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1.
Buffer zones around reserves are often suggested, but have rarely been evaluated. We examined their design for small forest reserves (5–225 ha), where buffer zones (200 m wide) would protect the reserves and reduce negative edge effects. The potential buffer zones could be partly protected, but remain as private land. Alternatively, the state may buy land outside reserves (to be included in reserves). To consider opinions of forest owners, we interviewed 33 private forest owners in potential buffer zones of reserves. The respondents were weakly positive to conservation, but disliked a state reserve on their land, or a buffer zone where 50% of the forest would be protected without compensation; however, with compensation the majority of them were neutral or positive to such a buffer zone. In a choice between buffer zone or reserve bought by the state, the great majority of the respondents chose the buffer zone (compensation paid, land still private). We found no relationships between opinions of respondents and conservation values of their forests (densities of old and dead trees), but older owners had forests of higher value. The forest in the potential buffer zones had higher conservation value than other non-protected forests in southern Sweden. Thus, buffer zones may be valuable, and we suggest they are created in cooperation with local residents where this is possible.  相似文献   

2.
Southern Africa's subtropical forest biome, though small and highly fragmented, supports much of the region's biodiversity. With limited resources available for conservation and the exploitative use of forest escalating, identifying a network of priority forest reserves is important. We examine the distribution of forest birds, butterflies and mammals in KwaZulu-Natal, South Africa. Using an iterative algorithm we explore the efficiency of existing protected areas, species richness and rarity hotspots, prime forest sites (selected by forest area) and complementary networks as alternative approaches to priority reserve selection, as well as the potential use of indicator taxa. Existing protected areas represent 98% of species but are relatively inefficient in terms of area. Alternative selection criteria represent a high proportion of species (86–92%) and provide efficient bases for developing fully representative reserve networks. All species are represented within a network of 22 complementary quarter degree cells. This network includes several larger forests and existing protected areas and is recommended for priority conservation. Complementary networks identified separately for birds, butterflies and mammals overlap little, but each represents a high proportion of the remaining taxa, supporting their potential as representative 'indicator' taxa. The evolutionary history of the three main forest types in KwaZulu-Natal explains observed spatial patterns of alternative reserve networks. Priority areas are concentrated in scarp and coastal forest belts, regions of comparatively recent evolutionary activity with high species richness. Afromontane forest is older and less diverse, but its inclusion in any reserve network is necessary for the full representation of forest diversity.  相似文献   

3.
Temperate forests of southern South America are globally important because of their high level of endemism. I argue here that within southern South America, rainforests of the Chilean Coastal Range should be the primary target for new conservation efforts. Historically, most protected areas in southern South America have been designated to preserve forests above 600 m, mainly in the Andes. However, Coastal Range forests have higher species richness and are under greater threat than Andean forests at similar latitudes. Coastal forests are characterized by the presence of numerous narrow-range endemics, among them two monotypic plant families. The higher frequency of endemic species in Coastal Range forests is attributed to its more stable biogeographic history compared to the Andes, particularly during the glacial events of the Quaternary. Due to the extent of human impact, the remaining fragments of coastal forests are quite distant from one another, and are disconnected from the larger protected areas of Andean forests. Only 439000 ha of Valdivian coastal forest still remain, including some remnants of primary forest. New private or public reserves should be created to protect the last remnants of continuous forest remaining on the Coastal Range of the Valdivian region (40–42° S). A different conservation strategy should be applied north of 40° S, where protected areas are too small and fragments are too scattered to maintain viable populations of most vertebrates. In this latter area, I recommend expanding existing reserves, restoring native forests, and interconnecting remnant forests through a corridor network.  相似文献   

4.
Evaluating the effectiveness of existing nature reserve systems for the conservation of tropical forests is an urgent task to save the remaining biodiversity. Here, we tested the effectiveness of the reserve system on Hainan Island by conducting a three-way comparison of changes in forest area in locations within the reserves, adjacent to the reserves, and far outside of the reserves. We used a general linear model to control for the effects of covariates (historical forest area, elevation, slope, and distance to nearest roads), which may also be correlated with the changes in forest area, to better explain the effectiveness of the reserve system. From 2000 to 2010, the forest area inside Hainan’s nature reserve system showed an increase while adjacent unprotected areas and the wider, unprotected landscape both experienced deforestation. However, the simple inside-outside comparisons may overestimate the protective effect of the reserve system. Most nature reserves (>60%) showed increasing fragmentation. And the risk of rapid deforestation remained high at low elevations, where remaining forests tend to be easily logged and converted to commercial plantations. Future conservation efforts should pay more attention to those sites with less challenging environmental conditions.  相似文献   

5.
云南西双版纳自然保护区建设的展望   总被引:1,自引:0,他引:1  
王献溥  张建侯   《广西植物》1987,(3):245-249
<正> 西双版纳是我国仅有的几个热带区域之一,天然热带森林覆盖面积较大,野生生物种类丰富。这是西双版纳的一个资源优势,如何在加强保护的基础上合理开发利用这些资源,不仅是本地经济建设的一个重要部分,而且是全国甚至全世界人们所关心的事情。因为,全球热带森林由于过分的开发,正以惊人的速度消失,对于热带陆地区域面积不大的中国来说,西双版纳热带森林的重要意义是可想而知的。1979年以前各个自然保护区遭到严重的破坏已成过去,不必再提,关键在于对1979年以后总结了过去的经验教训重新划  相似文献   

6.
To assess whether imperiled species are covered by existing protections in the biologically-rich state of Nevada, U.S.A., we compared the distribution of reserves with known imperiled species occurrences. For species poorly represented in reserves, we determined whether they were receiving alternate protection under the U.S. Endangered Species Act or voluntary conservation plans. A majority (212, 55%) of Nevada’s 384 imperiled species had fewer than 25% of occurrences in reserves and most (282, 68%) had fewer than 50% of occurrences in reserves. Of imperiled species with less than 25% or fewer than two occurrences in reserves, only 9% are currently receiving alternate protection from the Endangered Species Act or voluntary plans. These results suggest that providing protection for imperiled species in Nevada will require both an expansion of the existing reserve system, which currently covers 14% of the state, and protection of more species under the Endangered Species Act or other programs. By dividing Nevada into equal-sized hexagons and scoring each of these hexagons based on a rarity-weighted richness index of imperiled species occurrences, we identified 19 imperiled species hot spots in Nevada. No imperiled species occurrences were protected in seven (37%) and less than half were protected in 11 (58%) of these hot spots. Protecting these areas could provide important additional protection for imperiled species in Nevada. Evaluations of protective measures for biological diversity should include the full suite of protections, including both reserves and laws and regulations.  相似文献   

7.
Mature forests have structural habitat features that can take hundreds of years to develop, and large reserves alone are unlikely to ensure conservation of the species that rely on these features. This paper outlines a proposed new approach to managing mature forest features, the ‘mature habitat management approach’, in areas outside of reserves. The objective was to maintain a network of current and future mature forest habitat distributed across the landscape. The approach is designed to complement the existing reserve network and management actions and is tenure‐blind. Spatial information on the availability of mature forest habitat at the local (1‐km radius) and landscape (5‐km radius) scales is used for decisions on retention within a 1‐km radius of a harvest area, to reach the minimum target of 20% and 30% retention of mature forest at the local and landscape spatial scales, respectively. We believe this approach could contribute to meeting the conservation needs of many species that require mature forest features for refuge and breeding in Tasmania and elsewhere.  相似文献   

8.
Minimum complementary sets of sites that represent each species at least once have been argued to provide a nominal core reserve network and the starting point for regional conservation programs. However, this approach may be inadequate if there is a tendency to represent several species at marginal areas within their ranges, which may occur if high efficiency results from preferential selection of sites in areas of ecological transition. Here we use data on the distributions of birds in South Africa and Lesotho to explore this idea. We found that for five measures that are expected to reflect the location of areas of ecological transition, complementary sets tend to select higher values of these measures than expected by chance. We recommend that methods for the identification of priority areas for conservation that incorporate viability concerns be preferred to minimum representation sets, even if this results in more costly reserve networks.  相似文献   

9.
We investigated the major patterns of plant rarity in sub-Saharan Africa, and looked for the most significant gaps in the reserve network of the region in terms of representing the distribution of threatened and geographically rare plants. Comparisons of the species ranges captured by the network of reserves were made against the proportion of species captured by randomly generated sets of areas and against a theoretical near minimum set of areas that represent all species once. At this scale of analysis, the network of large IUCN-coded reserves (the official ‘protected areas’) performs poorly against random and systematic selection procedures. Significant gaps in the IUCN-coded protected areas are in coastal Gabon/Cameroon, in the various tropical montane forest areas (Cameroon Highlands, Eastern Arc Mountains, Ethiopian Mountains), in lowland coastal eastern Africa, and in the South African Cape. Some of these gaps, for example in the Eastern Arc and eastern African coastal regions, are covered on the ground by a network of Forest Reserves under the management of national Forestry Authorities. The networks of Forest Reserves in Ghana, Nigeria, Cameroon, Uganda, Kenya, Zimbabwe, Zambia and Sierra Leone also fill reservation gaps for rare African plants in these countries. Upgrading the conservation status of some key Forest Reserves, which has been gradually happening for some decades, is proposed as an efficient way to enhance the protected area network of the Afrotropical region for the conservation of rare African plant species.  相似文献   

10.
Sacred forest groves in Ghana are centuries old protected areas that were once part of continuous forest cover but now mostly exist as relict forest patches embedded in an agropastoral landscape. We conducted a year-long survey of the fruit-feeding butterfly fauna of four sacred groves and two forest reserves in the moist semi-deciduous forest zone of Ghana to characterize resident species diversity and complementarity among communities. Joint analysis of frugivorous butterfly diversity at these six forest fragments, which ranged in size from 6 to 5000 ha, was used to evaluate the conservation potential of these ancient indigenous reserves. A total of 6836 individuals were trapped across all sites, representing 79 species and five subfamilies. Community diversity was characterized in terms of, (a) number of species accumulated versus sampling effort, (b) rarefied species richness, (c) nonparametric richness estimates, (d) species evenness, (e) Simpson’s Index of Diversity, and (f) complementarity of communities. Diversity of the fruit-feeding butterfly communities, quantified in terms of both species evenness and rarefied species richness, was higher at the larger forest reserves than at the small sacred forest groves. Additionally, although all sites had species trapped only at that site, the 5000-ha forest reserve harbored a resident community that was clearly distinctive from and more diverse than the other communities including the other forest reserve. Hence, our findings add to the burgeoning body of data that indicates large reserves are the foundation of successful conservation programs. Nonetheless, we found these small forest patches contribute to biodiversity conservation in at least three ways and these are identified and discussed. We also identify a number of species that appear more or less vulnerable to dynamics of forest fragmentation based on changes in their relative abundance across sites and we interpret these data in the context of potential indicator species and theoretical predictions of at-risk species.  相似文献   

11.
Montane tropical cloud forests, with their complex topography, biodiversity, high numbers of endemic species, and rapid rates of clearing, are a top global conservation priority. However, species distributions at local and landscape scales in cloud forests are still poorly understood, in part because few regions have been surveyed. Empirical work has focused on species distributions along elevation gradients, but spatial variation among forests at the same elevation is less commonly investigated. In this study, the first to compare tree communities across multiple Andean cloud forests at similar elevations, we surveyed trees in five ridge‐top forest reserves at the upper end of the ‘mid‐elevation diversity bulge’ (1900–2250 masl) in the Intag Valley, a heavily deforested region in the Ecuadorian Andes. We found that tree communities were distinct in reserves located as close as 10 to 35 km apart, and that spatially closer forests were not more similar to one another. Although larger (1500 to 6880 ha), more intact forests contained significantly more tree species (108–120 species/0.1 ha) than smaller (30 to 780 ha) ones (56–87 species/0.1 ha), each reserve had unique combinations of more common species, and contained high proportions of species not found in the others. Results thus suggest that protecting multiple cloud forest patches within this narrow elevational band is essential to conserve landscape‐level tree diversity, and that even small forest reserves contribute significantly to biodiversity conservation. These findings can be applied to create management plans to conserve and restore cloud forests in the Andes and tropical montane cloud forests elsewhere.  相似文献   

12.
The diversity of the Iberian vascular flora has been investigated using WORLDMAP versions 3.08 and 3.18. Two data sets scoring plant distributions as presences within the Iberian Peninsula were compiled; one for 2133 species at 50 × 50 km grid and the other for 801 species at 10 × 10 km map grids. Patterns of biodiversity were determined using the diversity measures of species richness, range-size rarity and character richness diversity. Using the diversity measures, combined with an area selection method, maps of priority areas were calculated using iterative procedures. Near minimum sets (NMSs) for both scales were calculated. Comparison of the NMS for the 10 × 10 km grid with the near minimum set for existing reserves (NMSER) showed that at least 2% more of the land surface would be required above and beyond the existing protected area network, currently comprising 6% of the area, to ensure representation of all species at least once as listed within the present data-base. It is demonstrated that reserve systems selected on a variety of different criteria are suboptimal when compared to particular groups of target organisms with a definite goal of representation for conservation. Calculating efficiency of existing reserve systems and accounting for all taxa identifies precisely the extra required areas for the protected area system to satisfy particular goals of representation.  相似文献   

13.
With only five protected areas dedicated to the conservation of biodiversity (two national parks, one strict nature reserve and two faunal reserves), Guinea has one of the smallest protected area networks in West Africa. As a result, two of the five ecoregions of the country and six of the 14 globally threatened large and medium-sized mammals occurring in Guinea are not found in the national protected area network. To identify areas with high biodiversity that could be included in the national protected area network, we used the Key Biodiversity Areas (KBA) methodology. We devised a scoring system to rank the identified KBAs according to their relative conservation significance. We identified a total of 16 KBAs throughout the country. Their proclamation as protected areas would result in the protection of all ecoregions and all but one of Guinea’s globally threatened large and medium-sized mammals. Twelve of the 16 KBAs have the legal status of classified forest, a status that should facilitate the change into formal biodiversity protected areas (IUCN category I–IV). Our analysis indicates that even if only the two areas with the highest conservation significance score, the Ziama and Diécké forests, become formal protected areas, this would provide protection to both the western Guinean lowland forests, one of the most threatened ecoregions in Africa, and to 11 of the 14 threatened large and medium-sized mammals occurring in Guinea.  相似文献   

14.
Increasingly, biogeographical knowledge and analysis are playing a fundamental role in assessing the representativeness of biodiversity in protected areas, and in identifying critical areas for conservation. With almost 20% of the country assigned to protected areas, Chile is well above the conservation target (i.e. 10–12%) proposed by many international conservation organizations. Moreover, the Chilean government has recently proposed new conservation priority sites to improve the current protected area network. Here, we used all 653 terrestrial vertebrate species present in continental Chile to assess the performance of the existing and proposed reserve networks. Using geographical information systems, we overlaid maps of species distribution, current protected areas, and proposed conservation priority sites to assess how well each species is represented within these networks. Additionally, we performed a systematic reserve selection procedure to identify alternative conservation areas for expanding the current reserve system. Our results show that over 13% of the species are not covered by any existing protected area, and that 73% of Chilean vertebrate species can be considered partial gaps, with only a small fraction of their geographical ranges currently under protection. The coverage is also deficient for endemic (species confined to Chile) and threatened species. While the proposed priority sites do increase coverage, we found that there are still several gaps and these are not the most efficient choices. Both the gap analysis and the reserve selection analysis identified important areas to be added to the existing reserve system, mostly in northern and central Chile. This study underscores the need for a systematic conservation planning approach to redefine the conservation priority sites in order to maximize the representation of species, particularly endemic and threatened species.  相似文献   

15.
Tropical forests contain much of the world's biodiversity, yet their rate of decline is increasing. The strategy most frequently used to protect this biodiversity is to make parks and reserves. While there is a great deal of research on the effectiveness of parks for protecting biodiversity, there is little research on how well extractive reserves conserve biodiversity. Here, we evaluate the effectiveness of four forest reserves in western Uganda at maintaining populations of primates and compare census data from the reserves to data from the neighbouring well‐protected Kibale National Park. The relative abundance of the five most common primates in the park was approximately four times that of the forest reserves. In the forest reserves, evidence of new human encroachment was seen every 500 m, while in the park it was seen every 100,000 m. Two recommendations emerge from our research: (i) for forest reserves, such as those studied here, to have conservation value for primates, extraction must be reduced and (ii) until the long‐term viability of the populations in forest reserves can be ascertained, they should not be considered in estimates of the sizes of endangered species protected ranges.  相似文献   

16.
It is crucial for biodiversity conservation that protected areas are large and effective enough to support viable populations of their original species. We used a point count distance sampling method to estimate population sizes of a range of bird species in three Atlantic forest protected areas of size 5600, 22,500, and 46,050 ha. Population sizes were generally related to reserve area, although in the mid-sized reserve, there were many rare species reflecting a high degree of habitat heterogeneity. The proportions of forest species having estimated populations >500 ranged from 55% of 210 species in the largest reserve to just 25% of 140 species in the smallest reserve. All forest species in the largest reserves had expected populations >100, but in the small reserve, 28% (38 species) had populations <100 individuals. Atlantic forest endemics were no more or less likely to have small populations than widespread species. There are 79 reserves (>1000 ha) in the Atlantic forest lowlands. However, all but three reserves in the north of the region (Espírito Santo and states north) are smaller than 10,000 ha, and we predict serious levels of local extinction from these reserves. Habitat heterogeneity within reserves may promote species richness within them, but it may also be important in determining species loss over time by suppressing populations of individual species. We suggest that most reserves in the region are so small that homogeneity in the habitat/altitude within them is beneficial for maintenance of their (comparatively small) original species compliment. A lack of protection in the north, continued detrimental human activity inside reserves, and our poor knowledge of how well the reserve system protects individual taxa, are crucial considerations in biodiversity management in the region.  相似文献   

17.
Aim To examine biogeographical affiliations, habitat‐associated heterogeneity and endemism of avian assemblages in sand forest patches and the savanna‐like mixed woodland matrix. Location Two reserves in the Maputaland Centre of Endemism (MC) on the southern Mozambique Coastal Plain of northern KwaZulu‐Natal, South Africa. Methods Replicated surveys were undertaken in each of the two habitat types in each reserve, providing species abundance data over a full year. Vegetation structure at each of the survey sites was also quantified. Differences between the bird assemblages and the extent to which vegetation structure explained these differences were assessed using multi‐variate techniques. Biogeographical comparisons were based on species presence/absence data and clustering techniques. Results Bird assemblages differed significantly between habitats both within a given reserve and between reserves, and also between reserves for a given habitat. Differences in vegetation structure contributed substantially to differences between the avian assemblages. Of the four species endemic to the MC, three (Neergaard’s sunbird, Rudd’s apalis, and Woodward’s batis) were consistently present in sand forest. The fourth (pink‐throated twinspot) preferred mixed woodland. None of these endemic species was classed as rare. In the biogeographical analysis, both the sand forest and the mixed woodland bird assemblages were most similar to bird assemblages found in the forest biome or the Afromontane forest biome, depending on the biome classification used. Main conclusions The close affinities of sand forest and mixed woodland assemblages to those of the forest biome are most likely due to similarities in vegetation structure of these forests. Bird assemblages differ between the sand forest and mixed woodland habitats both within a given reserve and between reserves, and also between reserves for a given habitat. These differences extend to species endemic to the MC. Thus, conservation of sand forest habitat in a variety of areas is necessary to ensure the long‐term persistence of the biota.  相似文献   

18.
We assessed the ecological structure and function of mountain ridges connected to a reserve area, Gwangneung Royal Tomb Forest (GRTF), in central Korea. This site has been strictly preserved since the 15th century. Our objectives were to 1 ) investigate the interactions between and the influence of a protected old-growth forest on its surrounding forests, and 2) suggest management strategies for forests outside that reserve area. Three ridges were surveyed and divided into two categories — A and B ridges covered with secondary forests connected to GRTF, and the C ridge, covered with primary forests and plantations within GRTF (from core zone to managed zone). The ridge forests had a characteristic lobe shape. We found no significant decline in species richness (peninsular effect) with distance from GRTF for any tree-layer or herbaceous-layer species on Ridges A or B. However, when only the species that appeared in primary forests on the C ridge were considered, the richness of tree- and herbaceous-layer species was significantly decreased there. This meant that the neighboring forests of GRTF could serve as a buffer zone. Differences were obvious between the two categorized forests in their species composition, species richness, basal area, and regeneration patterns. DCA ordination of quadrats on Ridges A and B showed that Axis 1 was significantly correlated with distance from GRTF, indicating that this protected area affects regeneration within neighboring forests. Thus, reserves are important not only to the conservation of biodiversity, but also to the ecological management of surrounding forests.  相似文献   

19.
Knowledge of the fauna of tropical lowland rainforest is urgently necessary because of the high rate of biodiversity loss and global extinction of species as a result of deforestation. We studied land molluscs species richness and diversity in four heavily degraded secondary forest reserves and one old‐growth forest reserve in Edo State, Nigeria using a combination of direct fixed‐time search and litter‐sieving techniques in twelve plots of 400 m2 each per reserve. A total of 43 species and 2570 individuals were collected from all the reserves. Local species richness ranged from 19 to 39 species while number of specimens from 203 to 971. Molluscan species richness and diversity is significantly higher in the old‐growth forest than in the disturbed forest reserves. Land molluscs family composition was similar in all the forests with respect to the common and wide‐ranging species while rare and narrow‐range species are restricted to the old‐growth forest in Okomu. The carnivorous streptaxids and detritivorous subulinids dominate species richness and abundance respectively in all the sites. Species turnover is moderately high within and between the forest reserves indicating the uniqueness of the faunal composition of each forest and the need for adequate protection.  相似文献   

20.
Timber production forests can support diverse ecological communities, but existing conservation strategies fail to maximize this potential. While methods for limiting logging damage and locating biological reserves have been developed, strategies focused on the sequence and arrangement of harvest units are lacking, particularly for situations in which species-specific knowledge is limited. We present a new landscape-level approach to forest conservation that anticipates local extinctions and focuses on facilitating re-colonization via strategic spatiotemporal harvest plans (which are informed by species occurrence data only). As a proof of concept, we applied our framework to data from four tropical forest sites and found clear benefits of optimized spatiotemporal harvest plans relative to non-optimized harvest plans (random and three pattern-based plans). Our proposed approach, termed the Optimized Floating Refugia strategy, requires minimal species-specific knowledge and can be used to enhance existing conservation efforts (e.g. biological reserve establishment, reduced-impact logging). The approach effectively prioritizes logging-sensitive habitat specialists with restricted ranges and thus provides the largest benefits to the most extinction-prone species. This simple but novel method shows promise as a general strategy to improve biodiversity conservation in species-rich production forest landscapes.  相似文献   

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