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Few studies have investigated the factors that influence roadkill occurrence in developing countries. In 2013, we monitored a 100‐km section of the road (comprising the R572 and R521 regional highways and the D2662) that pass through the Greater Mapungubwe Transfrontier Conservation Area in South Africa, to assess the possible factors influencing roadkill. Over a period of 120 days, and across the three ecological seasons, we recorded 981 roadkills (rate = 0.08 roadkill/km/day) from four vertebrate taxonomic groups. We generated predictive models of roadkill from one combined data set that considered eight variables identified from the literature as potential correlates of roadkill. The model that included the distance of the fence from the road, habitat type adjacent to the road, and the presence of a hill in the road (i.e., elevation) or a bank on the side of the road best explained roadkill occurrence. More roadkill was predicted to occur in both open and dense mopane and dense mixed bushveld habitats, on a hill, when there was a bank on the side of the road, and as the distance between the road verge and a fence decreased. Our model provides some insight into the significant predictors of roadkill occurrence and is therefore a valuable tool in identifying sites of high‐potential roadkill frequency and formulating mitigation measures for reducing road mortalities.  相似文献   

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A community-based monitoring system that focuses on natural resource use and forest quality in montane evergreen forest and miombo woodland areas was developed and implemented in 23 villages in 2002 as part of a participatory forest management regime in Iringa District, Tanzania. The scheme was developed to suit the needs and capacities of locally-elected natural resource committees managing and monitoring natural forests. Rather than measuring biodiversity, the monitoring is focused on resource extraction and disturbance. High levels of commitment to the monitoring were displayed by village level managers, and the preliminary feed-back indicates that the monitoring scheme provides them with the relevant information needed to suggest appropriate management interventions. While external support has been essential to cover development costs, natural resource revenue generated at village level can provide most of the running costs. Once developed, the scheme can, however, be transferred to similar areas at significantly lower costs that can be met by Tanzanian District budgets. Natural resource revenue generated from montane forests is generally much lower than in woodland areas due to restrictions on resource extraction imposed as a consequence of national and international interests. Opportunities to provide economic incentives for montane forest managers through direct utilisation of the resource are limited and it remains to be seen whether other non-economic incentives can sustain long term commitment in these biodiversity rich areas. Findings indicate that the key elements of this local resource utilisation monitoring scheme are simplicity, incentive mechanisms, transparency and accountability, and autonomy for local managers. However, the methods may not provide sufficient data on changes in biodiversity values in the high value forests and may need to be augmented by conventional monitoring by scientists funded by national or international institutions. Elements of the scheme are now being institutionalised within the forestry sector in Tanzania.  相似文献   

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Plant resources are used, managed and conserved by local communities in many parts of the world. However, very few studies have examined the site-specific factors and mechanisms that affect resource extraction. We apply methodology from the social and biological sciences to examine the cultural and socio-economic factors that influence the harvest practice and resource use of indigenous wood carvers in the Maningrida region of central Arnhem Land. Woodcarvers from this region use a small number of carving timbers with two species dominant, Bombax ceiba and Brachychiton diversifolius. There were many cultural differences in harvest practice, with artists from the Kuninjku/Kunibeidji language community harvesting a greater number of tree species, larger quantities per harvest trip and smaller sized stems. Socio-economic factors also played an important role in facilitating the collection of stems as artists owning a vehicle acquired more stems than those who did not. Harvest sites closest to the township of Maningrida had higher visitation frequencies than those further away. These influences on harvest practice have significant implications for the ecological sustainability of timber harvesting in this region and we highlight the need to examine such localised factors when assessing the sustainability of indigenous wildlife harvests.  相似文献   

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Angels on a Pin: Dimensions of the Crisis in Invertebrate Conservation   总被引:1,自引:0,他引:1  
Problems of measuring invertebrate diversity in natural communitiesare discussed, together with the rationale of setting prioritiesfor effective conservation of invertebrates. The "Crisis" ininvertebrate conservation has scientific, logistic, and ethicaldimensions. There is need to estimate these in conjunction witha range of values and educational imperatives to overcome publicprejudice against invertebrates and to increase conservationfunding for invertebrates. Values for selecting priority groupsare discussed, and a suite of priority taxa defined to maximisethe conservation value of the limited resources available.  相似文献   

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Approaches to the management of protected areas that involve the participation of local communities are now being widely promoted. However, the impacts of such community-based conservation initiatives on local communities remain poorly defined. This research examines the socio-economic impacts of community-based conservation within the Annapurna Conservation Area (ACA), Nepal, through semi-structured interviews and a questionnaire survey with local residents, situated both within and outside the protected area. Results indicate that local communities have received a number of benefits from conservation, including improvements in access to forest resources, improved basic infrastructure such as drinking water, trails and bridges, and improvements in health, sanitation and social services. However, relatively few people (14.9%) within ACA receive direct financial income from tourism. Local communities also experience a number of costs of being involved in conservation, the most significant of which is increased crop damage by wildlife. Eighty-four percent of respondents within ACA have experienced problems of crop damage, accounting for 6% (rice) to 23% (maize) of total production. Depredation of livestock by wildlife is also experienced; mean losses per household being the equivalent of £3.9 (Rs. 479.70) each year. However, 66% of respondents within ACA reported that they had never experienced this problem. These results indicate that the socio-economic benefits of community-based approaches to conservation can outweigh the costs, even though the latter are significant. However, a participatory approach to management of problematic animal species will need to be developed within ACA, if conflicts between local communities and protected area management are to be avoided in future.  相似文献   

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通过"贵州农业生物资源调查"项目的调查,获得了大批农业生物种质资源,这些种质资源具有丰富的物种多样性和遗传多样性,它们是贵州少数民族世代相传的物质遗产,也是贵州少数民族生活和生产的物质基础。与此同时,通过调查说明,贵州少数民族地区农业生物资源还有很大的调查收集潜力。由此不难看出,有效保护和可持续利用贵州农业生物资源,不论对贵州还是对中国都具有重要的现实和长远意义。  相似文献   

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A striking contrast runs through the last 60 years of biopharmaceutical discovery, research, and development. Huge scientific and technological gains should have increased the quality of academic science and raised industrial R&D efficiency. However, academia faces a "reproducibility crisis"; inflation-adjusted industrial R&D costs per novel drug increased nearly 100 fold between 1950 and 2010; and drugs are more likely to fail in clinical development today than in the 1970s. The contrast is explicable only if powerful headwinds reversed the gains and/or if many "gains" have proved illusory. However, discussions of reproducibility and R&D productivity rarely address this point explicitly. The main objectives of the primary research in this paper are: (a) to provide quantitatively and historically plausible explanations of the contrast; and (b) identify factors to which R&D efficiency is sensitive. We present a quantitative decision-theoretic model of the R&D process. The model represents therapeutic candidates (e.g., putative drug targets, molecules in a screening library, etc.) within a “measurement space", with candidates'' positions determined by their performance on a variety of assays (e.g., binding affinity, toxicity, in vivo efficacy, etc.) whose results correlate to a greater or lesser degree. We apply decision rules to segment the space, and assess the probability of correct R&D decisions. We find that when searching for rare positives (e.g., candidates that will successfully complete clinical development), changes in the predictive validity of screening and disease models that many people working in drug discovery would regard as small and/or unknowable (i.e., an 0.1 absolute change in correlation coefficient between model output and clinical outcomes in man) can offset large (e.g., 10 fold, even 100 fold) changes in models’ brute-force efficiency. We also show how validity and reproducibility correlate across a population of simulated screening and disease models. We hypothesize that screening and disease models with high predictive validity are more likely to yield good answers and good treatments, so tend to render themselves and their diseases academically and commercially redundant. Perhaps there has also been too much enthusiasm for reductionist molecular models which have insufficient predictive validity. Thus we hypothesize that the average predictive validity of the stock of academically and industrially "interesting" screening and disease models has declined over time, with even small falls able to offset large gains in scientific knowledge and brute-force efficiency. The rate of creation of valid screening and disease models may be the major constraint on R&D productivity.  相似文献   

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In social insects, selection takes place primarily at the level of the colony. Therefore, unlike solitary insects, social species are expected to forage at rates that maximize colony fitness rather than individual fitness. Workers can increase the net benefit of foraging by responding to increased resource availability, by responding more strongly to higher‐quality resources, and by decreasing the uncertainty with which nestmates find resources. Unlike many ants and social bees, no social wasp is known to utilize a nest‐based recruitment signal to inform nestmates of food location. On the other hand, wasps do learn the odor of food brought to the nest and use this cue to locate the food source outside the nest. Here, we quantify the effects of three food‐associated variables on the allocation of foraging effort in the yellowjacket Vespula germanica. We used an experimental approach to assess whether resource quantity, quality, or associated olfactory information affect the probability that a forager will leave the nest on a foraging trip. We addressed these questions by inserting a known amount of sucrose solution directly into nests and recording foraging effort (departure rate) over the subsequent hour‐long observation period. No differences were found in foraging effort because of the presence/absence of olfactory cues, but there was strong evidence that foraging effort increased in response to resource influx and resource quality. Thus, while olfactory cues are learned in the nest, only resource quality and the cue of increased amount of food in the nest factor into a forager's decision of whether or not to depart on a foraging trip. However, as prior work has shown, once a wasp forager leaves the nest, it uses the learned olfactory cues to aid in finding resources.  相似文献   

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The mainstream view in natural resource management in African drylands has been that local people are responsible for natural resource degradation. Today, alternative views or new paradigms are emerging in several fields. These new paradigms, which support decentralization of natural resource management, are discussed in relation to the ongoing decentralization process in Mali. During the colonial period, heavily centralized governments were installed in all the French colonies. This structure was maintained by Malian governments after independence. However, following the recent transition to democracy, a decentralizing reform is being implemented. It is presently not clear whether these reforms will lead to mere deconcentration, involving the redistribution of administrative responsibilities within the central government, or whether Mali is heading toward real decentralization, devolving decision making powers to local communities. The gestion de terroir approach, which may be a useful tool in achieving decentralization in farming communities, would, in pastoral areas, cause more damage than benefit.  相似文献   

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This study focuses on knowledge of medicinal plants among the Caiçaras (rural inhabitants of the Atlantic Forest coast, Brazil). In particular, we examine the use of medicinal plants according to sex and age to reveal general patterns of Caiçara knowledge and use of plant resources. Data collected through 449 interviews at 12 Caiçara communities (Rio de Janeiro and São Paulo coastal sites) include citations of 249 plants and identification of 227 species. We show the importance of introduced as opposed to native plants and of key individuals for the conservation of the Caiçaras-Atlantic Forest.  相似文献   

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Throughout the short history of industrial ecology, issues of implementation have been heavily emphasized. Less attention has been given to the ways in which the technical models of industrial ecology interact with social processes. Yet the practitioners of industrial ecology frequently encounter challenges pertaining to contextualization when embedding a general model in different local contexts. In addition, there are reasons to believe that the models of industrial ecological systems become politically meaningful only when they are carefully contextualized and linked to localized needs. In this article, we aim at a better understanding of the political embedding of industrial ecology. In order to demonstrate some general mechanisms of embedding, we first conduct a frame analysis of complex utilization—a scientific policy instrument analogous to industrial ecology, developed in the Kola Peninsula, Russia. We identify five frames in which complex utilization has been promoted between 1935 and 2005. These frames are then compared to six frames identified in the industrial symbiosis in Kalundborg, Denmark. We find that effective political embedding relies on frames that function both on a general level and in specific contexts. General frames, such as efficiency, economy, and environment, need to be aligned with localized perceptions of particular issues. What is more, sensitivity to purely context-specific frames is necessary for effective political embedding. Finally, the political processes of framing also shape the scientific-technical models that are being promoted.  相似文献   

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报道并探讨了河北省在大鸨迁徙途径中的重要性,河北省大鸨的地理分布与居留期变化,大鸨的保护工作及其保护与研究展望,指出河北省是大鸨重要的越冬地.  相似文献   

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The Gahai Lake wetland natural conservation area in northwestern China includes peatland that has been accumulating over hundreds of years and is seldom disturbed by industry. Bacteria and archaea in peat soil, which is a reservoir for carbon and water, may influence its ecological function. The objective of this study was to obtain a clearer understanding of peat microbial ecology and its relationship to the environmental conditions of this area. Hence, the microbial community of the peatland ecosystem was investigated by sequencing bacterial and archaeal DNA extracted from samples collected at different peat depths. Results showed that in all samples the dominant bacterial phyla were Proteobacteria (relative abundance 0.39 ± 0.12) and Chloroflexi (0.16 ± 0.09), while the dominant archaeal phyla were Miscellaneous Crenarchaeotic Group (MCG) (0.62 ± 0.21) and Euryarchaeota (0.27 ± 0.16). The diversity and microbial community structure at deeper depths (90 and 120 cm below the peat surface) significantly differ from that at shallower depths (10, 30 and 50 cm deep). In contrast to the shallow layers, the deeper layers became more abundant in the bacterial phyla Chloroflexi, Bacteroidetes, Atribacteria, Aminicenantes, Chlorobi, TA06, Caldiserica and Spirochaetae; and in the archaeal phyla MCG and Miscellaneous Euryarchaeotic Group (MEG). This study revealed a significant shift in microbial community in peat between 50 cm and 90 cm deep, as probably influenced by the oxygen supply at different depths. Furthermore, new insights into the microbial taxa were obtained, thus providing a baseline for future studies of this peat ecosystem.  相似文献   

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We examined the patterns of habitat use of six radio-tagged booted eagles (Hieraaetus pennatus) in a Special Protection Area (SPA) in southeastern Spain. Variable percentages of radio locations (20.8–72.0 %) and home range areas (45.2–81.3 %) lay outside the SPA limits. A model selection procedure showed that habitat use was mainly influenced by habitat type and the distance to the nest. Edges and open lands were the most selected habitat types at long distances, while the probability of forest use strongly decreased with the distance. We conclude that effective conservation strategies for this species should encourage not only the protection of the forest nesting habitats, but also the traditional agricultural practices of the surrounding agroecosystems.  相似文献   

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