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Establishing protected areas is one of the most widely used tools for biodiversity conservation, but the effectiveness of
this is disputed. We used satellite-based maps of land cover to compare forest cover and rate of forest loss before and after
28 Mexican protected areas were decreed. Forest cover declined over time, both inside and outside reserves, but the loss was
lowest in designated core areas. No significant difference was found in the mean rate of change in forest cover between external
buffer, decreed areas and areas not yet decreed. There was also no significant difference in forest loss among protected areas
before and after being decreed. The centre of protected areas (whether or not it corresponds to core areas) had a lower rate
of forest cover loss. Population and road density was significantly lower within than outside protected areas and in regulated
core areas than in the rest of the area. Isolation from the boundary appears to reduce deforestation as much as the presence
of regulated core areas, illustrating the importance of size and design and the importance of protecting large areas with
adequate core areas for a more effective conservation management. 相似文献
3.
The under-financing of protected areas in the Congo Basin: so many parks and so little willingness-to-pay 总被引:1,自引:0,他引:1
Protected areas in the Congo Basin cover approximately 6% of the landscape, and several international NGOs are proposing substantial additions to the present network of parks and reserves. Yet, chronic under-funding has long precluded effective management of most parks and reserves resulting in their progressive ecological impoverishment, and the loss of biodiversity. Furthermore, not only are the indebted nations of the Congo Basin not in a position to contribute significantly to cover the recurring costs of protected area management, the growing opportunity costs of setting aside protected areas is increasing the incentives to local communities and national governments to 'illegally' exploit economically valuable resources within parks and reserves. If the global value of the biodiversity contained within the Congo Basin is considered worth preserving then donors and international NGOs must work with national governments to reach consensus on an optimal protected area network that (a) contains a representative assemblage of forest species; (b) is composed of forest blocks that are sufficiently large, intact, and likely to persist; (c) contains zones of active speciation (e.g. ecotones), and (d) can expect to receive sufficient long-term financial support to ensure effective management. Given the 'need to eat today' reality of economies in the Congo Basin, the international community must decide to shoulder most of the costs of conservation of globally important biodiversity. If donors continue to under-finance protected areas rather than make the hard choices associated with prioritizing protected area spending then most if not all protected areas within the Congo Basin will continue to exhibit reductions in the biomass of individual species, and risk the extirpation or extinction of large, slow reproducing species, and rare endemics. 相似文献
4.
Jane E. Bryan Philip L. Shearman Gregory P. Asner David E. Knapp Geraldine Aoro Barbara Lokes 《PloS one》2013,8(7)
The Malaysian states of Sabah and Sarawak are global hotspots of forest loss and degradation due to timber and oil palm industries; however, the rates and patterns of change have remained poorly measured by conventional field or satellite approaches. Using 30 m resolution optical imagery acquired since 1990, forest cover and logging roads were mapped throughout Malaysian Borneo and Brunei using the Carnegie Landsat Analysis System. We uncovered ∼364,000 km of roads constructed through the forests of this region. We estimated that in 2009 there were at most 45,400 km2 of intact forest ecosystems in Malaysian Borneo and Brunei. Critically, we found that nearly 80% of the land surface of Sabah and Sarawak was impacted by previously undocumented, high-impact logging or clearing operations from 1990 to 2009. This contrasted strongly with neighbouring Brunei, where 54% of the land area remained covered by unlogged forest. Overall, only 8% and 3% of land area in Sabah and Sarawak, respectively, was covered by intact forests under designated protected areas. Our assessment shows that very few forest ecosystems remain intact in Sabah or Sarawak, but that Brunei, by largely excluding industrial logging from its borders, has been comparatively successful in protecting its forests. 相似文献
5.
Kathrin D. Wagner Jochen Krauss Ingolf Steffan-Dewenter 《Journal of Insect Conservation》2013,17(5):1039-1046
Land cover and climate change are both major threats for biodiversity. In mountain ecosystems species have to adapt to fragmented habitats and harsh environmental conditions but so far, altitudinal effects in combination with land cover change have been rarely studied. The objective of this study was to determine the effects of altitude and historical land cover change on butterfly diversity. We studied species richness patterns of butterflies occuring in wetlands and other open habitats along an altitudinal gradient in a low mountain region (340–750 m a.s.l., Bavaria, Germany) with drastic loss of open habitats within the last 40–60 years. We recorded in 27 sites a total of 4,523 individuals of 49 butterfly species and five species of burnet moths. Species richness peaked at mid elevation and increased with patch size. Land cover change was most pronounced at high altitudes, but neither current open habitats, nor the historical loss of open habitats affected the species richness of butterflies. Neither open land specialized butterflies nor generalist and forest species were significantly affected by the loss of open habitats. However, increasing forest area in high altitudes reduces possible refuge open habitats for butterflies at their thermal distribution limits. This could lead to extinction of such butterfly species when temperatures further rise due to global warming. 相似文献
6.
Claus B?ssler J?rg Müller Miroslav Svoboda Anna Lep?ová Christoph Hahn Heinrich Holzer Václav Pouska 《Biodiversity and Conservation》2012,21(1):33-49
Rapid destruction of forest habitats has led to the establishment of protected areas in formerly managed forests with the
aim of restoring biodiversity. Conservation in spruce-dominated reserves is often contradicted by salvage logging after insect
outbreaks. Here we study the community characteristics of wood decaying fungi in a high montane Norway Spruce forest with
three different management types: (1) a formerly managed area disturbed by a large-scale bark beetle outbreak, (2) an area
with continuous salvage logging, and (3) an old-growth forest. Bark beetle activity in the disturbed area resulted in downed
wood amounts comparable to those of the old-growth forest. However, species accumulation curves for the disturbed forest were
more similar to those of the logged forest than to those of the old-growth forest. This arose because of differences in the
diversity of wood decay classes; wood decay in the disturbed forest was more homogeneous. Logs in the disturbed forest originated
almost exclusively from bark-beetle-infested trees, but the causes of tree mortality in the old-growth forest were manifold.
Although most red-listed species were clearly confined to old-growth forest, Antrodiella citrinella was most abundant in the disturbed forest. Our analysis furthermore showed that the between stand scale is the most effective
unit for diversity wood-decaying fungi. We therefore suggest a conservation strategy for preserving old-growth forests and
establishing protected forest stands to enhance structural heterogeneity in spruce-dominated forests. For this, a careful
screening of protected areas throughout Europe is necessary to provide managers with guidelines for conservation. 相似文献
7.
Normunds Prieditis 《Biodiversity and Conservation》2002,11(8):1361-1375
Since the 1990s the forest conservation system in Latvia has developedin two parallel trends. This reflects both traditional application ofcentral European phytosociology by explicit forest communities (at least 19 associations inLatvian forests) and the recently appreciated method of key-habitats in forests.It consists of two attributes: indicator species–habitat specialists andcertain abiotic structures whose persistent presence on the spot is limited byintactness, time-scale and natural disturbances. Following the interpretationmanual of habitats in the European Union, eight forest habitats deserve particularconservation in Latvia. Altogether 8% of Latvian forests are formally protected,although only 1.5% meet the World Conservation Union Category 1where all human intervention must be excluded or minimized. Original analysis ofLatvian forest communities by their phytosociological standard and a comparisonwith similar assemblages elsewhere suggest that four forest groups deserveall-European conservation priority in Latvia because of intactness and largestands still survived or because of narrow distribution area. These are:Alnus glutinosa–Betula spp.–Fraxinus excelsior wetlands (ca. 3000 ha invarious formal reserve networks), northern outposts of mixed riverine hardwoodforests on the bank slopes and in semi-permanently moist ravines (ca. 240ha in reserves), floodplain and riverine Quercusrobur relic woodlands in eastern Latvia (ca. 120 ha inreserves) and dry Fennoscandian–Baltic Pinussylvestris woodlands on dolomites and limestones (no areas formallyprotected by law yet). Preliminary inventory of woodland key-habitats suggeststhat only 3% of Latvian forests can meet the desired criteria. This method,based on 53 indicator species indicating certain habitat properties and 25abiotic structures and stand features, has been found a valuable tool inforestry practice to evaluate the forest before any logging takes place and tomonitor spatial changes of biodiversity. 相似文献
8.
Habitat loss is the main driver of the current biodiversity crisis, a landscape-scale process that affects the survival of spatially-structured populations. Although it is well-established that species responses to habitat loss can be abrupt, the existence of a biodiversity threshold is still the cause of much controversy in the literature and would require that most species respond similarly to the loss of native vegetation. Here we test the existence of a biodiversity threshold, i.e. an abrupt decline in species richness, with habitat loss. We draw on a spatially-replicated dataset on Atlantic forest small mammals, consisting of 16 sampling sites divided between forests and matrix habitats in each of five 3600-ha landscapes (varying from 5% to 45% forest cover), and on an a priori classification of species into habitat requirement categories (forest specialists, habitat generalists and open-area specialists). Forest specialists declined abruptly below 30% of forest cover, and spillover to the matrix occurred only in more forested landscapes. Generalists responded positively to landscape heterogeneity, peaking at intermediary levels of forest cover. Open area specialists dominated the matrix and did not spillover to forests. As a result of these distinct responses, we observed a biodiversity threshold for the small mammal community below 30% forest cover, and a peak in species richness just above this threshold. Our results highlight that cross habitat spillover may be asymmetrical and contingent on landscape context, occurring mainly from forests to the matrix and only in more forested landscapes. Moreover, they indicate the potential for biodiversity thresholds in human-modified landscapes, and the importance of landscape heterogeneity to biodiversity. Since forest loss affected not only the conservation value of forest patches, but also the potential for biodiversity-mediated services in anthropogenic habitats, our work indicates the importance of proactive measures to avoid human-modified landscapes to cross this threshold. 相似文献
9.
Sue Baker Leon Barmuta Simon Grove Alastair Richardson 《Biodiversity and Conservation》2009,18(13):3467-3482
Reservation of forest in riparian buffers is common practice in commercial forestry areas worldwide, potentially providing
valuable habitat for biodiversity dependent on mature forest. However, the habitat value of narrow reserve corridors can be
compromised by edge effects. We investigated the habitat value of streamside buffers in wet eucalypt forest for ground-dwelling
beetles in Tasmania, Australia. Beetles were collected with pitfall traps in five replicates of four habitats: unlogged corridors
of mature forest in streamside reserves (buffers) with clearfelling-derived logging regeneration either side; continuous mature
upslope forest; continuous mature riparian forest; and <20-year-old upslope clearfelling-derived logging regeneration. Streamside
reserve widths on each side of the stream were on average 40 ± 6 m (±95% CI) from reserve edge to stream. Beetle assemblages
in logging regeneration differed substantially from those in the unlogged habitats, including the streamside reserves. Streamside
reserve assemblages nevertheless differed from those of the continuous unlogged areas. Assemblage composition in streamside
reserves was most similar to that in continuous mature riparian forest, although beetle diversity was higher in the reserves.
Our results suggest that although streamside reserves provide habitat for the majority of commonly collected beetle species
occurring in continuous mature forest, wider reserve corridors in the wet eucalypt forests of Tasmania may be required to
provide habitat that is not edge-affected. 相似文献
10.
Past levels of canopy closure affect the occurrence of veteran trees and flagship saproxylic beetles
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Jan Miklín Pavel Sebek David Hauck Ondrej Konvicka Lukas Cizek 《Diversity & distributions》2018,24(2):208-218
Aim
Open woodlands are biologically highly diverse habitats, and veteran (i.e., old, senescent) trees are key structures supporting their biodiversity. Open canopy structure had been maintained by both natural‐ and human‐induced disturbances. In the past two centuries, suppression of such disturbances, together with forestry intensification, has turned most lowland woodlands into closed‐canopy forests. We investigated the effect of increased canopy closure on veteran trees and several threatened beetles associated with them.Location
Floodplain woodlands along the lower Dyje and Morava rivers, Czech Republic.Methods
We used an approach combining the study of aerial photographs with on‐ground survey of veteran trees and associated endangered beetles. The aerial images were used to obtain the information on historical (1938) and recent (2009) canopy closure in the area of 146 km2, where we mapped large oaks (d.b.h. >70 cm), hollow trees and three associated beetles including the hermit beetle (Osmoderma barnabita), the great capricorn beetle (Cerambyx cerdo) and the jewel beetle Eurythyrea quercus.Results
The presence of large oaks, hollow trees and their associated beetle species are negatively related to recent high canopy closure, and the historical level of canopy closure matters, as in nowadays closed‐canopy stands, the beetles and veteran trees are more common in places that were rather open in 1938 than in the places with closed canopy already in 1938. Moreover, the health state of veteran trees highly depends on the canopy closure.Main conclusion
The negative effect of canopy closure on veteran trees and their endangered inhabitants is several decades delayed and may thus often go undetected. In the forests, however, large and hollow trees and their associated biodiversity are relics of the past, more open conditions. The restoration of open woodlands is therefore vital for preventing their further decline. Conservation management planning needs to take this into account wherever, veteran trees and associated biota are concerned.11.
Anthropogenic disturbances have serious impacts on ecosystems across the world. Understanding the effects of disturbance on woodlands, especially in regions where local people depend on these natural resources, is essential for sustainable natural resource management and biodiversity conservation. In this study, we evaluated the effects of anthropogenic disturbance, specifically selective logging of Brachystegia floribunda, on woodlands by comparing species composition, species diversity and functional diversity of woody plants between disturbed and undisturbed woodlands. We combined species data and functional trait data for leaves, fruits and other traits related to resource and disturbance responses to calculate functional indices (functional richness, evenness and divergence) and community‐weighted means of each trait. Shifts in taxonomic species composition were analysed using nonmetric multi‐dimensional scaling. Species composition differed significantly between disturbed and undisturbed woodlands. Tree density was greater in disturbed woodlands, whereas evenness, functional evenness and functional divergence were greater in undisturbed woodlands. In terms of forest cover, selective logging of B. floribunda appeared to have little impact on Miombo woodlands, but some shifts in functional traits, such as the shift from a deciduous to evergreen phenology, may increase the vulnerability of these ecosystems to environmental change, especially drought. 相似文献
12.
Masahiro Ichikawa 《Ecological Research》2007,22(3):403-413
Swidden agriculture, commercial logging and plantation development have been considered to be the primary common causes of
degradation and loss of tropical rain forests in Southeast Asia. In this paper, I chose a part of northeastern Sarawak, East
Malaysia as my case study area to analyze the changes in its land-use characteristics. In the study area, as well as primeval
forests, we see that land use began about 100 years ago by a native group called the Iban; commercial logging began in the
1960s, and the development of oil palm plantations began recently. I describe the changes in land use as well as their social
and economic causes by referring to aerial photographs, literature surveys, interviews with government officers and the Iban,
and observation of land use. My analysis of land use demonstrates that on “state land”, where commercial logging and oil palm
plantation development are occurring, large areas of forest have been disturbed in a short period of time. The objective is
to benefit economically in response to the social and economic conditions surrounding the study area. On the other hand, in
the “Iban territory,” where the Iban practice their land use, land conversion has not occurred on a large scale and in a short
period of time, even though the forest has been cut and agricultural fields have been created in response to social and economic
conditions as well. They disperse small agricultural fields throughout their forest land. Therefore, the landscape of the
“Iban territory” is based on secondary forest, composed of patches of forest in various stages and with several types of agricultural
land. Today in Sarawak, monocrop plantations are rapidly expanding and little primeval forest remains. Given these conditions,
the land-use practices of natives such as the Iban will be evaluated from the viewpoint of ecosystem and biodiversity conservation.
It could play an important role in providing habitats for natural wildlife. 相似文献
13.
Networks of protected areas are a key component of efforts to conserve biodiversity. However, there are concerns about an uncritical focus on the percentage area of reserves without an assessment of how well formal reserves are actually protecting biodiversity. In response, we completed a spatial analysis of the formal reserve system in the Australian state of Victoria. We quantified how well the reserve system captured a crude surrogate for vegetation communities (viz: Ecological Vegetation Classes) as well as distribution models for an array of threatened forest‐dependent species. We found evidence of a high degree of overlap between areas subject to intensive forestry (clearcutting) operations and the modelled distribution of a suite of forest‐dependent species. A key outcome of our study was that areas around sites subject to past logging as well as new areas proposed for logging under the Timber Release Plan in Victoria had significantly higher values for threatened forest‐dependent species (as determined by habitat distribution models) than areas that had not been logged. We found significant differences in the spatial characteristics of the dedicated reserve systems and informal protected area networks, with the latter featuring much of its area close to a tenure boundary where logging occurs. Our empirical analyses demonstrating the impacts of ongoing logging operations on areas with high environmental suitability for threatened species have important implications. In particular, the current reserve system is inadequate for a suite of forest‐dependent taxa, including critically endangered Leadbeater's Possum (Gymnobelideus leadbeateri) and the vulnerable Greater Glider (Petauroides volans). This suggests a high degree of conflict between areas of high value for conservation and areas targeted for wood production. 相似文献
14.
Land abandonment is causing woodland expansion and loss of open habitats in the Alps, coupled with a shift in forestry practices
from coppice management to high forest. Despite such rapid large-scale changes, there has been very little investigation of
the environmental predictors of biodiversity in the Alpine landscape. We assessed the richness of amphibians, reptiles and
breeding birds (n = 189 species), used as a surrogate of biodiversity, in 58 quadrats of 100 km2, located within a well surveyed area of the province of Trento (central-eastern Italian Alps). The surrogates were then related
to a series of environmental variables by means of stepwise multiple regression. Depending on the surrogate analysed, species
richness declined linearly or quadratically with elevation, and increased with habitat heterogeneity and the availability
of grassland and arid-rocky habitats. The same results were obtained when incorporating a measure of species threat into the
biodiversity estimates. Different surrogates were positively inter-correlated, probably because of a common response to the
same factor, namely elevation, which was the only variable to enter all models. Such elevational gradient produced a clear
biodiversity peak in low-elevation areas, generating potential conflict between efficient biodiversity conservation and economic
interests linked to human development, a scenario which probably applies to many mountain regions worldwide. The current network
of protected areas was quite satisfactory in terms of area covered but biased towards high-elevation areas, of high scenic
beauty but relatively low in animal biodiversity value. Low-elevation reserves were small and isolated. Proposed conservation
targets include the establishment of corridors increasing the connectivity of low-elevation reserves and the promotion of
incentives for the extensive management of grassland, an agro-ecosystem of high historical and biological value. 相似文献
15.
基于生物多样性与生态系统服务功能的秦岭山系自然保护体系规划 总被引:2,自引:0,他引:2
生物多样性与生态系统服务是目前生态保护的两大主要目标,在保护区体系规划设计中兼顾两个保护目标有助于发挥自然保护区的综合效益。以生物多样性与生态系统服务功能都重要的秦岭山系为研究区域,在生物多样性、水源涵养和土壤保持重要性评估的基础上,通过空缺分析,提出了秦岭山系的保护区体系优化方案。研究结果表明,现有的自然保护区保护了33.5%的生物多样性极重要区,22.9%的水源涵养极重要区,但是只保护了7.4%的土壤保持极重要区;建议在秦岭主峰、秦岭西部和东南部分别建立自然保护区群和生态功能保护区,保护区面积占秦岭山系总面积的31.4%,使生物多样性、水源涵养、土壤保持的极重要区的保护比例达76.2%、70.5%和41.5%,生态保护效益得到提升。研究结果可以为秦岭山系生态保护政策的制定提供参考,同时对于其他地区自然保护体系规划、以及国家公园构建也具有重要的借鉴意义。 相似文献
16.
Jean-Marc Thiollay 《Biodiversity and Conservation》2002,11(8):1377-1395
The unbroken primary rain forest currently covering the interior ofFrench Guiana still offers a unique opportunity to establish a network of largeprotected areas. Bird species richness was surveyed within 20 study areasspreadover the country to assess the relative abundance and frequency of occurrenceofforest interior and natural gap taxa (391 species, excluding raptors andnon-resident birds). Richness, rarity, restricted range, hot spot andconservation value algorithms were used to rank sites in decreasing orders ofimportance and draw sets of survey sites likely to maximize bird diversity. Inmost sets from different methodological approaches, the southern regionconsistently emerged as a priority area for conservation, with the centralmountain range contributing some specialized taxa and the northern regionincorporating additional species, mostly from marginal habitats and moretypicalof the nearby coastal zone. Estimates of areas likely to preserve an almostcomplete sample of the regional biodiversity amounted to about 1–2millionhectares, either in one large area (national park) or divided into 2–3reserves overlapping regional hot spots. However, representation of all speciesand habitats in a protected area system is not an assurance of long-termviability when minimum viable population sizes and demographic patterns arelittle known, and when the risks and impacts of persistent human disturbancessuch as mining, logging and hunting are growing. 相似文献
17.
Aim Our two main goals are first to evaluate the resilience of the boreal forest according to latitude across the closed‐crown forest zone using the post‐disturbance distribution and cover of lichen woodlands and closed‐crown forests as a metric, and second to identify the disturbance factors responsible for the regeneration and degradation of the closed‐crown forest according to latitude since the 1950s. Location The study area extends between 70°00′ and 72°00′ W and throughout the closed‐crown forest zone, from its southern limit near 47°30′ N to its northern limit at the contact with the lichen woodland zone at around 52°40′ N. Methods Recent (1972–2002) and old (1954–1956) aerial photos were used to map the distribution of lichen woodlands across the closed‐crown forest zone. Forest disturbances such as fire, spruce budworm (Choristoneura fumiferana (Clemens)) outbreak, and logging were recorded on each set of aerial photos. Each lichen woodland and stand disturbance was validated by air‐borne surveys and digitized using GIS software. Results Over the last 50 years, the area occupied by lichen woodlands has increased according to latitude; that is, 9% of the area that was occupied by closed‐crown forests has shifted to lichen woodlands. Although logging activities have been concentrated in the same areas during the last 50 years, the area covered by logging has increased significantly. Outbreaks by the spruce budworm occurred predominantly in the southern (47°30′ N to 48°30′ N) and central (48°53′ N to 50°42′ N) parts of the study area, where balsam fir stands are extensive. In the northern part of the study area (51°–52°40′ N), extensive fires affected the distribution and cover of closed‐crown forests and lichen woodlands. Main conclusions Over the last 50 years, the area occupied by closed‐crown forests has decreased dramatically, and the ecological conditions that allow closed‐crown forests to establish and develop are currently less prevalent. Fire is by far the main disturbance, reducing the ability of natural closed‐crown forests to self‐regenerate whatever the latitude. Given the current biogeographical shift from dense to open forests, the northern part of the closed‐crown forest zone is in a process of dramatic change towards the dominance of northern woodlands. 相似文献
18.
Woody vegetation composition and diversity in woodlands inside and outside a Forest Reserve in Jos,Nigeria
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Iveren Abiem Sonali Saha Shiiwua A. Manu Emmanuel B. Elisha 《African Journal of Ecology》2018,56(2):202-207
Protected areas such as forest reserves are often assumed to be best ways to conserve biodiversity and maintain intact ecosystems. We examined woody plant composition and diversity in the gallery forest and savannah woodland habitats of Amurum Forest Reserve and areas immediately surrounding it in Jos, Nigeria. A total of 100 10 × 10 m sample plots were established inside and outside the reserve. All woody plants ≥1 cm diameter at breast height (dbh) were identified and measured. A total of 7,564 individual plants categorized as 134 species from 44 families were recorded. Overall species diversity was significantly higher in the Forest Reserve than outside the reserve, although more species were encountered outside the reserve. Our findings suggest that, protected areas and the areas surrounding them are important for the conservation of biodiversity as the areas outside protected areas also contain species of conservation value. The continuous degrading areas outside protected areas isolates them and poses a serious threat to the long‐term viability of wildlife populations, so it is important that biodiversity in protected areas and their surrounding areas be conserved. 相似文献
19.
Multi‐scale effects of habitat structure and landscape context on a vertebrate with limited dispersal ability (the brown‐throated sloth,Bradypus variegatus)
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As human population, food consumption, and demand for forest products continue to rise over the next century, the pressures of land‐use change on biodiversity are projected to intensify. In tropical regions, countryside habitats that retain abundant tree cover and structurally complex canopies may complement protected areas by providing suitable habitats and landscape connectivity for a significant portion of the native biota. Species with low dispersal capabilities are among the most at risk of extinction as a consequence of land‐use change. We assessed how the spatial distribution of the brown‐throated sloth (Bradypus variegatus), a model species for a vertebrate with limited dispersal ability, is shaped by differences in habitat structure and landscape patterns of countryside habitats in north‐central Costa Rica using a multi‐scale framework. We quantified the influence of local habitat characteristics and landscape context on sloth occurrence using mixed‐effects logistic regression models. We recorded 27 sloths within countryside habitats and found that both local and landscape factors significantly influenced their spatial distribution. Locally, sloths favored structurally complex habitats, with greater canopy cover and variation in tree height and basal area. At the landscape scale, sloths demonstrated a preference for habitats with high proportions of forest and nearby large tracts of forest. Although mixed‐use areas and tree plantations are not substitutes for protected forests, our results suggest they provide important supplemental habitats for sloths. To promote the conservation and long‐term viability of sloth populations in the tropical countryside, we recommend that land managers retain structurally complex vegetation and large patches of native habitat. 相似文献
20.
Thomas W. Gillespie Boris Lipkin Lauren Sullivan David R. Benowitz Stephanie Pau Gunnar Keppel 《Biodiversity and Conservation》2012,21(14):3597-3611
The goal of biodiversity hotspots is to identify regions around the world where conservation priorities should be focused. We undertake a geographic information system and remote sensing analysis to identify the rarest and least protected forests in biodiversity hotspots. World Wildlife Fund ecoregions with terrestrial forest were subset from 34 biodiversity hotspots and forest cover calculated from GlobCover data at a 300?m pixel resolution. There were 276 ecoregions in 32 biodiversity hotspots classified as containing terrestrial forests. When the first quartile of forest ecoregions was subset based on smallest extent of forest cover in protected areas, there were 69 rare forests identified within 20 biodiversity hotspots. Most rare forest ecoregions (45) occurred on islands or island archipelagos and 47 rare forest ecoregions contained less than 10?% forest cover in protected areas. San Félix-San Ambrosio Islands Temperate Forests, Tubuai Tropical Moist Forests, Maldives-Lakshadweep-Chagos Archipelago Tropical Moist Forests, and Yap Tropical Dry Forests were identified as the least protected and possibly most vulnerable forests within biodiversity hotspots. These ecoregions cover less than 500?km2, forest cover is less than 50?km2, and there are no protected areas. There is a need to update classifications and boundaries of protected areas, insure that islands are included in global land cover datasets, and identify levels of endemism and endangerment within forest ecoregions. This should improve our ability to compare, prioritize, and monitor forests in biodiversity hotspots. 相似文献