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1.
Protected area managers have limited resources and so need fine-scale information to decide where to focus their budgets for law enforcement and community outreach. This study used satellite imagery to map and analyse forest loss in an area that overlaps with Kerinci Seblat National Park, Sumatra, to identify areas most susceptible to illegal logging. Between 1985 and 1992, forest located at lower elevation and close to roads was most vulnerable to clearance. These factors were also significant between 1992 and 1999, along with distance to newly created logging roads. The presence of these roads probably explained why the deforestation rate increased from 1.1% per year to 3.0% per year over the two study periods. The accuracy of the 1985–1992 model was measured in the field and successfully predicted subsequent deforestation patterns, suggesting that this methodology could be used to identify where future patrolling effort and community outreach programmes should be focussed. In addition, this approach could be used more widely in conservation planning to prioritise the protection of vulnerable sites.  相似文献   

2.
Abstract. A vegetation map at scale 1:5 million is presented. * * Attached on the inside of this issue's back cover.
It covers Bangladesh, Burma (Myanmar), India, Cambodia, Laos, Thailand, Vietnam and Sri Lanka and fills a conspicuous gap in the cartography of tropical vegetation, following the publication of vegetation maps of South America, Africa and Malaysia. For conformity, it is presented as one sheet at a scale of 1:5 million. It uses the basic map of the American Geographical Society (1942; bipolar oblique conformal projection) which forms the base for FAO's Soil map of the world. Basic information was obtained from many published maps, unpublished observations and satellite data. The limits of the main vegetation types have been updated with a complete set of Landsat MSS images (369 scenes) with a mosaic of Landsat TM data for 1991 and with recent forest maps from Asia. Nine main vegetation units, which are groups of forest formations, have been identified and mapped, including woodlands, thickets and wooded savannas. Agricultural land has been shown in a uniform pale green colour in order to clearly express the extent of human impacts on woody vegetation. In spite of the necessary oversimplification of the ground data, this map is probably the most explicit expression of the remaining forest stands and of the regression of natural vegetation in the region. It can be considered as a benchmark for future monitoring of tropical vegetation.  相似文献   

3.
In Iran, mangroves are located in the south of the country, where they fulfill essential ecosystem functions, but some parts of them have been destroyed for various reasons in recent years so that it seems necessary to have a management plan consistent with the conservation of this ecosystem. But, it needs knowledge of the trend of and reasons for the degradation of these forests. So, the primary idea of this research was to discover the factors involved in the degradation of these forests and how to manage them. So, the research first used the remote sensing technique to determine the rate of their degradation over the last 20 years. Then, using the Delphi technique, 45 factors were identified for the degradation of these forests and they were classified into five categories including climatic and environmental, anthropogenic, socioeconomic, psychological, and policymaking and legal. Finally, the analytic hierarchy process (AHP) was used to rank these factors within two management paradigms of remediability and preventability so that the ecosystem can be soundly managed by classifying these factors. Overall, the results can provide policymakers with new insights into forest management and the policies presented here can contribute to the sustainability of this ecosystem.  相似文献   

4.
Poverty and environmental degradation seem to be endemic in many of the former homeland territories of South Africa. The political legacy of Apartheid might have ceased, but the economic and environmental consequences thereof still have to be dealt with. In one interesting case such a poverty-stricken and environmentally degraded area (Bushbuckridge) lies adjacent to a world conservation icon, the Kruger National Park. Currently, however, the community of Bushbuckridge does not enjoy much benefit from this unique geographic location. On the contrary there seems to be increasing tension between the community in their quest for survival and the national park as a conservation enclave. This tension will not disappear automatically. The situation needs to be managed. It is proposed here that by broadening the conservation corridor through land restoration and by incorporating the Bushbuckridge communal land as an IUCN Category VI protected area (a protected area within which sustainable resource harvesting by communities is permitted) into the Kruger National Park and under the provision that the community remains the land owner, the conservation initiative could benefit the community as much as by a factor of four. For this to be successful a proper managerial and institutional system will have to be in place, including a system that will allow the trade in ecosystem goods and services.  相似文献   

5.
Due to differences in the responses of species to changing landscape patterns, developing a conservation plan with an optimal outcome of supporting contrasting habitat needs can be difficult. Landscape scenario modeling can provide a means to compare alternative conservation strategies and can reveal tradeoffs of managing for one objective versus another. In order to evaluate the impacts of alternative conservation strategies in a 53,653 ha landscape in Michigan's Upper Peninsula, four scenarios of alternative conservation strategies were modeled 100 years into the future using the VDDT®/TELSA® spatial model suite, and habitat availability was evaluated for five target bird species of local conservation concern under each scenario. The target species were Dendroica fusca (Blackburnian Warbler), Picoides arcticus (Black-backed Woodpecker), Dendroica kirtlandii (Kirtland's Warbler), Buteo lineatus (Red-shouldered Hawk), and Scolopax minor (American Woodcock). Scenarios were ranked based on relative performance of three habitat metric results (total primary habitat area, average size of habitat patches, and average distance to the nearest neighboring habitat patch) for each species. The final overall rank for each scenario was generally related to harvest intensity; the scenario with the smallest total area of even-aged management ranked the highest. Ranks were not consistent across all response variables. Relative species sensitivity was also evaluated, and the ranks did not match expectations, with the more habitat generalist species showing the highest sensitivity and the most specialist species showing the lowest. The approach here provides a means of projecting and comparing potential long-term impacts of alternative landscape strategies on diverse wildlife habitats. These results, when considered with budget considerations and species’ habitat area and population goals, can assist local managers and stakeholders in conservation planning by identifying tradeoffs and compromises aimed at optimizing protection for a variety of target species.  相似文献   

6.
Question: Is the successional transition from pine to hardwood, which has been inferred from chronosequence plots in previous studies, validated through a time line of satellite imagery? Location: Durham, North Carolina, USA. Methods: We examined successional trends in a time‐series of winter‐summer pairs of Thematic Mapper imagery from 1986 to 2000. We calculated the normalized difference of vegetation index (NDVI) for winter and summer, as well as the difference between summer and winter NDVI (i.e., summer increment NDVI). A set of approximately 50 forest stands of known age and phenology were used to interpret patterns in winter and summer increment NDVI over successional time, and a continuum was found to exist between pine‐dominance and hardwood‐dominance. We fitted a series of linear regressions that modeled the change in winter and summer increment NDVI as a function of initial winter and summer increment NDVI, and additional explanatory variables. Results: All regressions were highly significant (P < 0.0001, R2= ca. 0.3). Predicted dynamics are in accord with successional theory, with pixels moving from evergreen dominance to deciduous dominance along a line of fairly constant summer NDVI. A large disturbance event that occurred over the course of this study, Hurricane Fran, appeared to slow rates of succession in the short term (1–3 years), but increase the rate of conversion to hardwoods over longer time spans. Conclusions: We conclude that temporal sequences of remote sensing images provide an excellent opportunity for broad‐scale monitoring of successional processes, and that continuous metrics of that change are essential to accurate monitoring.  相似文献   

7.
Abstract

A Red List of all 108 Pezizomycotina (Ascomycota) species recorded in Umbria Region (central Italy) is provided. According to the IUCN categories and criteria, 60.18% of the assessed species are classified as threatened, whereas 12.96% are Near Threatened (NT), 1.86% are Least Concerned (LC) and a noteworthy amount of 25% are Data Deficient (DD). As a consequence of the downlisting applied to the majority of the assessed taxa, according to the guidelines for application of IUCN red list criteria at Regional level, only 1.54% of the threatened species is Critically Endangered (CR), while 46.15% are Endangered (EN) and 52.31% are Vulnerable (VU). Given that the present work represents the first complete regional red list of Pezizomycotina in Italy, and that a national, as well as a European red list do not exist to date, it could be considered as a case study for other Italian Regions as well as for other European countries, aiming at the compilation of a national and European red list of this fungal group mostly overlooked in conservation strategies.  相似文献   

8.
We studied the colonisation rate of insects inhabiting fruiting bodies of the wood-decaying fungus Fomitopsis pinicola both within and at different distances (up to 1610 m) from an old-growth forest reserve. The colonisation rate of most species was not affected by the distance from the reserve, and none of the species were affected by the size of local sources of fruiting bodies in the managed forest. We suggest that many insect species inhabiting fruiting bodies of wood-decaying fungi can colonise fruiting bodies at a high enough rate to persist in managed forests of Fennoscandia. However, the colonisation rates of the fungivorous beetle Cis quadridens and the predatory fly Medetera apicalis were negatively affected by distance from the reserve. Cis quadridens is rare in many managed forests, but often quite common at sites with high substrate densities. The rarity of this species may therefore be due to weak ability to colonize distant patches. The same may also be true for M. apicalis, but less is known about the biology of this species. Medetera apicalis was the most common insect predator in the old-growth forest, but it was rare at the largest distances from it in the managed forest. Therefore, it seems likely that the overall pressure from natural enemies significantly declined with distance from the reserve.  相似文献   

9.
The elastic laminae were extracted from thoracic aortas of adult animals including sheep, dogs, rabbits, cats and rats by treating them in hot alkaline solution (0.1 N NaOH at 75 degrees C) and observed with a scanning electron microscope. The elastic laminae are comprised of sheet-like internal elastic lamina, fibrous and membraneous elastin in tunica media, interlamellar fibers and hollow spaces which we presume were formerly filled with smooth muscle cells in the tunica media. These structures are the same in all five species except that the number of layers and the total thickness of the wall differs.  相似文献   

10.
Although the aim of conservation planning is the persistence of biodiversity, current methods trade-off ecological realism at a species level in favour of including multiple species and landscape features. For conservation planning to be relevant, the impact of landscape configuration on population processes and the viability of species needs to be considered. We present a novel method for selecting reserve systems that maximize persistence across multiple species, subject to a conservation budget. We use a spatially explicit metapopulation model to estimate extinction risk, a function of the ecology of the species and the amount, quality and configuration of habitat. We compare our new method with more traditional, area-based reserve selection methods, using a ten-species case study, and find that the expected loss of species is reduced 20-fold. Unlike previous methods, we avoid designating arbitrary weightings between reserve size and configuration; rather, our method is based on population processes and is grounded in ecological theory.  相似文献   

11.
Stenocereus quevedonis (‘pitire’) is a columnar cactus endemic to central Mexico, grown for its edible fruit. Phenology, pollination biology and behaviour of flower visitors of this species were compared in six conserved and disturbed sites, hypothesising that: (i) pitire pollination is self‐incompatible, requiring animal vectors; (ii) higher incidence of radiation on plants in cleared forest may lead to a higher number of flowers per pitire plant and longer blooming season, and disturbing and differential spatial availability of flower resources may determine differential attraction of pollinators to conserved and disturbed areas; (iii) if pitire pollination system is specialised, reproductive success would decrease with pollinator scarcity, or other species may substitute for main pollinators. In all sites, pitire reproduction started in January, flowering peak occurring in April, anthesis duration was 15 h and predominantly nocturnal (9 h), pollen was released at 23:00 h, nectar was produced throughout anthesis, and breeding system was self‐incompatible. Flower production per plant was similar in disturbed and conserved sites, but flower availability was higher (because of higher tree density) and longer in disturbed sites. Pollination is nocturnal, the most frequent legitimate pollinator being the bat Leptonycteris yerbabuenae; diurnal pollination is rare but possible, carried out by bee species. Fruit and seed set in control and nocturnal pollination treatments at disturbed sites were higher than in conserved sites. Frequency of L. yerbabuenae visits was similar among site types, but more visits of complementary nocturnal and diurnal pollinators were recorded in disturbed sites, which could explain differences in reproductive success.  相似文献   

12.
The Brazilian Atlantic Forest biome is considered a hotspot of biodiversity. It is estimated that today the remaining primary vegetation covers only 7.5% of its original area. Bromeliad species are important components of this biome. Some of these species are endemic, like the highly endangered Vriesea reitzii. Tissue culture techniques have been often employed for the mass propagation and conservation of threatened bromeliad species. In the present work we describe a procedure for the micropropagation and in vitro conservation of V. reitzii. Seedling explants were cultured on MS and LPm liquid media supplemented with BA, NAA and GA3. The induction and multiplication of shoots were observed in the MS medium supplemented with NAA (2 μM) and BA (4 μM). The best conditions for maintenance and conservation of shoots were half-strength or MS medium. Shoot elongation was observed in MS medium supplemented with GA3 (10 μM). MS medium supplemented with NAA (1 μM) and BA (2 μM) enabled an efficient proliferation system. The acclimatization of shoots longer than 2 cm resulted in 100% survival rate.  相似文献   

13.
For more than 30 years, the US National Science Foundation's Research Experiences for Undergraduates (REU) program has supported thousands of undergraduate researchers annually and provides many students with their first research experiences in field ecology or evolution. REUs embed students in scientific communities where they apprentice with experienced researchers, build networks with their peers, and help students understand research cultures and how to work within them. REUs are thought to provide formative experiences for developing researchers that differ from experiences in a college classrooms, laboratories, or field trips. REU assessments have improved through time but they are largely ungrounded in educational theory. Thus, evaluation of long‐term impacts of REUs remains limited and best practices for using REUs to enhance student learning are repeatedly re‐invented. We describe how one sociocultural learning framework, cultural–historical activity theory (CHAT), could be used to guide data collection to characterize the effects of REU programs on participant's learning in an educationally meaningful context. CHAT embodies a systems approach to assessment that accounts for social and cultural factors that influence learning. We illustrate how CHAT has guided assessment of the Harvard Forest Summer Research Program in Ecology (HF‐SRPE), one of the longest‐running REU sites in the United States. Characterizing HF‐SRPE using CHAT helped formalize thoughts and language for the program evaluation, reflect on potential barriers to success, identify assessment priorities, and revealed important oversights in data collection.  相似文献   

14.
 The mycorrhizal status of Astragalus applegatei Peck is reported for the first time on plants from a greenhouse soil bioassay. Seedlings were grown in a potting mix inoculated with soil collected near A. applegatei plants in nature. Plants were also grown in non-inoculated potting mix. Only plants from the native soil inoculation survived. Abundant colonization of VAM fungi was found in all 15 plants analyzed from the native soil treatment, and chlamydospores produced by Glomus spp. were observed. Mycorrhizal colonization was estimated to be 23% of total fine root length after 6 weeks and 53% after 14 weeks. Our results provide ecologically important information for conservation and restoration efforts underway to recover populations of this endangered species. Accepted: 22 June 1998  相似文献   

15.
16.
We assessed how environmental drivers influence the occurrences of wood-inhabiting macrofungi in European beech forests, using an extensive dataset of fruit body records collected in 53 reserves across twelve European countries. We found that the 105 species included in this study varied greatly in their responses to covariates related to resource quality, climate and forest connectivity, both in the strength and direction of the observed effects. Climate was the most important driver for some species, while others responded more to connectivity, or simply to the presence of high quality substrates within the reserves. Species occurrences varied also across geographical regions, especially between the UK and the rest of Europe. Our results show that wood-inhabiting fungi in European beech forests respond individualistically to habitat filters and differ in their biogeographical distribution patterns, and they thus provide a detailed perspective of how wood-inhabiting fungal communities are structured across Europe.  相似文献   

17.
沿海地区森林风害研究综述   总被引:7,自引:0,他引:7  
从导致森林风害的因素、风害对沿海森林生态系统的影响、风害评估方法、降低森林风害的经营管理措施等方面,综述了风害与沿海森林生态系统关系的研究成果和不足。我国未来应加强在不同尺度下沿海森林结构与功能关系、局域和区域尺度下各类生物/非生物因素与森林风害的关系以及森林风害预测评估模型的构建等3方面的研究。  相似文献   

18.
Long-term ecological sites are 'listening places'– places where we press our ears to the earth and strain to hear its pulse. Such sites will be needed especially in coming decades, as ecosystems throughout the world face mounting stresses, mostly from human influences. My aim, in these musings, is to elicit conversation, by way of seven questions, about how best to look after the long-term sites, so that they remain intact, relevant, and enlightening for our successors, decades hence.  相似文献   

19.
CRESPO, MB., 1992. A new species of Vella L. (Brassicaceae) from the south-eastern part of the Iberian Peninsula . Vella lucenlina is described from the coastal, low, dry areas of Alicante Province (south-eastern Spain). This plant is a spineless shrub, woody at the base, with narrowly linear, entire leaves, and an acute tongue-shaped stylar part of the fruit. Affinities and differences with the other taxa in the genus are discussed, and ecological data and conservation proposals are reported.  相似文献   

20.
The dwarf sawfish, Pristis clavata, was captured in marine waters of King Sound and estuarine waters of the Fitzroy, May and Robinson Rivers, in the Kimberley region of Western Australia. Observations of sexual maturity and annuli present on vertebrae suggest that the estuarine waters of at least the Fitzroy River act as a nursery for the species, where immature individuals may remain for at least 3 years. The capture of immature individuals in excess of 2,330 mm TL during the current study in addition to Peverell’s (Peverell in Environ Biol Fishes 73:391–402, 2005) record of a mature male measuring 3,060 mm TL implies that the species may attain far greater lengths than previously reported and that the common name may not be entirely appropriate. In contrast to the sympatric freshwater sawfish Pristis microdon, the number of rostral teeth of individual P. clavata can not be used to differentiate males from females, with both sexes possessing an average of 42 rostral teeth.  相似文献   

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