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Martin Nyffeler Çağan H. Şekercioğlu Christopher J. Whelan 《Die Naturwissenschaften》2018,105(7-8):47
In this paper, we present an estimate of the predation impact of the global population of insectivorous birds based on 103 (for the most part) published studies of prey consumption (kg ha?1 season?1) of insectivorous birds in seven biome types. By extrapolation—taking into account the global land cover of the various biomes—an estimate of the annual prey consumption of the world’s insectivorous birds was obtained. We estimate the prey biomass consumed by the world’s insectivorous birds to be somewhere between 400 and 500 million metric tons year?1, but most likely at the lower end of this range (corresponding to an energy consumption of ≈?2.7?×?1018 J year?1 or ≈?0.15% of the global terrestrial net primary production). Birds in forests account for >?70% of the global annual prey consumption of insectivorous birds (≥?300 million tons year?1), whereas birds in other biomes (savannas and grasslands, croplands, deserts, and Arctic tundra) are less significant contributors (≥?100 million tons year?1). Especially during the breeding season, when adult birds feed their nestlings protein-rich prey, large numbers of herbivorous insects (i.e., primarily in the orders Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, and Orthoptera) supplemented by spiders are captured. The estimates presented in this paper emphasize the ecological and economic importance of insectivorous birds in suppressing potentially harmful insect pests on a global scale—especially in forested areas. 相似文献
484.
Conservation tillage can reduce soil loss; however, the residual herbicides normally used to control weeds are often detected in surface runoff at high levels, particularly if runoff-producing storms occur shortly after application. Therefore, we measured losses of alachlor, atrazine, linuron, and metribuzin from seven small (0.45-0.79-ha) watersheds for 9 yr (1993-2001) to investigate whether a reduced-input system for corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] production with light disking, cultivation, and half-rate herbicide applications could reduce losses compared with chisel and no-till. As a percentage of application, annual losses were highest for all herbicides for no-till and similar for chisel and reduced-input. Atrazine was the most frequently detected herbicide and yearly flow-weighted concentrations exceeded the drinking water standard of 3 microg L(-1) in 20 out of 27 watershed years that it was applied. Averaged for 9 corn yr, yearly flow-weighted atrazine concentrations were 26.3, 9.6, and 8.3 microg L(-1) for no-till, chisel, and reduced-input, respectively. Similarly, flow-weighted concentrations of alachlor exceeded the drinking water standard of 2 microg L(-1) in 23 out of 54 application years and in all treatments. Thus, while banding and half-rate applications as part of a reduced-input management practice reduced herbicide loss, concentrations of some herbicides may still be a concern. For all watersheds, 60 to 99% of herbicide loss was due to the five largest transport events during the 9-yr period. Thus, regardless of tillage practice, a small number of runoff events, usually shortly after herbicide application, dominated herbicide transport. 相似文献
485.
Sophie S. Parker Gregory B. Pauly James Moore Naomi S. Fraga John J. Knapp Zachary Principe Brian V. Brown John M. Randall Brian S. Cohen Thomas A. Wake 《Conservation biology》2018,32(5):1007-1019
When conservation strategies require new, field‐based information, practitioners must find the best ways to rapidly deliver high‐quality survey data. To address this challenge, several rapid‐assessment approaches have been developed since the early 1990s. These typically involve large areas, take many months to complete, and are not appropriate when conservation‐relevant survey data are urgently needed for a specific locale. In contrast, bioblitzes are designed for quick collection of site‐specific survey data. Although bioblitzes are commonly used to achieve educational or public‐engagement goals, conservation practitioners are increasingly using a modified bioblitz approach to generate conservation‐relevant data while simultaneously enhancing research capacity and building working partnerships focused on conservation concerns. We term these modified events expert bioblitzes. Several expert bioblitzes have taken place on lands of conservation concern in Southern California and have involved collaborative efforts of government agencies, nonprofit organizations, botanic gardens, museums, and universities. The results of expert bioblitzes directly informed on‐the‐ground conservation and decision‐making; increased capacity for rapid deployment of expert bioblitzes in the future; and fostered collaboration and communication among taxonomically and institutionally diverse experts. As research and conservation funding becomes increasingly scarce, expert bioblitzes can play an increasingly important role in biodiversity conservation. 相似文献
486.
Sophie Hallstedt Henrik Ny Karl-Henrik Robèrt Göran Broman 《Journal of Cleaner Production》2010,18(8):703-712
This article aims to explore a new approach to assess company decision systems regarding sustainability-related communication and decision support between senior management and product development levels. The assessment approach was developed in theory and its applicability was directly tested in action research in two small and medium-sized companies and two large companies. The results were validated against experiences made by two management consultancies. Our study indicates that successful companies should: (i) integrate sustainability into business goals and plans, backed up by suitable (ii) internal incentives and disincentives and (iii) decision support tools. Our study also indicates that the new assessment approach can be used as a template to assess the current state of sustainability integration in company decision systems. 相似文献
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Joerg Schaller Martin Mkandawire E. Gert Dudel 《Environmental pollution (Barking, Essex : 1987)》2010,158(7):2454-2458
Organic sediments are a main sink for metal pollutants in aquatic systems. However, factors that make sediments a sink of metals and metalloids are still not clear. Consequently, we investigate the role of invertebrate shredders (Gammarus pulex L.) on quality of metal and arsenic fixation into organic partitions of sediment in the course of litter decay with laboratory microcosm experiments. During the decomposition of leaf litter, G. pulex significantly facilitated the development of small particles of organic matter. The capacity of metal fixation was significantly higher in smaller particles than leaf litter and litter residuals. Thus, G. pulex enhanced metal fixation into the organic partition of sediments by virtue of increasing the amount smaller particles in the aquatic system. Furthermore, invertebrates have a significant effect on formation of dissolved organic matter and remobilization of cobalt, molybdenum and cesium, but no significant effect on remobilization of all other measured elements. 相似文献
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Chhatra Mani Sharma Bjørn Olav Rosseland Marit Almvik Ole Martin Eklo 《Environmental pollution (Barking, Essex : 1987)》2009,157(8-9):2452-2458
Organochlorine pollutants in the major fish species (pike Esox lucius, perch Perca fluviatilis, and roach Rutilus rutilus) of Lake Årungen, Norway, were investigated after an extensive removal of large pike in 2004. The organochlorine pollutants detected in fish liver samples in 2005 were dichlorodiphenyltrichloroethane (DDTs), polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and heptachlor epoxide (HCE). DDTs were the dominant among all analyzed OCs. ΣPCB and HCB, detected in fish from two clearly distinct trophic levels (prey and predators), give an indication of biomagnification. All OC concentrations in female pike were significantly lower compared to males, which might be due to the removal of high concentrations of pollutants in roe during spawning. 相似文献