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1.
The forests and highlands along the southern portion of the Nigeria-Cameroon border and on the island of Bioko have long been recognized as being biologically diverse. This region (referred to as the Biafran forests and highlands) is a center of endemism for a wide variety of taxa including, but not limited to, primates, anuran amphibians, birds, freshwater fish, butterflies, dragonflies, and trees. Though these groups have diverse distributions, conservation efforts have to date largely been focused on lowland areas. We conducted a GIS-based analysis of point locality records for three groups characterized by high endemism (primates, anuran amphibians, birds) in order to examine both their spatial and altitudinal distribution throughout the study area. We also evaluated the distribution of existing and potential protected areas relative to highland areas and the distribution of endemics. Our analysis suggests that the existing protected area system provides poor coverage of montane habitats and their associated endemic taxa. Complementarity analysis suggests that, if the protected area network were expanded to include a small number of highland sites, coverage of endemic taxa could be significantly improved. Many of these important highland sites are currently under intense pressure from habitat loss and hunting. If the full range of biodiversity present in the Biafran forests and highlands is to be preserved, new protected areas should be gazetted that take the varied distributions of the regions endemic taxa into account.  相似文献   

2.
With the rapid conversion of tropical forests in Asia to plantation forests for timber or biofuel production there is a need to determine if these forests serve any viable role in wildlife conservation. We used infra-red trip cameras to survey for large terrestrial mammals within an Acacia/secondary forest matrix being created for pulpwood production in Sarawak, Malaysia. We detected at least 27 species of mammals within the matrix and 18 species were detected in both Acacia and secondary forest. Using occupancy modeling to determine important covariates for seven mammal species within the project area, six of these species were sensitive to forest type, and most were sensitive to the amount of secondary forest within 1 km of the sample point. For four species (sun bear, Helarctos melayanus; common porcupine, Hystrix brachyura; mousedeer, Tragulus spp.; and pig-tailed macaque, Macaca nemestrina), the mean distance of detection from large secondary forest blocks was significantly closer than expected from the distribution of sample points. Most species used Acacia forest less frequently than secondary forest, possibly for transit or foraging, with the exception of bearded pigs (Sus barbatus), sambar (Rucervus unicolor), and civets which were more common in Acacia stands. The amount of secondary forest preserved within forest plantations seems to be the best measure of conservation potential for these industrial forests. Forest plantations can provide a conservation value if managed properly and those retaining significant amounts of secondary forest should be eligible for a base level of certification as they comprise a significant portion of the landscape in this region.  相似文献   

3.
Traditional biodiversity conservation approaches emphasize the protection of pristine forests. However, it has become increasingly difficult to secure large tracts of undisturbed forests, particularly in the developing tropics. This has led some conservation scientists and organizations to explore the conservation potential of human-modified habitats, such as selectively logged forests. On the other hand, other scientists have highlighted the perils of overselling the conservation value of degraded habitats and advocate for re-focusing of efforts and resources on protecting primary forests. While there are merits to both contentions, we argue that the “back to wilderness” paradigm has limited relevance in the Sundaland region. This is because: (1) primary forest only makes up a small minority of the remaining forest in the region and most of it is already protected by law; (2) vast areas of selectively logged forest are still susceptible to plantation conversion; and (3) selectively logged forest are important habitats for some of the world’s most endangered species. To meet both conservation and development goals, we suggest that tracts of selectively logged forest be assessed for their ecological value and forests of high conservation value be prioritized for better protection through their inclusion into existing protected area networks and/or improved sustainable forestry management.  相似文献   

4.
In India, conservation of biodiversity goes hand in hand with human welfare, as millions of people live adjacent or within protected areas and depend upon forests products. The high density and biomass requirements of these households could result in the degradation of forests and loss of biodiversity. We assessed the collection of forest products among households in five sites in the Western and Eastern Ghats of peninsular India: the Kogar region of the Central Western Ghats, the Bandipur and Sigur regions of the Nilgiri Biosphere Reserve, the Kalakad-Mundanthurai Tiger Reserve of the southern Western Ghats and Similipal Tiger Reserve of the northern Eastern Ghats, and tested whether extraction pressure on forests was associated with the proportion of agricultural households, wage labour and population density. We also examined whether data on loss of cover as stated by the State of the Forest Reports was supported by field data. The regions differed in land use: Kogar, KMTR and Similipal were primarily agricultural regions, whereas households engaged in wage labour or in running small businesses were predominant in Sigur and Bandipur. Fuel-wood was collected ubiquitously for household use in all sites, used mainly for domestic requirements and secondarily for generating income. Green leaves for making fertilizer and fodder were collected for household use and did not enter the market. Cattle manure for the global organic coffee industry was a major forest product in Bandipur and Sigur. Extraction pressure on forests was positively associated with the availability of wage labour and was negatively with the proportion of agricultural households. Data from official sources seem inadequate to measure forest degradation in protected forests. Accurate estimation of forest condition through field assessments and remote sensing, and understanding the socio-economic variables associated with forest loss and degradation are needed for the sustainable management of Indian protected areas.  相似文献   

5.
Biodiversity conservation issues are often contentious and complex. Polarized debates on the effectiveness of protected areas and role of people inside them, charismatic species as conservation foci, and on specific policy initiatives are common among Indian and global conservationists. We surveyed Indian conservationists about the conservation effectiveness of protected areas and charismatic species, as well as status of conservation and research efforts. We expected differences among people based on professional affiliation, and educational background. We examined participants’ opinions on conservation policies like Project Tiger and Elephant, the Forest Rights Act, and the Tiger Task Force Report. Participants ranked Indian research efforts as average, and identified a bias towards terrestrial species and ecosystems. Ninety-percent of participants considered reserves to be effective, many (61%) participants felt that the situation of people living inside reserves is unsustainable, and many (76%) felt the use of force to protect reserves from illegal human activities is acceptable. Classification and regression tree models for these questions suggested that non-academics were more likely than academics to agree with these positions. On the success of Project Tiger and Elephant, older participants were more likely to think these initiatives were a success. Many (63%) participants felt the Forest Rights Act needed revision, particularly if they had doctoral degrees. Sixty-two percent of participants did not think Tiger Task Force was effective. Overall, participants’ professional affiliation, age, and academic degree were important predictors of participants attitudes towards conservation initiatives.  相似文献   

6.
A study has been made of the population ecology of large mammals of Silent Valley and contiguous forests of South India. The vegetation of Silent Valley and Attapadi forests are mostly west coast tropical evergreen and semi-evergreen types. In the adjoining forests Nilambur and Nilgiris, the vegetation is southern secondary moist mixed deciduous and southern montane wet temperature, respectively. Silent Valley and its contiguous forests harbour 25 species of large and medium-sized mammals, including two endangered endemic species and many others that are endangered and protected. The lion-tailed macaque, Nilgiri tahr and tiger were sighted in and around the submergence area of the proposed Silent Valley hydroelectric project. If constructed, the impact of this dam on the populations of larger mammals in the area would be severe.  相似文献   

7.
The genetic resources of Allium in India are potential source of genes for widening the crop genetic base. Despite their high economic value, limited number of germplasm accessions of wild species have been collected and conserved mainly due to difficult access to areas of occurrence. The present work mainly highlights information on species diversity distribution and utilization of wild Allium species to assess the value of Indian germplasm and prioritization for future collection and conservation programmes.  相似文献   

8.
Hunting with firearms decimates primates of large and medium body size (>2 kg) that disperse the seeds of large-seeded trees. In continuous, un-fragmented forests of southeastern Peru regularly hunted with firearms for 30-40 years, large primates are extirpated and medium-sized (medium) primates are reduced 61% compared with protected forests. At hunted sites seedlings and small juveniles (<1 m height) of trees dispersed by primates heavier than 2 kg are reduced 46%, a loss of one species m−2, and abiotically-dispersed plants are 284% more common, adding eight individuals m−2, compared with protected forests. Here we provide evidence consistent with the long-held prediction that commercial hunting changes plant communities. We show that the composition of seedling and small juvenile tree communities that ultimately regenerate future forests differs markedly in forests hunted with firearms compared with protected forests. This opens the possibility of shifts in tree species composition, even in hunted forests that are not logged or fragmented, towards forests dominated by trees dispersed by wind or non-game animals.  相似文献   

9.
Due to its practical relevance to conservation, considerable efforts have been devoted to understanding the effects of logging on orangutan (Pongo spp.) population densities. Despite these efforts, consistent patterns have yet to emerge. We conducted orangutan nest surveys and measured forest quality and disturbance level at 108 independent locations in 22 distinct sites in the forests of the Berau and East Kutai regencies of East Kalimantan, Indonesia. Survey locations varied substantially in orangutan density, forest structure, distance to villages, and logging intensity. We incorporated site-specific nest tree composition into our estimates of nest decay rates to reduce errors associated with inter-site differences in nest tree selection. Orangutan nest densities were uncorrelated with altitude, fig density, or any other ecological measure. Multivariate analyses demonstrated that densities were not significantly affected by logging intensity (at the relatively light levels we report here) or the distance to the nearest village, but were positively correlated with the distance from the nearest village known to hunt orangutans. These results indicate that provided hunting is absent, lightly to moderately degraded forests retain high conservation value for orangutans. Widespread incorporation of degraded areas into management plans for orangutan populations would substantially increase the size of populations that could be protected, and thereby improve their changes for long-term survival.  相似文献   

10.
Fragmentation of old-growth forests and greatly reduced amounts of coarse dead wood in managed forests threat the persistence of many saproxylic species in boreal Fennoscandia. Individual old-growth forest remnants may lose species over time as they pay off their extinction debt. We tested this by comparing the observed site occupancy of individual wood-inhabiting fungal species in isolated old-growth stands (i.e. woodland key habitats; WKHs) with statistical predictions of their occupancy assuming potential extinction debt had already been paid off. The occupancy of species was analysed in two sets of WKHs differing in time since isolation (i.e. recent and old isolates).Few species occurred more frequently than expected in WKHs. However, patterns across species and across all WKHs masked important differences among species in their risk of facing future extinction. The site occupancy decreased significantly between recent and old isolates for a group of annual, red-listed specialist fungal species, suggesting that an extinction debt in WKHs may exist among specific species confined to coarse dead wood and old-growth forest habitat. Generalist species that also occur in the surrounding matrix showed no negative trends, or actually increased in site occupancy, making future extinctions less likely. Thus, continuing loss of threatened species are likely if not preservation of WKHs are combined with other conservation efforts in managed forest landscapes. Natural forest landscapes may serve as important references when aiming to identify species in risk of future extinction but more detailed knowledge about the biology of the most vulnerable species is also required.  相似文献   

11.
Tropical mammals represent some of the most threatened species, but also the least known because they tend to be difficult to study. To objectively evaluate the conservation status of these species, standardized methods are urgently required. The sun bear Helarctos malayanus is a case in point: it is cryptic, difficult to detect and consequently classified on the IUCN Red List as Data Deficient, and the highest priority for bear conservation research. In this study, we apply a detection/non-detection sampling technique using camera trap data with environmental covariates to estimate sun bear occupancy from three tropical forest study areas with different levels of degradation and protection status in Sumatra. Sun bear detections, and encounter rates, were highest in one of the primary forest study areas, but sun bear occupancy was highest in the degraded forest study area. Whilst, sun bears were recorded at a greater proportion of camera placements in degraded forest, these records were often on only one occasion at each placement, which greatly increased the final occupancy estimate. Primary forests with their large fruiting trees undoubtedly represent good sun bear habitat, but our results indicate that degraded forest can also represent important habitat. These forests should therefore not be considered as having limited conservation value and assigned to other uses, such as oil palm production, as has previously happened in Sumatra. Estimating occupancy between years will yield information on the population trends of sun bears and other tropical mammals, which can be used to provide more reliable conservation assessments.  相似文献   

12.
Hunting and habitat degradation are universal threats to primates across the tropics, thus deciphering the relative impact of threats on population relative abundance is critical to predicting extinction risk and providing conservation recommendations. We studied diurnal primates over a period of nearly 6 years in the Udzungwa Mountains of Tanzania, a site of global importance for primate conservation. We assessed how population relative abundance of five species (of which two are endemic and IUCN-Endangered) differed between two forest blocks that are similar in size and habitat types but contrast strongly in protection level, and how abundance changed during 2004–2009. We also measured habitat and disturbance parameters and, in the unprotected forest, evaluated hunting practices. We found significant differences in primates’ abundance between protected and unprotected forests, with the greater contrast being the lower abundance of colobine monkeys (Udzungwa red colobus and Angolan colobus) in the unprotected forest. At this site moreover, colobines declined to near-extinction over the study period. In contrast, two cercopithecines (Sanje mangabey and Sykes’ monkey) showed slightly higher abundance in the unprotected forest and did not decline significantly. We argue that escalating hunting in the unprotected forest has specifically impacted the canopy-dwelling colobus monkeys, although habitat degradation may also have reduced their abundance. In contrast, cercopithecines did not seem affected by the current hunting, and their greater ecological adaptability may explain the relatively higher abundance in the unprotected forest. We provide recommendations towards the long-term protection of the area.  相似文献   

13.
Large mammals face high risks of anthropogenic extinction owing to their larger body mass and associated life history traits. Recent worldwide mammal declines have highlighted the conservation importance of effective assessments of trends in distribution and abundance of species. Yet reliable data depicting the nature and extent of changes in population parameters is sparse, primarily due to logistical problems in covering large areas and difficulties in obtaining reliable information at large spatial scales, particularly over time. We used key informant surveys to generate detection histories for 18 species of large mammals (body mass > 2 kg) at two points in time (present and 30 years ago) in the Southern subregion of the Western Ghats global biodiversity hotspot. Multiple-season occupancy models were used to assess temporal trends in occupancy, detectability and vital rates of extinction and colonization for each species. Our results show significant declines in distribution for large carnivores, the Asian elephant and endemic ungulates and primates. There is a significant decline in detectability for 16 species, which suggests a decline in their abundance. These patterns of change in distribution and abundance repeat in our assessments of spatial variation in occupancy dynamics between the three contiguous forest complexes and two human-dominated landscapes into which the southern Western Ghats has been fragmented. Extinction rates are highest in the human-dominated landscapes. Declines in abundance for several species suggest the presence of extinction debts, which may soon be repaid with imminent range contractions and subsequent species extinctions unless immediate remedial conservation measures are taken. Detection/non-detection surveys of key informants used in an occupancy modeling framework provide potential for rapid conservation status assessments of multiple species across large spatial scales over time.  相似文献   

14.
Southeast Asia is one of the richest reservoirs of biodiversity on earth and home to one of the highest concentrations of endemic species. Many protected areas (PA) have been established across the region, but to date no systematic evaluation of their efficacy has been published because no comprehensive dataset was available which could be fed into an analysis of conservation gaps. We collected the geographic range for 1086 mammal species of Southeast Asia and we built species-specific habitat suitability models for 901 of them. We performed two gap analyses (one based on a combination of distribution models and distribution ranges and one based on distribution ranges only) for each mammalian species, to evaluate the effectiveness of the existing network of PA and to identify priority regions and priority species for expanding and consolidating the network. Our results indicate that 7.5-8.2% of species are not covered by any PA, and 51.6-59.1% are covered only partially. These species are distributed throughout the entire study area and their conservation requires the creation of new PA that can help fill this existing conservation gap. This would be particularly important for species which are endemic of small islands, where species survival is often threatened by the presence of introduced species and habitat conversion. Yet PAs cannot be considered as the ending point of a conservation strategy, because overall, 34% of the species we analyzed (many of which already covered by existing PAs) were at risk of extinction when considering the IUCN red-list criteria. PAs should therefore be considered in a broader framework of all local ecological and socio-economic trends, including the growing human population, growing economy and infrastructure development.  相似文献   

15.
For some groups such as bryophytes, the IUCN distribution criteria are of critical importance to evaluate threat status, since other parameters cannot be determined readily. In this study, we propose the use of ecological niche modelling methods to estimate the extent of occurrence (EOO) of species. Herbarium (LISU) collection data are used to estimate the potential distribution of bryophytes based on three different methods: GARP, MAXENT and ENFA. The records of bibliographic references were projected against model predictions, and used for validation purposes using the receiver operating characteristic (ROC) method, as well as knowledge about ecological and geographic affinities.Four species (Antitrichia californica, Riccia sommieri, Cryphaea heteromalla and Racomitrium hespericum) were chosen as case studies; they were selected to represent taxa with contrasting ecological requirements, biogeographic importance and conservation value. The main difference between the two approaches (topological and ecological) for determining EOO is that the former only consider species distribution in space, whereas ecological methods may include both spatial distribution as well as environmental ranges. The methodological advance presented here explores the links between population distribution and environmental data, filling the gaps between distribution and administrative borders.  相似文献   

16.
Hunting is one of the greatest conservation challenges facing tropical wildlife. Wildlife in Indian tropical forests are vulnerable to hunting, although data on hunting impacts from the region are limited. We use a meta-analysis of 143 hunting studies from India to identify the species and geographic regions most at risk, and to assess their legal protection. We found evidence of hunting in 114 mammal species, with larger-bodied mammals being particularly vulnerable. Although 75% of all studies focused on mammals, few actually quantified hunting impacts. Further, among studies of all terrestrial vertebrates where hunting was mentioned, only 6% focused exclusively on hunting. With further research, we expect that the suite of species known to be exploited by hunters will increase. We conclude that the Eastern Himalaya and Indo-Myanmar biodiversity-hotspot complex is particularly vulnerable to hunting. Quantitative studies of hunting impacts are urgently needed across India, especially in this biodiversity-hotspot complex.  相似文献   

17.
Understanding phyto-geographical distribution pattern and ethnobotanical applications are critical for comprehensive conservation and utilisation of native plant genetic resources. Dearth of such scientific reports on Corchorus species in India seriously compromises inclusiveness, precision and penetration of national endeavour to conserve the valuable resources. In this context, an ecogeographical study conducted to analyse geographical distribution, ecological adaptation, species richness and ethnobotanical applications of the genus in the country. The study revealed pandemic distribution of the genus with differential habitat preferences. Combine geographical, edaphic and precipitation based distribution profile of Corchorus spp. demonstrated multilayer interactions between species and environment that led to their differential spatial distribution. The highest species concentration was found in Tamil Nadu followed by Gujarat, Rajasthan, Madhya Pradesh and Maharashtra. Complementarity analysis showed that the major diversity hotspots for the genus present in Tamil Nadu and Gujarat. Besides, wide spectrum ethnobotanical applications of the genus reflect their long association with prevailing ethnic communities across regions. Documentation of such time honoured traditional practices has special bearing on designing comprehensive conservation and management strategies. This information will help to prioritise both ex-situ and in-situ conservation efforts for the genus particularly in ecologically vulnerable sites of India.  相似文献   

18.
In situ conservation of tropical forests often requires restricting human use and occupancy within protected areas by enforcing regulations. However, law enforcement interventions that seek to prevent deforestation rarely have been evaluated. Conservationists increasingly recognize the need to measure the effectiveness of their interventions, using an indicator of biodiversity change, such as rate of deforestation, and a counterfactual approach that addresses a fundamental question: what would have happened had there been no intervention? This study examines how law enforcement can mitigate habitat loss from small-holder coffee growing by comparing 34 years of empirical data on deforestation rates and coffee prices across a zone of high law enforcement and a zone of low law enforcement using satellite imagery, ecological data, interviews, and GIS modeling.In the early 1980s strong law enforcement efforts were found to reduce deforestation inside Bukit Barisan Selatan National Park (BBSNP), southwest Sumatra. However, law enforcement efforts were weak in remote areas of BBSNP, where high coffee prices spurred rapid deforestation. Furthermore, law enforcement efforts were reversed by the 1997-1998 Asian economic crisis, the fall of the national president, and by new regulations surrounding regional autonomy. These findings indicate that law enforcement is critical but insufficient alone. They also highlight that rising costs of agricultural commodities can be detrimental to tropical forests and their associated biodiversity. In the long run one must act to decrease the incentives for coffee cultivation. A multi-faceted strategy that includes law enforcement and incentives to reduce poverty around PAs is proposed.  相似文献   

19.
Presence-absence data are used widely in analysis of wildlife-habitat relationships. Failure to detect a species’ presence in an occupied habitat patch is a common sampling problem when the population size is small, individuals are difficult to sample, or sampling effort is limited. In this paper, the influence of non-detection of occurrence on parameter estimates of logistic regression models of wildlife-habitat relationships was assessed using analytical analysis and simulations. Two patterns of non-detection were investigated: (1) a random distribution of non-detection among occupied patches; and (2) a non-random distribution of non-detection in which the probability of detecting a species in an occupied patch covaried with measurable habitat variables. Our results showed that logistic regression models of wildlife-habitat relationships were sensitive to even low levels of non-detection in occupancy data. Both analytic and simulation studies show that non-detection yields bias in parameter estimation of logistic regression models. More importantly, the direction of bias was affected by the underlying pattern of non-detection and whether the habitat variable was positively or negatively related to occupancy. For a positive habitat coefficient, a random distribution of non-detection yielded negative bias in estimation, whereas linkage of the probability of non-detection to habitat covariates produced positive bias. For a negative habitat coefficient, the pattern was reversed, with a random distribution of non-detection leading to positive bias in estimation. A release-recapture livetrapping study of small mammals in central Indiana, USA, was used to illustrate the magnitude of non-detection in a typical field sampling protocol with varying levels of sampling intensity. Estimates of non-detection error ranged from 0 to 23% for seven species after 5 days of sampling. We suggest that for many sampling situations, relationships between probability of detection and habitat covariates need to be established to correctly interpret results of wildlife-habitat models.  相似文献   

20.
Freshwater ecosystems are among the most threatened in the world. In light of the threats to freshwater biodiversity, it is essential to map the distribution and status of species to ascertain their threat status for prioritizing conservation action. However, while there is agreement that the conservation of freshwater ecosystems depends on whole-catchment management, there are still a wide variety of large-scale mapping methods in use, the advantages and disadvantages of which have not been fully explored. This study shows that area estimation based on minimum convex polygons should not be encouraged for aquatic species. The IUCN definition of area of occupancy (AOO) is a useful term, albeit highly scale-dependent, for assessment of the total approximate area over which a species occurs. However, for aquatic fauna, and perhaps many other organisms, assessment of occurrence should be based on the more accurate point-locality presences only. The IUCN extent of occurrence (EOO), for freshwater catchment species, should be redefined as ‘the sum of the smallest hydrological units identified, of presently known, inferred or projected occurrences of a taxon, excluding cases of vagrancy, that are used to estimate the threat to a taxon’. A single hydrological unit is also the conservation or management unit. Here we suggest that this unit is the quaternary catchment. This new mapping approach is more appropriate and practical for use in both management planning and conservation action. We suggest that conservation managers and decision makers facilitate co-operation in freshwater mapping efforts by working at the same spatial scale, i.e. the same hydrological unit.  相似文献   

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