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51.
Bias toward legally protecting and prioritizing charismatic taxonomic groups, such as mammals and birds, and against others, such as insects and plants, is well documented. However, the relative costs of conserving various taxonomic groups and the potential of these costs to interact with existing biases have been much less explored. We analyzed conservation programs across more than 2,000 species in 3 countries to investigate the costs of conserving species within taxonomic groups and how these costs might affect conservation planning. For each data set, we tested for differences in mean annual cost among taxonomic groups. For the data set from the United States, recovery plans differed in duration, so we also tested for differences in total costs among taxonomic groups. Although the costs for individual species varied widely, there were strong international consistencies. For example, mammals cost 8–26 times more on average to conserve than plants and 13–19 times more to conserve than aquatic invertebrates. On average, bird species cost 5–30 times more to conserve than plants and 6–14 times more to conserve than aquatic invertebrates. These cost differences could exacerbate unequal resource allocation among taxonomic groups such that more charismatic groups both receive more attention and require more resources, leading to neglect of other taxonomic groups.  相似文献   
52.
G. W. Allison 《Marine Biology》1994,118(2):255-261
Patchy food distribution may force temporary starvation conditions on planktonic larvae. This potential food limitation may affect survivorship, duration of larval period, and post-metamorphic succes. In this study, larvae of the asteroid Asterina miniata were subjected to temporary food deprivation of several durations and at different stages. Developmental effects were documented by quantification of larval stage, total length, time to metamorphosis, initial juvenile radius, range of settling times, and percent survival to metamorphosis. All starved treatments were significantly affected in settling time and most in percent survival. However, larvae starved later in development demonstrated tremendous tolerance of food deprivation (e.g. the total number of settlers in the treatment starved for 28 d was not significantly different from the fed control). Survival was lower in treatments starved earlier in development than those starved later. Food is apparently required until late in larval development to facilitate metamorphosis. The range of settling times was large; for example, the continuously-fed control treatment produced juveniles from Days 58 through 136. Temporary starvation had no effect on initial juvenile radius.  相似文献   
53.
Habitat loss and fragmentation can negatively influence population persistence and biodiversity, but the effects can be mitigated if species successfully disperse between isolated habitat patches. Network models are the primary tool for quantifying landscape connectivity, yet in practice, an overly simplistic view of species dispersal is applied. These models often ignore individual variation in dispersal ability under the assumption that all individuals move the same fixed distance with equal probability. We developed a modeling approach to address this problem. We incorporated dispersal kernels into network models to determine how individual variation in dispersal alters understanding of landscape-level connectivity and implemented our approach on a fragmented grassland landscape in Minnesota. Ignoring dispersal variation consistently overestimated a population's robustness to local extinctions and underestimated its robustness to local habitat loss. Furthermore, a simplified view of dispersal underestimated the amount of habitat substructure for small populations but overestimated habitat substructure for large populations. Our results demonstrate that considering biologically realistic dispersal alters understanding of landscape connectivity in ecological theory and conservation practice.  相似文献   
54.
In 1990 the Environmental Protection Agency (EPA) began sponsoring several pilot projects in its regional offices to examine the potential benefits of adopting a multimedia approach to facility management. This approach differs from traditional practices at EPA in that facilities (dischargers regulated under permits issued by the agency) are managed based upon their cumulative impacts to all media: air, water, and land. Currently, facilities are managed by separate programs at EPA that evaluate environmental impacts from a single-media perspective. One aspect of discharger management is the necessity to allocate limited financial resources in a way that will minimize risk to human health and the environment. A careful, risk-based prioritization of facilities is one means of providing insight to the most effective strategy of allocating monitoring, inspection, and enforcement resources. Prioritization from a multimedia perspective is particularly difficult, however, since it requires translation and integration of medium-specific facility performances, management objectives, and perceptions of risk into a cumulative rating. A computerized decision support system (DSS) designed to guide management through the prioritization process from a multimedia perspective was identified as a potentially valuable tool for use in the pilot projects. This article describes the development of such a prototype, outlines the features of the completed system, and discusses its potential for use at EPA.  相似文献   
55.
When deciding how to conserve biodiversity, practitioners navigate diverse missions, sometimes conflicting approaches, and uncertain trade-offs. These choices are based not only on evidence, funders’ priorities, stakeholders’ interests, and policies, but also on practitioners’ personal experiences, backgrounds, and values. Calls for greater reflexivity—an individual or group's ability to examine themselves in relation to their actions and interactions with others—have appeared in the conservation science literature. But what role does reflexivity play in conservation practice? We explored how self-reflection can shape how individuals and groups conserve nature. To provide examples of reflexivity in conservation practice, we conducted a year-long series of workshop discussions and online exchanges. During these, we examined cases from the peer-reviewed and gray literature, our own experiences, and conversations with 10 experts. Reflexivity among practitioners spanned individual and collective levels and informal and formal settings. Reflexivity also encompassed diverse themes, including practitioners’ values, emotional struggles, social identities, training, cultural backgrounds, and experiences of success and failure. Reflexive processes also have limitations, dangers, and costs. Informal and institutionalized reflexivity requires allocation of limited time and resources, can be hard to put into practice, and alone cannot solve conservation challenges. Yet, when intentionally undertaken, reflexive processes might be integrated into adaptive management cycles at multiple points, helping conservation practitioners better reach their goals. Reflexivity could also play a more transformative role in conservation by motivating practitioners to reevaluate their goals and methods entirely. Reflexivity might help the conservation movement imagine and thus work toward a better world for wildlife, people, and the conservation sector itself.  相似文献   
56.
Behavioral Ecology and Sociobiology - Comparative analyses have demonstrated the existence of a ”pace-of-life” (POL) continuum of life-history strategies, from fast-reproducing...  相似文献   
57.
Phase II of the US Environmental Protection Agency's (USEPA) National Pollution Discharge Elimination System (NPDES) stormwater regulations requires communities smaller than 100 000 residents to meet new criteria for stormwater runoff reduction. In many cases these smaller communities have no established stormwater utility, and are investigating alternatives for complying with these new, sometimes expensive requirements. We note that it might be cost effective for some communities to encourage homeowners to control stormwater runoff at the parcel level instead of, or in conjunction with more traditional large, infrastructural best management practices (BMP). We go onto argue that in the absence of a strict regulatory cap, an auction is a cost-effective tool for implementing controls on stormwater runoff quantity at the parcel level. In this paper, we test the effectiveness of a procurement auction as the coordinating mechanism for encouraging installation of parcel-scale rain gardens and rain barrels within a small suburban watershed in the Midwest. The auction, which was conducted in spring 2007 and 2008, resulted in installation of 81 gardens and 165 barrels on 107 of the 350 eligible properties. Average cost per liter of runoff detention in both years was $0.36 for gardens and $0.59 for barrels. Interestingly, approximately 55% of the bids were for $0, suggesting that an educational campaign may result in substantial runoff mitigation if utilities paid for the installation of stormwater management practices. However, we found that an auction promoted more participation than education alone and at a cheaper per-unit control cost than a flat stormwater control payment plan. Overall, this study demonstrates that relatively minimal financial incentives can result in homeowners’ willingness-to-accept stormwater management practices on their property, thus opening an important avenue for retrofitting watersheds that are largely in private ownership.  相似文献   
58.

Introduction  

A greenhouse experiment was conducted to determine if Cucurbita pepo ssp. pepo (pumpkin) root exudates could increase the uptake of polychlorinated biphenyls (PCBs) into plants. Contaminated soil was pre-treated with pumpkin root exudates by first growing pumpkins in the soil. Plants (pumpkins and weeds) were grown in the pre-treated (root exudate group) and non-treated (control group) contaminated soils. Seeds from five weed species collected from two contaminated sites were germinated in sufficient quantities (n ≥ 6) for three seedlings to be planted in two groups.  相似文献   
59.
Estimates for the air releases of lead from stationary point sources are considered for the South Coast Air Basin of California. We have examined four databases published by U.S. Environmental Protection Agency, the California Air Resources Board, and the South Coast Air Quality Management District. Our analysis indicates that none of the databases includes every emitting facility in the South Coast Air Basin of California and that other discrepancies among the databases exist. Additionally, the data have been analyzed for temporal variation, and some of the California Air Resources Board data are not current. The South Coast Air Quality Management District inventory covers 12 times more facilities in 2001 than in 1996. From this analysis, we conclude that all four of the databases would benefit by sharing data, increasing transparency, analyzing uncertainty, and standardizing emission estimation methods.  相似文献   
60.
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