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311.
The expansion of protected areas is a critical component of strategies to promote the continued existence of biodiversity (i.e., life at all levels of biological organization) as climate changes, but scientific, social, and economic uncertainties associated with climate change are some of the major obstacles preventing such expansion. New models of climate change and species distribution and new methods of conservation planning now make it possible to explore the uncertainties associated with climate changes and species responses. Yet few reliable estimates of the costs of expanding protected areas and methods for determining these costs exist, largely because of the many (and uncertain) determinants of these costs. We developed a cost-accounting model to estimate the range in costs of various options for expanding protected areas and to explore the variables that drive these costs. Model development was informed by an existing plan to expand protected areas in the Cape Floristic Region of South Africa to address species conservation under a scenario of climate change. The 50-year present value of total costs varied from US$260 million ($1077/ha) for an off-reserve option that involves agreements with landowners and no compensation of forgone production and associated revenue to $1020 million ($4228/ha) for an on-reserve option that involves land acquisition and protection. The costs of acquiring land or compensating landowners for forgone production and development opportunities were the major drivers of the total costs across all options because most of the area identified in the protected-area expansion plan consisted of urban and high-quality agricultural lands. Total costs were also affected by changes in protected area extent and discount rate. Model-generated outputs such as these may be useful for informing implementation strategies and the allocation of future efforts in monitoring, data collection, and model development.  相似文献   
312.
Citizen science has the potential to expand the scope and scale of research in ecology and conservation, but many professional researchers remain skeptical of data produced by nonexperts. We devised an approach for producing accurate, reliable data from untrained, nonexpert volunteers. On the citizen science website www.snapshotserengeti.org , more than 28,000 volunteers classified 1.51 million images taken in a large‐scale camera‐trap survey in Serengeti National Park, Tanzania. Each image was circulated to, on average, 27 volunteers, and their classifications were aggregated using a simple plurality algorithm. We validated the aggregated answers against a data set of 3829 images verified by experts and calculated 3 certainty metrics—level of agreement among classifications (evenness), fraction of classifications supporting the aggregated answer (fraction support), and fraction of classifiers who reported “nothing here” for an image that was ultimately classified as containing an animal (fraction blank)—to measure confidence that an aggregated answer was correct. Overall, aggregated volunteer answers agreed with the expert‐verified data on 98% of images, but accuracy differed by species commonness such that rare species had higher rates of false positives and false negatives. Easily calculated analysis of variance and post‐hoc Tukey tests indicated that the certainty metrics were significant indicators of whether each image was correctly classified or classifiable. Thus, the certainty metrics can be used to identify images for expert review. Bootstrapping analyses further indicated that 90% of images were correctly classified with just 5 volunteers per image. Species classifications based on the plurality vote of multiple citizen scientists can provide a reliable foundation for large‐scale monitoring of African wildlife.  相似文献   
313.
New Zealand sea lions (Phocarctos hookeri) are threatened by incidental bycatch in the trawl fishery for southern arrow squid (Nototodarus sloanii). An overlap between the fishery and foraging sea lions has previously been interpreted as one piece of evidence supporting resource competition for squid. However, there is currently no consensus about the importance of squid in the diet of New Zealand sea lions. Therefore, we investigated this importance independently of spatial and temporal differences in squid availability through a simultaneous study with sympatric New Zealand fur seals (Arctocephalus forsteri), a species known to target arrow squid. Diet sampling at The Snares (48°01′S 166°32′E), subantarctic New Zealand, in February 2012 coincided with peak annual catch in the nearby squid fishery. Diets were deduced by analyses of diagnostic prey remains from scats (faeces) and casts (regurgitations). The contribution of each prey species to the diet was quantified using the per cent index of relative importance (% IRI) that combined frequency of occurrence, mass and number of prey items. Arrow squid was a minor component in sea lion scats (2 % IRI), and none was found in their casts. In contrast, arrow squid was the major component in fur seal scats and casts (93 and 99 % IRI, respectively). This study found that New Zealand sea lions ate minimal squid at a time when squid was clearly available as evidenced by the diet of New Zealand fur seals; hence, there was no indication of resource competition between sea lions and the squid fishery.  相似文献   
314.
How central-place foragers change search strategy in response to environmental conditions is poorly known. Foragers may vary the total distance travelled and how far they range from the central place in response to variation in the distribution of their prey. One potential reason as to why they would extend the length of their foraging trip and its distance from the colony would be to increase prey quality or quantity, despite incurring higher transit costs. To test this trade-off hypothesis in a species with high flight costs, we recorded the foraging behaviour of razorbills (Alca torca) using state-of-the-art techniques that log both individual horizontal (flight activity) and vertical (dive activity) movements. We show that the distance that razorbills travelled to foraging locations increased with sea-surface temperature, which may relate to higher prey quality or quantity. This relation is supported by an indirect index of patch quality, based on dive profiles, which also increased with travel distance from the colony. Furthermore, we show that this index was highest during the daily peak in diving activity, around midday. Taken together, these results suggest that razorbills are capable of adjusting their search strategies sensitively in response to proximate environmental cues.  相似文献   
315.
We reconstructed the history of Chatthin Wildlife Sanctuary (CWS) to understand how social and economic events, and policy changes affected the sanctuary's condition. We surveyed 25 villages surrounding CWS to evaluate past and present ecological conditions, compare the results with historical accounts and identify causal relationships. During the first half of the 20th century, the primary threat was the government's reduction of old growth forest to supply fuel wood for the British-built railway. The railroad opened the area to colonization, but the villagers' impact on timber and wildlife was low. From 1945 to 1988, villagers became the primary force of landscape degradation. The post-war windfall of firearms increased hunting pressure, and populations of large mammal started to decline. With the economic decline of the 1970s and 1980s, the community's demand for game and forest products intensified, and the large mammal fauna was reduced from eleven to four species. From 1988-2003, the forests surrounding the sanctuary were fragmented and degraded. The absence of large predators rendered the park safe for livestock, and the combined effects of grazing and removal of forest products seriously degraded habitat within CWS. Major threats to CWS during the past two decades have resulted from land use decisions in which government-planned economic enterprises caused encroachment by villagers. Stabilization and recovery of this sanctuary will require management compatible with human needs, including expanded buffer zones, better core area protection, community forestry projects, and probably relocation of villages within the park.  相似文献   
316.
A wildland fire is a serious threat for forest ecosystems in Southern Europe affecting severely and irreversibly regions of significant ecological value as well as human communities. To support decision makers during large-scale forest fire incidents, a multidisciplinary system has been developed that provides rational and quantitative information based on the site-specific circumstances and the possible consequences. The systems architecture consists of several distinct supplementary modules of near real-time satellite monitoring and fire forecast using an integrated framework of satellite Remote Sensing, GIS, and RDBMS technologies equipped with interactive communication capabilities. The system may handle multiple fire ignitions and support decisions regarding dispatching of utilities, equipment, and personnel that would appropriately attack the fire front. The operational system was developed for the region of Penteli Mountain in Attika, Greece, one of the mountain areas in the country most hit by fires. Starting from a real fire incident in August 2000, a scenario is presented to illustrate the effectiveness of the proposed approach.  相似文献   
317.
Conservation planning is the process of locating and designing conservation areas to promote the persistence of biodiversity in situ. To do this, conservation areas must be able to mitigate at least some of the proximate threats to biodiversity. Information on threatening processes and the relative vulnerability of areas and natural features to these processes is therefore crucial for effective conservation planning. However, measuring and incorporating vulnerability into conservation planning have been problematic. We develop a conceptual framework of the role of vulnerability assessments in conservation planning and propose a definition of vulnerability that incorporates three dimensions: exposure, intensity, and impact. We review and categorize methods for assessing the vulnerability of areas and the features they contain and identify the relative strengths and weaknesses of each broad approach. Our review highlights the need for further development and evaluation of approaches to assess vulnerability and for comparisons of their relative effectiveness.  相似文献   
318.
ABSTRACT: With the recent increased exploration and mining activity in the Northwest Territories, there has been growing interest in streamflows. However, streamflow monitoring in Canada's north is limited, especially in the central Northwest Territories where the exploration activity is concentrated. To complicate matters, the standard approach of measuring discharge with current meters or weirs is often inadequate or prohibitively expensive, as many streams in the region are shallow, braided and rocky. In response, alternative techniques such as salt dilution can be used. A salt tracer's competence in turbulent and rocky channels makes it ideal for discharge measurements in these situations. This paper summarizes the work performed by Indian and Northern Affairs Canada and Canamera Geological Ltd. staff in determining the stream discharge of a lake outlet using a potassium chloride (KC1) tracer. A variety of streamflow measurement methods were performed and compared to determine the viability and rigor of the dilution method. Results suggest the dilution method compares favorably to other measurement techniques both in accuracy and operational ease.  相似文献   
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