production occurred across all plots of both species and were significantly correlated with precipitation. The relatively low harvest effects for both species are likely due to several factors including short frond longevity and the strict criteria used by gatherers to select harvestable fronds. The potential for sustainable harvest in the context of alien-dominated forests is discussed.  相似文献   

7.
Sustainable extraction of non-timber forest products (NTFPs) has recently gained considerable attention as a means to enhance rural incomes and conserve tropical forests. However, there is little information on the amounts of products collected per unit area and the impact of extraction on forest structure and composition. In this paper we estimate the quantities of selected products gathered by the Soligas, the indigenous people in the Biligiri Rangaswamy Temple (BRT) sanctuary in Karnataka, India, and examine the effect of extraction on forest structure and composition. Two sites, distant (DS) and proximal (PS), were identified based on the proximity to a Soliga settlement. The frequency of different size classes indicates that regeneration overall is poor in the area. The two sites show differences in species richness, basal area, and tree mortality. Furthermore, non-timber forest product species show a greater deficit of small size classes than the timber forest species, suggesting that regeneration is affected by collection of seeds and fruits from non-timber forest product species. Regeneration, however, may also be affected by other anthropogenic pressures such as fire, grazing and competition with weeds.  相似文献   

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9.
Lowland and mid-elevational rainforests of Sri Lanka harbor a relict, endemic-rich flora which is also rich in timber and non-timber forest resources. These forests supply nearly half the total wood requirements of the country and are dwindling rapidly; management of the forests to conserve the biological richness and maintain environmental services is therefore a difficult proposition. This predicament is further compounded by the dependency of rural people on a range of non-timber forest resources for their subsistence and income. A forestry master plan recently prepared for Sri Lanka has not given adequate recognition to the important role played by non-timber forest resources in rural livelihood. This oversight is primarily due to the lack of quantitative information to justify the role of non-timber forest resources in forestry sector development. Forestry policies that ignore these resources often anger local people, leading the villagers to vent their disapproval through destructive actions such as burning timber plantations. Long-term interdisciplinary research in ecology, reproductive and soil biology, ethnobiology, silviculture, rural sociology and resource economics in progress at Sinharaja attempts to address these questions of sustainable development of forest resources in an integrated mode. While research oriented toward conservation investigates both short- and long-term ecosystem dynamics in natural and modified forest stands, utilization-oriented research probes the impact of increased human disturbance, particularly the impact of rural communities on dwindling forest resources, as well as the effect of forest conservation on rural livelihood. These studies continue to seek alternative methods of forest management which are socially acceptable, economically viable, and ecologically sustainable for multiple uses. These methods will assist in the refinement of current forest policies, forestry planning, and the implementation of new policies and plans in Sri Lanka.  相似文献   

10.
Shifting cultivation is a widespread practice in tropical forested areas that policy makers often regard as the major cause of forest degradation. Secondary fallow forests regrowing after shifting cultivation are generally not viewed as suitable for biodiversity conservation and carbon retention. Drawing upon our research in the Philippines and other relevant case studies, we compared the biodiversity and carbon sequestration in recovering secondary forests after shifting cultivation to other land uses that commonly follow shifting cultivation. Regenerating secondary forests had higher biodiversity than fast growing timber plantations and other restoration options available in the area. Some old plantations, however, provided carbon benefits comparable the old growth forest, although their biodiversity was less than that of the regenerating forests. Our study demonstrates that secondary forests regrowing after shifting cultivation have a high potential for biodiversity and carbon sequestration co‐benefits, representing an effective strategy for forest management and restoration in countries where they are common and where the forest is an integral part of rural people's livelihoods. We discuss the issues and potential mechanisms through which such dynamic land use can be incorporated into development projects that are currently financing the sustainable management, conservation, and restoration of tropical forests.  相似文献   

11.
Harvesting wild plants for non-timber forest products (NTFPs) can be ecologically sustainable–without long-term consequences to the dynamics of targeted and associated species–but it may not be economically satisfying because it fails to provide enough revenues for local people over time. In several cases, the same species can be harvested for NTFP and also logged for timber. Three decades of studies on the sustainability of NTFP harvest for local people’s livelihood have failed to successfully integrate these socio-economic and ecological factors. We apply optimal control theory to investigate optimal strategies for the combinations of non-lethal (e.g., NTFP) and lethal (e.g., timber) harvest that minimize the cost of harvesting while maximizing the benefits (revenue) that accrue to harvesters and the conservation value of harvested ecosystems. Optimal harvesting strategies include starting with non-lethal NTFP harvest and postponing lethal timber harvesting to begin after a few years. We clearly demonstrate that slow growth species have lower optimal harvesting rates, objective functional values and profits than fast growth species. However, contrary to expectation, the effect of species lifespan on optimal harvesting rates was weak suggesting that life history is a better indicator of species resilience to harvest than lifespan. Overall, lethal or nonlethal harvest rates must be <40 % to ensure optimality. This optimal rate is lower than commonly reported sustainable harvest rates for non-timber forest products.  相似文献   

12.
Studies on the ecological impacts of non‐timber forest products (NTFP) harvest reveal that plants are often more resilient to fruit and seed harvest than to bark and root harvest. Several studies indicate that sustainable fruit harvesting limits can be set very high (>80% fruit harvesting intensity). For species with clonal and sexual reproduction, understanding how fruit harvest affects clonal reproduction can shed light on the genetic risks and sustainability of NTFP harvest. We studied 18 populations of a gallery forest tree, Pentadesma butyracea (Clusiaceae), to test the impact of fruits harvest, climate and habitat size (gallery forest width) on the frequency of sexual or clonal recruitment in Benin, West Africa. We sampled populations in two ecological regions (Sudanian and Sudano‐Guinean) and in each region, we selected sites with low, moderate and high fruit harvesting intensities. These populations were selected in gallery forests with varying width to sample the natural variation in P. butyracea habitat size. Heavily harvested populations produced significantly less seedlings but had the highest density and proportion of clonal offspring. Our study suggests that for plant species with dual reproductive strategy (via seeds and clonal), fruit harvesting and associated disturbances that come with it can lead to an increase in the proportion of clonal offspring. This raises the issue that excessive fruit harvest by increasing the proportion of clonal offspring to the detriment of seed originated offspring may lead to a reduction in genetic diversity with consequence on harvested species capability to withstand environmental stochasticity.  相似文献   

13.
Mangrove forests of Tanzania are reserved by law, but the capacity to effectively enforce this institution has remained far from reach and mangrove forests continue to be exploited as cheap sources of wood and forest land for other uses. Often, the rural poor who depend on mangroves for their subsistence are pointed out by the state institutions as culprits of the degradation. Promisingly though, this paradigm is being offset by the emerging positive view about human proclivity for caring and nurturing common resources. Traditional and community based forest management practices are emerging as appropriate alternatives to state control and institutional arrangement for ensuring sustainable management of forest resources. Nonetheless, community based management has not yet been robustly implemented for mangrove forests in Tanzania. Retrospectively, this paper argues that nationalization of mangrove forests has not been successful in reversing mangrove degradation. The experiences have instead been the frictions between people and the state, as desperate rural poor continue to plunder on and make a living at the expense of mangrove forests. The paper exemplify how policy failure, weak or dysfunctional state institutions in Tanzania compounded by little participatory awareness and self commitment are ruining the restoration and conservation initiatives.  相似文献   

14.
Forests provide a wide variety of ecosystem services (ES) to society. The boreal biome is experiencing the highest rates of warming on the planet and increasing demand for forest products. To foresee how to maximize the adaptation of boreal forests to future warmer conditions and growing demands of forest products, we need a better understanding of the relative importance of forest management and climate change on the supply of ecosystem services. Here, using Finland as a boreal forest case study, we assessed the potential supply of a wide range of ES (timber, bilberry, cowberry, mushrooms, carbon storage, scenic beauty, species habitat availability and deadwood) given seven management regimes and four climate change scenarios. We used the forest simulator SIMO to project forest dynamics for 100 years into the future (2016–2116) and estimate the potential supply of each service using published models. Then, we tested the relative importance of management and climate change as drivers of the future supply of these services using generalized linear mixed models. Our results show that the effects of management on the future supply of these ES were, on average, 11 times higher than the effects of climate change across all services, but greatly differed among them (from 0.53 to 24 times higher for timber and cowberry, respectively). Notably, the importance of these drivers substantially differed among biogeographical zones within the boreal biome. The effects of climate change were 1.6 times higher in northern Finland than in southern Finland, whereas the effects of management were the opposite—they were three times higher in the south compared to the north. We conclude that new guidelines for adapting forests to global change should account for regional differences and the variation in the effects of climate change and management on different forest ES.  相似文献   

15.
Pakistan′s forest resource base is mostly found in the mountains of the North-West Frontier Province (NWFP) supporting the livelihood of the rural poor and providing different ecological services. The present study was, therefore, initiated with the aim to evaluate different constraints and opportunities for sustainable livelihoods and cash income generation from NTFPs in the mountainous area of NWFP, Pakistan during 2008. Information was collected through questionnaire and interviews during field trips. A total of 117 NTFPs species have been recorded which are being used locally for various purposes such as fuel wood, fodder, medicinal plants, vegetables, mushroom, agricultural tools making, furniture, thatching, shade, fencing/ poles, ornamental purpose and animal products. The majority of plants are multi-functional like Pinus wallichiana provides timber, firewood, torch wood, the leaves/small branches are used as thatch for roofing, split logs are used for fencing and the decomposed needles are collected as humus for agricultural fields. These products were widely used by the indigenous community supporting their livelihood. The study proposes protection and sustainable management of these valuable resources for rural livelihoods, which might be useful for developing regional strategies of sustainable management of forest resources.  相似文献   

16.
非木材林产品的民族植物学研究进展   总被引:3,自引:0,他引:3  
非木材林产品(NTFPs)是指从森林植被中采集的药材、食物(如野菜、野果等)、树脂树胶、纤维或其他非木材类产品,它们不仅为当地群众提供了食物、药材等日常生活必需品,而且也是许多地区原住民的重要经济收入来源。在收集整理相关国内外研究资料的基础上,从非木材林产品的集市民族植物学、非木材林产品的经济价值和对原住民经济收入的贡献、影响非木材林产品采集和利用的因素、非木材林产品采集对当地生物多样性的影响、原住民对非木材林产品的传统管理与保护等方面对近年来有关非木材林产品的民族植物学研究进展进行了综合评述,并对非木材林产品的民族植物学重点研究内容和方向提出了一些建议。  相似文献   

17.
建立近自然度评价体系对于修复森林生态功能、保障森林可持续发展有着重要的意义,然而近自然度尚未有统一的评价体系。祁连山地区的森林系统承担着我国西部重要的水源涵养功能,对其现存的人工林客观地开展基于水源涵养能力的近自然评价是亟需解决的问题。以祁连山东部金禅沟、塔尔沟小流域40个不同林分起源的云杉纯林、白桦纯林、云杉白桦混交林为对比研究样地,对涉及近自然度和水源涵养能力的指标进行敏感性分析,筛选出中高敏感度指标,通过欧氏距离法结合熵权法定量评价人工林近自然度,通过模糊物元法定量评价森林水源涵养能力,然后采用6种方法对近自然度和水源涵养得分分布进行拟合(R2>0.4),并利用K-means法建立了4个近自然度评价等级。研究表明祁连山东部地区大部分人工林近自然度评级处于半天然林阶段,通过改造纯林为针阔混交林可以同时提高其近自然度与水源涵养能力。研究旨在构建基于水源涵养能力的近自然度评价体系,为森林生态服务功能修复提供理论支持。  相似文献   

18.
Forestry management worldwide has become increasingly effective at obtaining high timber yields from productive forests. In New Zealand, a focus on improving an increasingly successful and largely Pinus radiata plantation forestry model over the last 150 years has resulted in some of the most productive timber forests in the temperate zone. In contrast to this success, the full range of forested landscapes across New Zealand, including native forests, are impacted by an array of pressures from introduced pests, diseases, and a changing climate, presenting a collective risk of losses in biological, social and economic value. As the national government policies incentivise reforestation and afforestation, the social acceptability of some forms of newly planted forests is also being challenged. Here, we review relevant literature in the area of integrated forest landscape management to optimise forests as nature-based solutions, presenting ‘transitional forestry’ as a model design and management paradigm appropriate to a range of forest types, where forest purpose is placed at the heart of decision making. We use New Zealand as a case study region, describing how this purpose-led transitional forestry model can benefit a cross section of forest types, from industrialised forest plantations to dedicated conservation forests and a range of multiple-purpose forests in between. Transitional forestry is an ongoing multi-decade process of change from current ‘business-as-usual’ forest management to future systems of forest management, embedded across a continuum of forest types. This holistic framework incorporates elements to enhance efficiencies of timber production, improve overall forest landscape resilience, and reduce some potential negative environmental impacts of commercial plantation forestry, while allowing the ecosystem functioning of commercial and non-commercial forests to be maximised, with increased public and biodiversity conservation value. Implementation of transitional forestry addresses tensions that arise between meeting climate mitigation targets and improving biodiversity criteria through afforestation, alongside increasing demand for forest biomass feedstocks to meet the demands of near-term bioenergy and bioeconomy goals. As ambitious government international targets are set for reforestation and afforestation using both native and exotic species, there is an increasing opportunity to make such transitions via integrated thinking that optimises forest values across a continuum of forest types, while embracing the diversity of ways in which such targets can be reached.  相似文献   

19.
我国正处在集体林和国有林林权制度改革的关键时期,亟需理论支持和实践经验,但公、私有制森林管理方式及其生态影响研究缺乏. 欧洲和北美多种所有制森林管理具有较长历史,对所有制管理的内容、方式及其对森林木材产量、生物多样性、景观特性等的影响都有较深入的研究,总结这些研究成果,作为我国林权改革的借鉴尤为必要而迫切.本文综述了以欧洲和北美为代表的国家和地区公有制、私有制(产业化私有制和非产业化私有制)森林管理的目的、方式和生态影响,林权流转和分散,以及在各种所有制间采取的联合保护政策,最后提出了研究展望.  相似文献   

20.
Yang J  Luan XF 《应用生态学报》2011,22(3):800-809
非木材森林产品指来自森林的非木材植物产品,如果实、种子、枝叶、树皮、树胶等,在维持当地居民生活以及森林生物多样性保护中扮演着重要角色.非木材森林产品利用对植物个体、种群、群落和生态系统均会产生影响,这不仅取决于植物的利用部位、生物学或生态学特征,而且与资源的利用方式密切相关.本文从植物生物学和生态学角度综述了非木材森林产品利用影响的研究进展,讨论了研究中存在的问题和今后的研究方向.  相似文献   

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