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1.
This paper examines the trade-offs between woodland management for timber and public good outputs in English woodlands. Recent evidence suggests that some public good values may be declining as a result of a lack of woodland management. Such under-management has been attributed to the decline in timber values and reduction in the productivity of woodlands and forests for timber products. It is argued that assessing the management needs of woodlands in order to enhance public good outputs presents a complex challenge and often depends on a variety of factors, including location, type of woodland, age, condition, substitutability and ownership motivation. However, in most instances a moderate level of management (whether for timber or otherwise) is likely to be beneficial for public good outputs.
Julie UrquhartEmail:
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2.
O'Brien  Elizabeth 《Forestry》2006,79(5):535-551
Urban woodlands and green spaces provide a range of benefitsto people in densely populated areas: as places to use, viewand enjoy. There is increasing interest in green spaces andtheir impacts on people's quality of life. The work describedin this paper involved a partnership between Peabody Trust,a social housing association; the Forestry Commission and Treesfor Cities, an environmental charity. The aim of the projectwas to involve residents in the use and enjoyment of their localwoodland. The research gained an understanding of how the residentsof two housing estates in South London view and experience theirlocal woodland, called Peabody Hill Wood. Three focus groupsand a questionnaire were undertaken with residents. Observationswere also made at a community activity day and walk throughthe wood with local residents. From the analysis of the data,there was a complex mix of attitudes towards Peabody Hill Woodthat related to not only the management of the wood but alsothe management of the buildings by Peabody Trust. This researchhighlights, as a number of other studies have, that woodlandsnear to where people live are valuable spaces and play a significantrole by providing opportunity for contact with nature. Key implicationsof the research suggest that housing associations can have animportant role to play in green space management. Partnershipworking with the environmental sector can help bring about muchneeded improvements to the environment. Working with communitiesand sustaining long-term commitment are also advocated.  相似文献   

3.
The main aim of this project was to explore whether the pine trees in Glen Affric (GAF), one of the more extensive pine woodlands in the northern Scottish Highlands, are, on average, reaching a senescent stage which could ultimately be detrimental to the sustainability of the pine woodland in this region under present management conditions. This aim was realized by (1) comparing the mean stand age of the GAF trees to other pine woodlands around Scotland, (2) exploring whether there was a significant pre-death trend in ring-width series from naturally dead trees and (3) assessing whether a notable change in response of tree growth to climate was noted as a function of age which could indicate that trees were entering a state of senescence.  相似文献   

4.
The growing incidence of new tree pest and disease epidemics, many of them with the potential to radically reshape our native woodlands and forests, is closely linked to a significant upsurge in global trade and transportation in recent decades. At the same time, interventions designed to actually manage any pest and disease outbreaks that occur can reshape forest landscapes in a variety of ways. In this review-based paper we argue that disease-driven interactions between biology, public policy and human agency along pathways of introduction and at outbreak sites will become increasingly common in the Anthropocene, where the latter is understood as an era in which human influence over non-human nature is ever more pervasive. We discuss the nature of these interactions in terms of the increased risk of disease introduction via various trade pathways and through the subsequent policy and behavioural responses to two disease outbreaks made by policymakers and stakeholders in the UK (Phytophthora ramorum and ash dieback (Hymenoscyphus fraxineus)). Human influence is evident both in terms of the underlying risk drivers and in the subsequent course and management of these and other outbreaks.  相似文献   

5.
《Southern Forests》2013,75(4):209-219
Volume of trees is an important parameter in forest management, but only volume models with limited geographical and tree size coverage have previously been developed for Tanzanian miombo woodlands. This study developed models for estimating total, merchantable stem and branches volume applicable for the entire miombo woodlands of Tanzania. We used data from 158 destructively sampled trees, including 55 tree species collected from wide geographical and biophysical ranges. We developed general and site-specific models with diameter at breast height only as the independent variable, together with models with both diameter at breast height and tree height. Leave-one-out cross-validation was used to evaluate the models. The total tree volume models that included diameter at breast height and tree height had appropriate predictive capabilities with relative root mean square errors (RMSEr) ranging from 30.5% to 47.6%. The RMSEr for total tree volume models with diameter at breast height only ranged from 39.9% to 48.0%. The site-specific models had slightly lower RMSEr values relative to the general models. The relative mean prediction error of the general total tree volume model with diameter at breast height and tree height was lower (0.6%) than those of the previously developed models (?30.7% to 31.2%). Based on the evaluations, we recommend the general total tree models to be applied over a wide range of geographical and biophysical conditions in Tanzania.  相似文献   

6.
We present a genetic profile of pedunculate oak (Quercus robur L.) in three woodlands of the Helsinki region. We genotyped all mature trees and samples of seedlings to evaluate patterns of genetic variation and gene flow, and evaluate the long-term stability and natural regeneration of these stands. Although five microsatellite loci showed no significant differences in heterozygosity between generations in most locations, significant (p?per se does not interfere with gene flow over the distances represented here. Based on our findings, a minimal-maintenance program reliant upon natural regeneration of oak in the public parks of Helsinki seems plausible.  相似文献   

7.
作为具有生态价值、经济价值和文化价值等多重价值的生物载体,树木是一种重要的自然资源。自然界中树木的生长、生存始终面临着各种威胁和挑战,其中最大、最不可控的危险因素是风。过高的风载荷可能导致树木整体倾斜、树干弯曲、枝叶折断、折干倒伏以及掘根倒伏等形式的破坏,从而带来严重的生态、经济和文化等方面的损失,而且可能危及人们的生命财产安全。为了保护树木、减少损失,文中对树木风载及其安全性评估的研究进展进行综述。介绍独立树木、林缘树木和林内树木的树木风载荷计算方法;阐述树木折干倒伏和掘根倒伏的安全性检测和评估的研究进展,总结现有评价模型的表现和效果,并概述树木动态响应的影响;提出目前研究中存在的问题,并对未来发展进行展望。  相似文献   

8.
While edge effects on tree water relations are well described for closed forests, they remain under-examined in more open forest types. Similarly, there has been minimal evaluation of the effects of contrasting land uses on the water relations of open forest types in highly fragmented landscapes. We examined edge effects on the water relations and gas exchange of a dominant tree (Eucalyptus arenacea Marginson & Ladiges) in an open forest type (temperate woodland) of south-eastern Australia. Edge effects in replicate woodlands adjoined by cleared agricultural land (pasture edges) were compared with those adjoined by 7- to 9-year-old eucalypt plantation with a 25m fire break (plantation edges). Consistent with studies in closed forest types, edge effects were pronounced at pasture edges where photosynthesis, transpiration and stomatal conductance were greater for edge trees than interior trees (75m into woodlands), and were related to greater light availability and significantly higher branch water potentials at woodland edges than interiors. Nonetheless, gas exchange values were only ~50% greater for edge than interior trees, compared with ~200% previously found in closed forest types. In contrast to woodlands adjoined by pasture, gas exchange in winter was significantly lower for edge than interior trees in woodlands adjoined by plantations, consistent with shading and buffering effects of plantations on edge microclimate. Plantation edge effects were less pronounced in summer, although higher water use efficiency of edge than interior woodland trees indicated possible competition for water between plantation trees and woodland edge trees in the drier months (an effect that might have been more pronounced were there no firebreak between the two land uses). Scaling up of leaf-level water relations to stand transpiration using a Jarvis-type phenomenological model indicated similar differences between edge types. That is, transpiration was greater at pasture than plantation edges in summer months (most likely due to greater water availability at pasture edges), resulting in significantly greater estimates of annual transpiration at pasture than plantation edges (430 vs. 343lm(-2)year(-1), respectively). Our study highlights the need for landscape-level water flux models to account for edge effects on stand transpiration, particularly in highly fragmented landscapes.  相似文献   

9.
Deadwood is an important resource commonly used by inhabitants in arid lands. However, the low wood productivity and the presence of multi-stemmed trees restrict the use. Prosopis flexuosa woodlands are protected and inhabited by pastoralists who have land rights to use natural resources. As in other forests in the world, dead branches are the most commonly used. The factors causing the death of branches these trees are unknown. As P. flexuosa is a highly heliophilous species, branch mortality may depend on the growth habit and orientation of dry branches under the tree crown. With the participation of inhabitants, we assessed the present availability of deadwood in two Prosopis woodlands of different structure (semi-closed and open woodland), and evaluated the formation of deadwood in terms of shape and cardinal location of dry branches under the crown. We developed and compared regression models to estimate the amount of deadwood for erect, semi-erect and decumbent trees, and for the north and south areas under the crown (n = 120 trees). In addition, to determine the period of growth decline and the factors determining branch mortality, we compared annual radial increment between live and dead branches (n = 30 trees; 10 for each tree shape). The total amount of deadwood in adult Prosopis trees is higher in the semi-closed than in the open woodland (8.6 and 4.4 Tn ha−1, respectively). Only tree size determined the amount of deadwood present in each Prosopis tree, since we found no evidence related to the shape of the tree or the position of dry branches in the canopy. Branch decay was a large process of 18-20 years, and branch death appears to be the result of the action of climatic factors (dry period). The results suggest that the use of deadwood by the desert inhabitants is a tool that can potentially be used; however, the use of this resource taking into account the generation rates of deadwood has not been developed in arid lands. These practices at appropriate sites can contribute to a sustainable management of these woodlands, including the removal of deadwood in a model of local management on a site where potential productivity is relatively low.  相似文献   

10.
Experimental forests and ranges are living laboratories that provide opportunities for conducting scientific research and transferring research results to partners and stakeholders. They are invaluable for their long-term data and capacity to foster collaborative, interdisciplinary research. The San Joaquin Experimental Range (SJER) was established to develop appropriate land management practices on foothill rangelands in California. SJER has a long and rich history of avian research. Natural history observations recorded since 1935 demonstrate that oak woodlands are one of the most diverse habitat types in North America. Early avian studies focused on California quail (Callipepla californica) as a game species and led to insights on quail diet and habitat requirements. Starting in the late 1970s, the focus of avian research shifted to methods for detecting changes in wildlife populations over time and response to management practices. This research has led to important recommendations for implementing bird monitoring programs. Using data collected on bird numbers, in conjunction with monitoring reproductive success of all species, recent studies have examined life history strategies, source-sink dynamics, the effects of livestock grazing, and the impacts of an invasive species on native cavity-nesting species. We are currently in the process of examining population trends and predicting the effects of climate change using long-term data. SJER continues to provide unique opportunities for research and educational activities that increase our understanding of the foothill oak woodlands of California.  相似文献   

11.
威信县名木古树保护管理对策   总被引:2,自引:0,他引:2  
介绍威信县名木古树种类、数量、分布等概况以及名木古树所具有的科学研究、革命历史教育及民族文化传承等方面的意义.分析威信县名木古树保护与管理存在着家底不够清楚,管理机构不健全,社会各界保护意识不强,缺乏专项管护经费,管理人员技术素质不高等问题.提出了健全管理机构,提高公众保护意识,多渠道筹集管护经费,强化管理措施,建立和完善监测体系等对策及相关的技术措施.  相似文献   

12.
Tree dwelling bats select cavities in large, old, dying or dead trees. This inevitably brings them into direct conflict with the interests of forest managers, who are trained to fell such trees. Therefore the identification of forest stands providing optimal roosting opportunities for bats is crucial, in order to provide appropriate guidelines for forest management. It is also important to identify the extent to which the roosting ecology of bats changes in response to habitat modification. Bia?owie?a Forest (BF) offers a unique opportunity, in the temperate zone, to observe differences between areas with no direct human intervention and managed areas and in particular to reveal the effect of forest management on the roosting ecology of forest dwelling bat species. We used GIS techniques to evaluate bats’ spatial response to changes in forest structure and to test the hypotheses that the forest dwelling bats Nyctalus noctula and Nyctalus leisleri prefer roost sites within old deciduous or wet woodlands over young and coniferous ones and that roost site preferences reflect the extent to which dead and dying trees are removed. There was a significant difference in the selection of roosting habitat between the managed and pristine areas of the forest. Within the pristine forest, both species displayed a strong preference for roost trees located within old deciduous stands (>100 years), whereas in the managed part of the forest old wet woodland was preferred while all medium and young forest stands were avoided. Our data reveal a high degree of lability in the selection of roosting habitat by bats. It appears that bats are able to respond to changes in their environment by changing their roost site preferences and could therefore occupy habitat previously considered less suitable.  相似文献   

13.
Integrated management of natural resources and the multiple use of trees and forests have prevailed in most European societies since prehistoric times. In the Middle Ages, expanding and intensified agriculture resulted in the separation of trees from agricultural fields. During the last century, with the introduction of sustainable and highly productive forest management, the goal of increased wood production has been achieved in most parts of central, northern, and eastern Europe. Today, agroforestry is not considered to be an important land-use option within the region; however, there are many practices that could rightfully be classified as agroforestry. These include tree/crop systems in which trees provide products and/or environmental benefits, and tree/animal systems in which animals are grazed in forests or open woodlands.The future seems to offer some prospects for agroforestry. Large areas, hitherto used for food production, are either marginally suited to agriculture, or will probably be taken out of production due to agricultural policy considerations. Agroforestry may, at least in part, offer alternatives for the use of such lands. The availability of (surplus) fertile soils, capital, and labor may provide incentives for site-adapted forms of agroforestry, including improved fallow management. The focus of such systems would be on maintenance of biodiversity in the landscape, environmental protection, recreation, and product diversification.There are numerous expectations as to what agroforestry might provide for the land holder and for society as a whole. These expectations should be carefully analyzed and evaluated prior to political decisions on future land use. The promotion of agroforestry requires overall investment; agroforestry does not happen by itself. A set of integrated actions — not isolated efforts — must be implemented if agroforestry is to become a successful land-use option.  相似文献   

14.
The highest deforestation and forest degradation rates in Africa occur in the dry forests and woodlands where pressure for land is increasing, poverty is rampant, livelihood options are few and climate change effects are severe. This paper examines factors that cause land and forest degradation in the Sahel and dry forests and woodlands of eastern and southern Africa and highlights some successful restoration practices, technologies and approaches. In the Sahel, enclosures are used to protect young growing trees while in East Africa enclosures are implemented on degraded land as a mechanism for environmental rehabilitation with a clear biophysical impact. The choice of techniques for rehabilitating specific degraded areas depends first on the priorities and management objectives of stakeholders followed by the costs and benefits associated with available rehabilitation techniques and the economic, social, and environmental values of the land resources in their current and desired future states. In the Sahel, sustainable land management is considered to be an imperative for their sustainable development and the practices include soil and water conservation activities and structures. In all regions, natural forest rehabilitation has used both natural and assisted regeneration to promote the growth of especially indigenous species through coppice regrowth and root suckers rather than seeds. Assisted regeneration was especially prevalent in the Sahel where indigenous tree species have been identified to dominate the degraded sites during early stages of secondary forest succession. The success of any rehabilitation activities depends on community-based natural resources management. In addition, the forest policies and their related policies need to be enabling in order to address issues of concern, including (1) the full participation of communities, (2) clear land and tree tenure and (3) equitable benefit sharing.  相似文献   

15.
16.
生态公益林补偿机制及经营与管护综述   总被引:7,自引:1,他引:7  
实行森林分类经营后,生态公益林建设成为了人们关注的话题。本文就生态公益林生态补偿机制、管理模式与经营技术、公益林管护这三个方面,对国内研究现状做了系统概述。  相似文献   

17.
Private Ownership and Public Good Provision in English Woodlands   总被引:1,自引:1,他引:0  
There is increasing emphasis on multipurpose forestry within UK national and regional forest strategies, with the aim of co-delivering the social, environmental and economic benefits of woodlands. Private woodland ownership is also changing, with an increase in owners without a farming or forestry background. However, there is little substantive evidence relating to the motivations of private woodland owners and, in particular, their ability and willingness to deliver public goods. A qualitative study is adopted, using semi-structured interviews in three areas in England, to address this theoretical gap. Exploratory findings indicate that private woodland owners have a diverse range of objectives, motivations and management regimes which influence the potential for public good delivery. It is shown that some private woodland owners, such as those less motivated by economic return, may be better placed than others to deliver certain public goods; that conflicts can arise between the provision of recreation and nature conservation, especially in smaller woodlands; and that many private woodland owners are sceptical about becoming involved in grant schemes which may help foster public good provision in the private sector.  相似文献   

18.
江苏虞山国家森林公园的森林覆盖率达96%以上.根据样地调查研究,将虞山国家森林公园约占山地面积为74.8%的天然林依群落优势种划分14类群系,为7类植被型.虞山天然林以马尾松林和马尾松、阔叶树混交林为主,山麓有落叶阔叶林和小面积的常绿、落叶阔叶林.论述虞山天然植被的组成、结构、演替和多样性指数,分析虞山天然林顺向演替的稳定性群落.结果表明:依立地环境可分3种不同类型.从演替规律来研究分析虞山植被,从而提出保护和可持续发展该森林公园植被的建议,并从旅游观光角度提出虞山部分森林类型改造的原则和方法.  相似文献   

19.
The modernization and informatization management of ancient and famous trees’ management is an important standard with which the municipal public resource management level of a region or city can be measured.Design and development of ancient and famous trees’three-dimensional management information system was realized based on virtual plant by using integrated techniques of virtual plants and Geographic Information System.The system architecture design was developed on the basis of functional requirements,and the practical system was achieved in Visual Studio 2008 development tools and OpenGL graphics standards.The system has function of ancient trees archives management,three-dimensional reconstruction of the trees surrounding environment,individual tree information inquiry in three-dimensional scene,etc.Application and dissemination of this system will greatly promote the management and protection of ancient and famous trees standardization,informalization and visualization  相似文献   

20.
The United States Department of Agriculture (USDA) Forest Service celebrated the 100th anniversary of its network of experimental forests in 2008. For a century, the network of experimental forests have contributed immensely—both in the US and around the world—to the practical understanding of the environment and to the formation of management approaches and policies that affect our use of forests and the natural resources they contain. Experimental forests provide places for long-term science and management studies in major vegetation types across the 789,140 km2 of public land administered by the Forest Service. They also provide an incredible wealth of records and knowledge of environmental change in natural and managed forest ecosystems across the United States. Pringle Falls Experimental Forest (Pringle Falls), southwest of Bend, Oregon, is the oldest experimental forest in the Pacific Northwest and is the site of some of the earliest forest management and silviculture research in this region. Research at this site began in 1914, and it was formally established as part of the national network of experimental forests in 1931 as a center for silviculture, forest management, and insect and disease research in ponderosa pine forests east of the Oregon Cascade Range. As part of the celebration of the Centennial Anniversary of the network of experimental forests, it is timely to examine a few of the ecological lessons that have resulted from long-term studies at Pringle Falls. Two different yet interconnected themes are traced: (1) management of existing old-growth ponderosa pine; and (2) management of young or immature ponderosa pine. Examples of ecological lessons, drawn from long-term studies established or followed by James W. Barrett, Matt D. Busse, Patrick H. Cochran, Walter G. Dahms, F. Paul Keen, Ernest L. Kolbe, Edwin L. Mowat, William W. Oliver, Ram Oren, Chester T. Youngberg, and Jianwei Zhang illustrate how work at Pringle Falls has both pursued and influenced societal demands for forest management strategies, and how this trajectory has cycled back to the themes under which the experimental forest was first established. Finally, these two themes are integrated as drivers for new landscape-scale long-term research at Pringle Falls, designed to evaluate the effects of thinning and fuel reduction treatments on multiple, interacting forest stresses of fire, insects, wind, and climate change.  相似文献   

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