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排序方式: 共有678条查询结果,搜索用时 31 毫秒
551.
Poliana Cardoso-Gustavson Francine Faia Fernandes Edenise Segala Alves Mariana Pereira Victorio Barbara Baesso Moura Marisa Domingos Caroline Albuquerque Rodrigues Andreza Portella Ribeiro Catarina Carvalho Nievola Ana Maria G Figueiredo 《Environmental science and pollution research international》2016,23(2):1779-1788
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Sara Dubois Nicole Fenwick Erin A. Ryan Liv Baker Sandra E. Baker Ngaio J. Beausoleil Scott Carter Barbara Cartwright Federico Costa Chris Draper John Griffin Adam Grogan Gregg Howald Bidda Jones Kate E. Littin Amanda T. Lombard David J. Mellor Daniel Ramp Catherine A. Schuppli David Fraser 《Conservation biology》2017,31(4):753-760
Human–wildlife conflicts are commonly addressed by excluding, relocating, or lethally controlling animals with the goal of preserving public health and safety, protecting property, or conserving other valued wildlife. However, declining wildlife populations, a lack of efficacy of control methods in achieving desired outcomes, and changes in how people value animals have triggered widespread acknowledgment of the need for ethical and evidence‐based approaches to managing such conflicts. We explored international perspectives on and experiences with human–wildlife conflicts to develop principles for ethical wildlife control. A diverse panel of 20 experts convened at a 2‐day workshop and developed the principles through a facilitated engagement process and discussion. They determined that efforts to control wildlife should begin wherever possible by altering the human practices that cause human–wildlife conflict and by developing a culture of coexistence; be justified by evidence that significant harms are being caused to people, property, livelihoods, ecosystems, and/or other animals; have measurable outcome‐based objectives that are clear, achievable, monitored, and adaptive; predictably minimize animal welfare harms to the fewest number of animals; be informed by community values as well as scientific, technical, and practical information; be integrated into plans for systematic long‐term management; and be based on the specifics of the situation rather than negative labels (pest, overabundant) applied to the target species. We recommend that these principles guide development of international, national, and local standards and control decisions and implementation. 相似文献
554.
The capacity of humic acid extracted from organic waste (HAw) to reduce Cr(Ⅵ) was tested at pH 2.5,4 and 6 and compared with coal-derived humic acid (HAc).HAw was more effective than HAc in reducing Cr(Ⅵ).The kinetics of Cr(Ⅵ) reductions depended strongly on pH.The calculation of the apparent rate coefficients indicated that HAw was more efficient at reducing Cr(Ⅵ) than HAc,but was also more efficient than HAs from soil and peat.The reduction capability of HAs depends on the type of functional groups (i.e.,thiols and phenols) present,rather than the free radicals.HAw was more efficient at reducing Cr(Ⅵ) than HAc because more reactive phenols were present,i.e.,methoxy-and methyl-phenols. 相似文献
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Janusz Jankowiak Barbara Szpakowska Jerzy Bienkowski 《Ambio-人类环境杂志》2003,32(6):418-423
20世纪90年代波兰的政局发生了变革,由此所带来的农业转型对农业土地利用结构产生了根本性的改变.随着饲料作物比例的下降,粮食作物的比重相应地增加.此外,化学肥料的使用也相应减少了.在畜牧业中,牲畜存栏数表现出了急剧下降,这也导致了有机肥使用量的降低.耕作模式的改变和较低的肥料使用水平使土壤中的有机物含量下降,这有可能使土壤质量下降.由于在大波兰地区广泛存在轻质土壤,而且这类土壤中的养分可以很容易地被淋溶到地下水中,因此上述现象在该地区表现得极为突出.研究发现,在农业景观中的许多负面影响可以通过建立农田防护林带予以缓和.我们的结论是农田防护林带可以有效地控制流域的养分流失. 相似文献
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Barbara L. Peckarsky Angus R. McIntosh Christopher C. Caudill Jonas Dahl 《Behavioral ecology and sociobiology》2002,51(6):530-537
Large size often confers a fitness advantage to female insects because fecundity increases with body size. However, the fitness benefits of large size for male insects are less clear. We investigated the mating behavior of the mayfly Baetis bicaudatus to determine whether the probability of male mating success increased with body size. Males formed mating aggregations (swarms) ranging from a few to hundreds of individuals, 1-4 m above the ground for about 1.5-2 h in the early morning. Females that flew near swarms were grabbed by males, pairs dropped to the vegetation where they mated and then flew off individually. Some marked males returned to swarms 1, 2 or 3 days after marking. Larger males swarmed near spruce trees at the edges of meadows, but the probability of copulating was not a function of male body size (no large male advantage). Furthermore, the potential fitness advantage of mating with larger, more fecund females was not greater for large males (no size-assortative mating). However, the sizes of copulating males were significantly less variable than those of non-mating males collected at random in swarms. Intermediate male size may be optimal during mating because of trade-offs between flight agility and longevity or competitive ability. Results of this study are consistent with the hypotheses that there is stabilizing selection on adult male body size during mating, and that male body size in this species may be influenced more by selection pressures acting on larvae than on adults. 相似文献
560.
Kevin C. Weng Andre M. Boustany Peter Pyle Scot D. Anderson Adam Brown Barbara A. Block 《Marine Biology》2007,152(4):877-894
Satellite telemetry studies of 20 adult and sub-adult white sharks (360–530 cm estimated total length (TL)) in the eastern
North Pacific during 1999–2005 revealed long distance seasonal migrations from the coast of California to an offshore focal
area 2,500 km west of the Baja Peninsula, as well as the Hawaii Islands. Three tags were recovered allowing detailed behavioral
analyses, including one shark’s migration cycle from the coast to the offshore focal area and back. While near pinniped rookeries
in autumn and winter, sharks avoided the surface and used water to 50 m depth, consistent with a silhouette-based hunting
strategy. Offshore migrations were initiated during November–March and followed periods of decreasing pinniped abundance.
Migrations were highly directed, taking 23 ± 5 days to reach the offshore focal area along similar paths among sharks and
years, defining a migration corridor. Sharks exhibited a broad depth distribution (0–644 m) in the offshore focal area, and
remained there for up to 167 days during spring and summer, though primary productivity and fishery data suggest that forage
resources are scarcer there than in other regions of the eastern North Pacific. Archival data from one shark revealed intensive
oscillatory movements while in the offshore focal area, a behavior that may be related to foraging or mating. Sharks traveling
to Hawaii remained near the islands up to 122 days, potentially feeding on pelagic fishes and marine mammals that concentrate
around the islands.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献