首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Forests expanded rapidly in northwestern Vietnam in the 1990s. Forest expansion coincided with a new forest policy that mandated the devolution of forest management authority. A cornerstone of the new policy was the allocation of use rights for forestry land and trees to rural households. This paper examines to what extent the new forest policy contributed to the observed forest expansion. The findings of three village studies suggest that the new forest policy had minor effects on actual property rights, as villagers resisted its implementation. Instead, forests expanded, mainly due to the liberalization of agricultural output markets and availability of new technology. Changes in markets and technology motivated farmers to intensify crop production, reducing agricultural pressure on land. The research findings suggest the potential of market-based instruments and technology policy to facilitate forest regeneration. They also demonstrate the benefits of in-depth village studies for forest policy analysis, as it provides an integrated framework for assessing the relative effects of political, economic and technological changes on forests.  相似文献   

3.
The last decades brought along a tremendous expansion of rubber plantations as well as respective socio-economic transformations. This paper reviews the historical development of rubber cultivation with special reference to intercropping and illustrates the major development steps. The agronomic challenges of intercropping are analyzed and a management classification scheme is suggested. Though the topic of labor always accompanied rubber management, it is nowadays of even higher relevance due to alternative income options, be it due to competing crops such as oil palm, or be it off-farm income opportunities. This development challenges labor intensive permanent intercropping systems. It can thus be concluded that the permanent integration of additional plants needs either to be highly profitable or at least be labor extensive to be adopted on a considerable scale. Given the large area of rubber plantations the latter seems to be more realistic. In this context timber trees might offer promising options if tree selection is properly adapted to site and plantation conditions. Nevertheless, without external interventions, such as land-use planning and implementation, or incentives, the development will be difficult to control.  相似文献   

4.
Gap fellings are used to promote multi-cohort structures and to restore other natural forest structures and processes in protected areas that have been altered by anthropogenic activities. Gaps and felled trees may also provide breeding material for species that in high numbers can cause significant tree mortality, growth reduction and consequent economic losses in surrounding production forests. In this study, the effect of restoration gap fellings on feeding intensity of Tomicus spp. (pine shoot beetles) was evaluated by counting fallen pine shoots at different distances from gaps in a protected area in eastern Finland. Gap fellings had a clear effect on the feeding intensity of the beetles. The average density of fallen shoots m−2 was 17 within a 10-m distance from gaps but decreased rapidly to around 4 at the distance of 50 m and beyond. The distance decay in shoot feeding is described well by the negative exponential models. Our results suggest that gap fellings have only a localized effect on shoot feeding by Tomicus in the forests surrounding the restoration gaps. In practical restoration, a buffer zone of 100–200 m around the gap fellings, as implemented here, is enough to minimize economically significant growth reduction in surrounding production forests. As shown in this study, restoration of natural forest structures and dynamics to protect biodiversity is not necessarily in conflict with forest hygiene objectives in production forests.  相似文献   

5.
This paper explores an emerging discourse at the UNFCCC level - the integrated landscape approach discourse, which brings new understandings of how to approach forests in a climate change nexus. Its proponents argue that forestry, agriculture and other land uses cannot be seen in isolation, but need to be integrated into a single management process. I apply argumentative discourse analysis (Hajer, 1995) to a series of documents, statements, observations and interviews to identify and analyze the power of this discourse in the UNFCCC and in particular on the reducing emissions from deforestation and forest degradation (REDD+) negotiations. The paper highlights the central arguments of its storylines, its main critique and identifies members of its discourse coalition. It also assesses its discursive power, and concludes that although storylines of the integrated landscape approach discourse may be well recognized in the UNFCCC, in particular at side-events (discourse structuration), it has yet to impose its logics and rationales in a profound way (discourse institutionalization).  相似文献   

6.
The economy of the Ukraine is in transition from a communist command-and-control to a capitalist system. In this paper, we describe the current state of its forest resources, the structure of its forestry and wood processing sectors, and the problems facing policy makers. While the forest sector should be, and still has the potential to become, an engine for economic growth, the combination of past exploitation and the slow pace of economic reform are major obstacles to implementing rational forest policies. Given the right economic incentives and appropriate forest policies, it may still be possible for the Ukraine to improve its future timber supply while enjoying environmental benefits from its forests. However, this requires economic and institutional reforms beyond the forest sector.  相似文献   

7.
8.
The importance of different fractions of coarse wood debris (cwd) for species diversity of wood-inhabiting fungi was investigated in near-natural Danish beech stands. Species number per tree increased significantly with increasing tree size, pointing out large trees to be most valuable for fungal diversity if single samples are compared. Rarefaction curves, evaluating the importance of different cwd fractions in a cumulative space, revealed a different and more complex picture. Rarefaction curves based on wood volume showed small trees and branches to host more species per volume unit than larger trees and logs, respectively, while snags were the most species-poor fraction. Surface-based curves showed species density to be rather similar among cwd types, though species density still decreased slightly with tree size. These results are interpreted to reflect a combination of two factors: firstly, small diameter cwd represent a larger surface area per volume and hence more space for fungal sporocarps, than large diameter cwd. This ‘surface area factor’ explains the high degree of similarity of the surface-based rarefaction curves. Secondly, a collection of small diameter cwd involves more separate units than an equal volume of large diameter cwd, and represents thereby more individual cases of fungal infection and, most likely, more variation in environmental conditions. The effect of this ‘number of item factor’ is reflected in the slightly increasing species density per surface area with decreasing tree size. Richness patterns of red-listed and non-red-listed species were found to be strikingly similar across cwd types, and a general preference for large logs among red-listed species was hence absent. An individual look at the most frequent encountered red-listed species revealed substrate preference patterns to occur in three of six species, of which one, the heart-rot agent Ischnoderma resinosum, preferred large logs. Based on these results, it would be obvious to conclude that local fungal species diversity is most efficiently increased in managed forests if small diameter cwd is prioritised for natural decay. However, small diameter wood appear to be unable to support heart-rot agents and other species depending on a long and diverse infection history and thus the integrity of saproxylic communities may be seriously undermined if only small diameter cwd is left for decay. Therefore, we strongly recommend that whole, naturally dead trees, representing the full range of cwd habitats, are prioritised for natural decay in managed forests whenever possible.  相似文献   

9.
This article addresses the German debate on the issue of the common welfare designation of public forests. In the first part, drawing on two case studies, the political discourse on the issue is introduced. Two major competing ‘story lines’ can be made out that are both based on a long tradition of controversially discussed concepts of regulatory forest policy. While they both emphasise that common welfare services in forestry run counter to profit orientation, they fundamentally differ with regard to the consequences for forest policy, e.g., considering the degree of state intervention. Afterwards, an overview on the scientific debate on common welfare in the German context is given, and different concepts of common welfare determination are distinguished. Existing approaches of common welfare determination in German forest policy are related to these concepts and discussed. It is argued that the common welfare designation of the public forest is only insufficiently implemented by the actual governance arrangements. Based on this consideration, eventually, the implementation of a procedural concept of common welfare operationalisation in Germany’s public forests at the local level is proposed. While such a concept will not solve all complex problems related to the determination of common welfare in public forestry, it would notably contribute to a more operational definition of common welfare in public forestry and a more informed public debate on the issue.  相似文献   

10.
Political responses to global deforestation, as a defining characteristic of the so-called Anthropocene, are a key field for scholarship and policy analysis. In the past decade, research has proliferated on global forest governance and the international forest regime (IFR), yet the academic literature on the IFR is just as dispersed and fragmented as the IFR itself. An emerging body of literature now suggests the key role of domestic actors in international forest governance, questioning an implicit top-down logic of global arrangements. In spite of all the resources at its disposal, the IFR is characterised by complexity, fragmentation and ineffectiveness regarding its main objective of reducing global deforestation.Based on an extensive literature review, the authors’ long-standing observations and selected own empirical findings, this review article aims to provide an updated historical account of the IFR and proposes a from-below approach for analysing the IFR from the viewpoint of domestic actors. In this bottom-up perspective the IFR is conceptualised as a set of resources that key domestic actors can pick and choose from according to their interests and in the light of domestic politics.Using illustrative empirical examples from recent research and own observations, the article finds that the IFR is being hollowed-out by (i) the growing policy links between forests and climate change - a process referred to as “climatization”- and (ii) domestic influences. We conclude that our from-below approach is instrumental in further explaining why deforestation has largely continued, despite the emergence of the IFR some three decades ago. Our findings about the importance of domestic actors illustrate that global governance arrangements cannot operate effectively, relative to their ambitious mandate and for tackling policy issues relating to the Anthropocene, unless they are granted adequate resources and support by key domestic actors.  相似文献   

11.
Where natural production capacity permits, modern silvicultural management in Central Europe frequently aims at the development of mixed broadleaved stands, instead of pure European beech (Fagus sylvatica) stands. It is crucial to study the effects of these tree-layer diversity variations on herb-layer vegetation, since herb-layer vegetation contributes significantly to ecosystem functioning in forests. In Hainich National Park (Thuringia, Germany), we conducted observational research in deciduous stands to investigate whether herb-layer diversity was related to canopy-layer diversity, and to ascertain possible causal mechanisms. We found that herb-layer vegetation of deciduous forest stands rich in canopy species appeared to be more diverse than herb-layer vegetation of beech-dominated stands. We surmise that herbaceous understorey diversity was indirectly influenced by canopy tree species through the medium of the altered environmental factors soil pH and litter layer thickness. Apparently, lower beech proportion had a more profound effect than the number of secondary tree species. There were no correlations between herb-layer diversity and light transmissibility of the canopy layer, indicating that the light factor was not crucial for herb-layer diversity. At least for the Hainich research sites, our results indicated that small-scale light and soil heterogeneity is insignificant for herb-layer diversity. We found several herb-layer species whose occurrence was particularly correlated with tree-layer diversity and environmental factors. Remarkably, all species positively correlated with soil pH were important for the phytosociological classification of the research sites. Beech-dominated research sites showed high tree-layer volumes, whereas research sites with high tree-layer diversity tended to feature lower tree-layer volumes. These findings could be the result of differing former silvicultural systems and varying soil clay contents affecting tree species composition. In contrast, herb-layer biomass was positively correlated with tree-layer diversity. Herb-layer productivity might be promoted in more diverse research sites by increased nutrient supply and base saturation. It is also possible that greater beech proportion interfered with herb-layer productivity. However, herb-layer biomass was also positively correlated with herb-layer diversity. Hence, our study hints that positive diversity-functioning relationships might occur in the herb-layer of the deciduous forest under investigation.  相似文献   

12.
Wildfire risk related to hazards on people and assets is expected to increase in the face of climate change, especially in fire-prone environments such as the M...  相似文献   

13.
14.
Ownership is a multidimensional phenomenon that includes legal, social, and emotional aspects. In addition to legal aspects, the social and emotional aspects, “feelings of ownership,” potentially have behavioral effects. Nevertheless, these aspects are often overlooked in the research influencing the forest owners' behavior and thus their forest management decisions. This article examines how private forest owners with inherited forest holdings construct feelings of ownership toward their forests and how these constructions are reflected in their forest management decisions. Forest ownership is addressed through the theory of psychological ownership. On the basis of 15 thematic in-depth interviews, we suggest that a sense of identity and control, as dimensions of psychological ownership, can influence whether forest management decisions are guided by tradition, economic incentives, or responsibility toward property. Based on the results, a forest owner typology (restricted, indifferent, informed, and detached forest owners) was constructed, further enabling us to understand the differences among private forest owners and the roots of their forest management decisions. More generally, the study highlights the important role of emotions in forest management decisions.  相似文献   

15.
Research into deer population dynamics has mostly focused on community or landscape scales in the Republic of Ireland. However, in order to propose national deer management strategies to confront the increasing deer populations in recent years, a larger scale analysis of deer populations is necessary. In this inter-county, national study, generalised linear mixed models were utilised to examine the relationship between the harvest rate (defined as the numbers harvested per 100?ha in this study) data and factors identified in past research as contributing to deer population dynamics on a county basis, where annual county-level deer harvest records were used to reflect deer populations by species. The procedures were repeated for each species and significant factors and their impacts were identified for each county. The results suggested that multiple factors affect deer population dynamics; for instance, increases in forest cover tended to result in increases in deer populations of all species, and the presence of red and sika deer populations in a county had a positive influence on hybrid deer populations. National migration maps for each deer species were produced, as well as predictions of future population trends. The outcome of this study can be used to guide the development of a national deer management strategy and the prioritisation, on a regional basis, of deer control measures.  相似文献   

16.
Roughly 2.8 billion people burn wood for basic energy needs, and traditional wood-fuel represents ~55% of global wood harvest. With increasing anthropogenic disturbance of natural forests, the “stability/fragility” paradigm of forest ecology is gradually being replaced by a “disturbance/recovery” paradigm. In order to understand effects of human-induced disturbances on natural forest ecosystems, and to plan for recovery of disturbed forests, appropriate metrics become necessary. Such metrics will aid in assessment and management of forests for carbon sequestration, biodiversity conservation, ecosystem health, and sustainability of natural resources. Such metrics are especially needed in “wood-fuel hotspots” of the world where over 275 million people live and harvest wood-fuel unsustainably. In this article, I provide metrics of human-induced disturbance in Nepal’s SchimaCastanopsis dominated forests and show relationships of disturbance intensity with forest structure and composition, site productivity potential, natural regeneration, and tree species diversity. Benchmark data were collected from survey of two protected reference forests and compared against three other forests representing a disturbance gradient. The SchimaCastanopsis association is a common dominant forest type in the warm temperate zone of the central Himalayas, and the findings from this study should have wider application.  相似文献   

17.
The elementary method based on Faustmann's analysis and extended by Hartman is used for the design of payment schemes inciting forest owners to manage their assets in a way more conducive to nature conservation. It is not aimed at extending the elementary theory but rather, to elicit its most important empirical implications. It is taken for granted that the conservation benefit of a forest increases linearly with time. Linearity is not only in sufficient agreement with ecological facts but also makes it easy to derive important conditions, in particular the minimal payment inducing owners never to harvest. The theory is applied to a German beech forest model (Fagus sylvatica). It is found that inciting owners to delay cutting cannot be recommended. The instrument should be used for the objective of abandoning cutting altogether which, however, demands that the conservation objective, as expressed in its present value, is granted a very high value by society. In the sequel, various aspects as to the scheme's practicability are discussed, including the need to capitalise annual payments into one single sum, the choice of a discount rate, the allowance for current costs in forestry and the likely approval of payments in the political arena. Although the discussion identifies several obstacles to the practical application of the scheme, there appears to exist no principal reason why a conservation policy based on the Faustmann–Hartman approach should not work in forestry.  相似文献   

18.
Recent studies have highlighted the key role of tree microhabitats in forest habitat complexity and have suggested using them as surrogates for local taxonomic biodiversity. However, few practical guidelines have been published to help foresters in managing microhabitats at the stand scale. This paper provides scientific background information to help to develop such guidelines. We surveyed trees in nine long-unmanaged beech–fir forests to model tree microhabitat occurrence and diversity at the tree level. Data were upscaled to a size range of tree cluster, i.e., at the tree population scale, by aggregating observed values of microhabitat occurrence. Accumulation curves were used to estimate the minimum number of trees required to make all the microhabitat types available. Two managed forests were then studied to quantify management effects on microhabitats. Diameter at breast height (dbh) and tree species, respectively, explained 16 and 10 % of the variations in the number of microhabitat-bearing trees, and 21 and 10 % for the number of microhabitat types. Beech trees and firs with a dbh of less than dbh 50 and 65 cm, respectively, did not ensure the provision of all microhabitat types. At least 20 ha of unmanaged forest were necessary to conserve all the microhabitat types. Current management practices have reduced the number of microhabitat-bearing beeches both by reducing the number of very large trees (dbh > 67.5 cm) and by tree selection within mid-size diameters. For fir, only the logging of very large trees (dbh > 62.5 cm) negatively affected microhabitats. These figures may inspire guidelines for conservation-friendly forestry.  相似文献   

19.
20.
The following attempt at a short essay is based on observations predominantly made in Germany and personal experiences respectively. Its aim is to portray how the author reached ‘the theory’ and how history in general as well as the historiography of forestry in particular approaches theory and its underlying assumptions. As a result, the diverse historical sub-disciplines are endeavoring with varying ‘success’ to employ and develop theoretical approaches (theory turn). However, as there is no consensus on an operational definition of theory to the present day, this dialog focuses on epistemological reflections rather than theoretical models.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号