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排序方式: 共有381条查询结果,搜索用时 140 毫秒
241.
Matt W. Hayward Alex Callen Benjamin L. Allen Guy Ballard Femke Broekhuis Cassandra Bugir Rohan H. Clarke John Clulow Simon Clulow Jennifer C. Daltry Harriet T. Davies-Mostert Peter J. S. Fleming Andrea S. Griffin Lachlan G. Howell Graham I. H. Kerley Kaya Klop-Toker Sarah Legge Tom Major Ninon Meyer Robert A. Montgomery Katherine Moseby Daniel M. Parker Stéphanie Périquet John Read Robert J. Scanlon Rebecca Seeto Craig Shuttleworth Michael J. Somers Cottrell T. Tamessar Katherine Tuft Rose Upton Marcia Valenzuela-Molina Adrian Wayne Ryan R. Witt Wolfgang Wüster 《Conservation biology》2019,33(4):760-768
Compassionate conservation focuses on 4 tenets: first, do no harm; individuals matter; inclusivity of individual animals; and peaceful coexistence between humans and animals. Recently, compassionate conservation has been promoted as an alternative to conventional conservation philosophy. We believe examples presented by compassionate conservationists are deliberately or arbitrarily chosen to focus on mammals; inherently not compassionate; and offer ineffective conservation solutions. Compassionate conservation arbitrarily focuses on charismatic species, notably large predators and megaherbivores. The philosophy is not compassionate when it leaves invasive predators in the environment to cause harm to vastly more individuals of native species or uses the fear of harm by apex predators to terrorize mesopredators. Hindering the control of exotic species (megafauna, predators) in situ will not improve the conservation condition of the majority of biodiversity. The positions taken by so-called compassionate conservationists on particular species and on conservation actions could be extended to hinder other forms of conservation, including translocations, conservation fencing, and fertility control. Animal welfare is incredibly important to conservation, but ironically compassionate conservation does not offer the best welfare outcomes to animals and is often ineffective in achieving conservation goals. Consequently, compassionate conservation may threaten public and governmental support for conservation because of the limited understanding of conservation problems by the general public. 相似文献
242.
Various predator-prey, host-pathogen, and competitive interactions can combine to cause density dependence in population growth. Despite this possibility, most empirical tests for density-dependent interactions have focused on single mechanisms. Here we tested the hypothesis that two mechanisms of density dependence, parasitism and a shortage of refuges, jointly influence the strength of density-dependent mortality. We used mark-recapture analysis to estimate mortality of the host species, the bridled goby (Coryphopterus glaucofraenum). Sixty-three marked gobies were infected with a copepod gill parasite (Pharodes tortugensis), and 188 were uninfected. We used the spatial scale at which gobies were clustered naturally (approximately 4 m2) as an ecologically relevant neighborhood and measured goby density and the availability of refuges from predators within each goby's neighborhood. Goby survival generally declined with increasing density, and this decline was steeper for gobies with access to few refuges than for gobies in neighborhoods where refuges were common. The negative effects of high density and refuge shortage were also more severe for parasitized gobies than for gobies free of parasites. This parasite has characteristics typical of emerging diseases and appears to have altered the strength of a preexisting density-dependent interaction. 相似文献
243.
Objectives: This research aims to identify and analyze the factors affecting accident severity through a macroscopic analysis, with a focus on the comparison between inside and outside urban areas. Disaggregate road accident data for Greece for the year 2008 were used. Methods: Two models were developed, one for inside and one for outside urban areas. Because the dependent variable had 2 categories, killed/severely injured (KSI) and slightly injured (SI), the binary logistic regression analysis was selected. Furthermore, this research aims to estimate the probability of fatality/severe injury versus slight injury as well as to calculate the odds ratios (relative probabilities) for various road accident configurations. The Hosmer and Lemeshow statistic and other diagnostic tests were conducted in order to assess the goodness-of-fit of the model. Results: From the application of the models, it appears that inside urban areas 3 types of collisions (sideswipe, rear-end, with fixed object/parked car), as well as involvement of motorcycles, bicycles, buses, 2 age groups (18-30 and older than 60?years old), time of accident, and location of the accident, seem to affect accident severity. Outside urban areas, 4 types of collisions (head-on, rear-end, side, sideswipe), weather conditions, time of accident, one age group (older than 60?years old), and involvement of motorcycles and buses were found to be significant. Conclusions: Factors affecting road accident severity only inside urban areas include young driver age, bicycles, intersections, and collision with fixed objects, whereas factors affecting severity only outside urban areas are weather conditions and head-on and side collisions, demonstrating the particular road users and traffic situations that should be focused on for road safety interventions for the 2 different types of networks (inside and outside urban areas). The methodology and the results of this research may provide a promising tool to prioritize programs and measures to improve road safety in Greece and worldwide. 相似文献
244.
Ecological interaction networks are a valuable approach to understanding plant-pollinator interactions at the community level. Highly structured daily activity patterns are a feature of the biology of many flower visitors, particularly provisioning female bees, which often visit different floral sources at different times. Such temporal structure implies that presence/absence and relative abundance of specific flower-visitor interactions (links) in interaction networks may be highly sensitive to the daily timing of data collection. Further, relative timing of interactions is central to their possible role in competition or facilitation of seed set among coflowering plants sharing pollinators. To date, however, no study has examined the network impacts of daily temporal variation in visitor activity at a community scale. Here we use temporally structured sampling to examine the consequences of daily activity patterns upon network properties using fully quantified flower-visitor interaction data for a Kenyan savanna habitat. Interactions were sampled at four sequential three-hour time intervals between 06:00 and 18:00, across multiple seasonal time points for two sampling sites. In all data sets the richness and relative abundance of links depended critically on when during the day visitation was observed. Permutation-based null modeling revealed significant temporal structure across daily time intervals at three of the four seasonal time points, driven primarily by patterns in bee activity. This sensitivity of network structure shows the need to consider daily time in network sampling design, both to maximize the probability of sampling links relevant to plant reproductive success and to facilitate appropriate interpretation of interspecific relationships. Our data also suggest that daily structuring at a community level could reduce indirect competitive interactions when coflowering plants share pollinators, as is commonly observed during flowering in highly seasonal habitats. 相似文献
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247.
Deborah J. Ballantine Desmond E. Walling Adrian L. Collins Graham J. L. Leeks 《Water, Air, & Soil Pollution: Focus》2006,6(5-6):371-380
Deposition and storage of fine sediment on channel beds represents an important component of a catchment’s sediment budget
and can have important implications for sediment-associated P fluxes, due to storage and remobilisation, and for P concentrations
through water–sediment interactions. Spatial and temporal variations in P content and storage in fine bed sediment have been
studied in two UK lowland catchments, the Rivers Frome and Piddle in Dorset. Fine bed sediment was sampled in representative
reaches on a bi-monthly basis using a re-suspension cylinder, and the resulting samples were analysed for total P, a range
of P fractions and particle size. The results demonstrate significant spatial and temporal variability in PP concentrations
and storage, with maximum and minimum P concentrations and storage occurring in late summer and winter, respectively. Temporal
variations in concentrations reflect residence times of the sediment and ambient P concentrations, while variations in storage
are mainly due to hydrological regimes. Spatial variations reflect catchment characteristics, the location of inputs and local
variations in hydrological and channel bed conditions. 相似文献
248.
Ongoing concerns with regard to the appropriate approach to elicitation of willingness-to-pay responses in contingent valuation studies have led to the development of a number of alternative techniques. One of the most recent, and on the surface, most promising of these is the random card sorting approach (RCS) which has been used for policy purposes to value risk reductions. This paper provides the first formal test of this procedure, comparing it against the widely used payment card (PC) format from which it is developed and whose recognised problems, such as range bias, it claims to address. However, the findings suggest that the RCS procedure is no less vulnerable to range bias than the PC method for eliciting both monetary values of health risk reductions and non-monetary estimates of death rates. Conclusions for future research initiatives are drawn. 相似文献
249.
250.
Jim Graham Nick Young Catherine S. Jarnevich Greg Newman Paul Evangelista Thomas J. Stohlgren 《Environmental management》2013,52(4):929-938
Habitat suitability maps are commonly created by modeling a species’ environmental niche from occurrences and environmental characteristics. Here, we introduce the hyper-envelope modeling interface (HEMI), providing a new method for creating habitat suitability models using Bezier surfaces to model a species niche in environmental space. HEMI allows modeled surfaces to be visualized and edited in environmental space based on expert knowledge and does not require absence points for model development. The modeled surfaces require relatively few parameters compared to similar modeling approaches and may produce models that better match ecological niche theory. As a case study, we modeled the invasive species tamarisk (Tamarix spp.) in the western USA. We compare results from HEMI with those from existing similar modeling approaches (including BioClim, BioMapper, and Maxent). We used synthetic surfaces to create visualizations of the various models in environmental space and used modified area under the curve (AUC) statistic and akaike information criterion (AIC) as measures of model performance. We show that HEMI produced slightly better AUC values, except for Maxent and better AIC values overall. HEMI created a model with only ten parameters while Maxent produced a model with over 100 and BioClim used only eight. Additionally, HEMI allowed visualization and editing of the model in environmental space to develop alternative potential habitat scenarios. The use of Bezier surfaces can provide simple models that match our expectations of biological niche models and, at least in some cases, out-perform more complex approaches. 相似文献