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Hesitation behaviour of hoverflies Sphaerophoria spp. to avoid ambush by crab spiders 总被引:1,自引:0,他引:1
Pollinators possess several antipredator adaptations that minimise predation risk during foraging. In addition to morphological adaptations, hoverflies might have behavioural antipredator adaptations. We conducted three field experiments to investigate whether the "hesitation behaviour" of hoverflies Sphaerophoria spp., moving backwards and forwards in front of a flower, is effective in avoiding ambush predators on flowers. First, we compared the behaviour of different flower visitors, including several bees and other hoverflies, with Sphaerophoria spp. behaviour. Only Sphaerophoria spp. exhibited the hesitation behaviour in front of flowers. The flight behaviour was observed more frequently before landing on flowers than on leaves. Second, we investigated rejection by Sphaerophoria spp. to artificially placed corpses of the crab spider Thomisus labefactus. The rejection rate of flowers with a crab spider placed on or under it was significantly higher than that of non-treated flowers. Moreover, the presence of a spider on the flower decreased the number of hesitation displays, compared with non-treated flowers. Finally, to determine whether hesitation behaviour could be a consequence of floral assessment, we investigated hoverfly rejection of previously foraged flowers. Sphaerophoria spp. did not reject flowers that had been visited by the same individual or conspecifics within 3 min. We suggest that hesitation behaviour may be adaptive, enabling assessment of predation risk and hence avoiding ambush predators on flowers. 相似文献
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近岸海域生态系统服务功能监测的指标体系研究 总被引:1,自引:0,他引:1
按照海洋生态系统服务功能的特点,对监测海洋生态服务功能的指标体系进行了初步研究。具体分为三个一级指标,包括供给功能、调节功能和支持功能,又将如上一级指标细分为十个二级指标。本文旨在运用生态系统服务功能的理论框架和方法,为完善近岸海域生态监测的指标体系奠定基础。 相似文献
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Matthew J. Eckelman Reid J. LifsetIoannis Yessios Ken Panko 《Journal of Cleaner Production》2011,19(11):1273-1278
Second Life is a virtual, open-access, and user-generated environment that has served as a platform for hosting everything from rock concerts to scientific conferences. Many institutions have also used Second Life as an educational tool, for example by, showcasing scientific exhibits or embedding video and images for learning purposes. Here we discuss the creation and use of an interactive, virtual industrial facility - the Elihu Paper Company - as a way to complement a traditional facility tours in a course in industrial environmental management. Virtual facilities offer a number of educational advantages over real-life ones: they are always open and available for tours, they can be accessed instantaneously from anywhere where there is an adequate internet connection, and most importantly, tours and embedded information can be tailored to specific educational objectives. Our experience in using Elihu Paper as a formal facility visit for the past several years shows that students had significantly more time than usual to ask questions, could and did explore the facility independently, and were still able to produce facility reports that fulfilled the educational objectives of the visits, including mapping material flows and explaining pollution prevention and sustainability opportunities. 相似文献
708.
Suvi LehtorantaAuthor Vitae Ari NissinenAuthor VitaeTuomas MattilaAuthor Vitae Matti MelanenAuthor Vitae 《Journal of Cleaner Production》2011,19(16):1865-1875
Industrial symbioses (ISs) and eco-industrial parks (EIPs) are key concepts of industrial ecology (IE). The aim of ISs and EIPs is to minimise inefficient material and energy use by utilising local by-product and energy flows. Industrial symbioses tend to develop through spontaneous action of economic actors, for gaining of economic benefit, but these systems can be designed and promoted via policy instruments as well. A literature review showed that national programmes for eco-industrial parks can be found in different parts of the world. In the action programmes and other sustainable consumption and production (SCP) policy documents of the EU, on the other hand, industrial symbioses gain less recognition as a path to enhanced sustainable production. In this article, we consider this and also analyse how the evolution and environmental performance of an industrial symbiosis system centred on a Finnish pulp and paper mill have been affected by SCP policy instruments. With regard to the system forming the subject of the case study, and Finnish industrial systems in general, policy instruments have succeeded in reducing emissions but not in systematically encouraging operators toward symbiosis-like activities. All in all, few studies exist on the overall impact of policy instruments promoting design of eco-industrial parks. It is not self-evident that symbiosis-like production systems would be sustainable in every case, as the background assumptions for political promotion of EIPs suggest. We concluded that industrial symbioses should be analysed and developed on a life cycle basis, with documentation of the real environmental benefits due to efficient resource use and decreased emissions in comparison to standalone production. ISs can then bring eco-competitiveness to companies in relation to SCP tools, such as environmental permits, ecolabels, and future product regulation based on the Ecodesign Directive in Europe. Indirect encouragement of symbiosis through land-use regulation and planning, in such a way that material fluxes between companies are possible both in operations and in financial terms, may prove effective. The same holds for waste policies that encourage increased reuse of a company’s waste by other enterprises. 相似文献
709.
燕山北部山地人工林和天然次生林的生物碳贮量 总被引:1,自引:0,他引:1
为了了解人工林与天然次生林碳汇功能的差异,以燕山北部山地华北落叶松人工林和杨桦天然次生林为研究对象,对不同年龄阶段的两种林分的生物碳贮量进行了研究。结果表明:13、18、28 a生杨桦天然次生林总生物碳贮量分别为27.33、35.77、46.13 t/hm2,9、13、30 a华北落叶松人工林分别为21.97、34.14、55.62 t/hm2; 0~13 a,14~18 a,19~28 a杨桦林生物总碳贮量的年碳积累速率分别为2.10、1.69、1.04 t/hm2, 0~9 a,10~13 a,14~30 a落叶松林分别为2.44、3.04、1.34 t/hm2;华北落叶松单木生物量增长速率明显高于白桦和山杨,在10~25 a的年龄段,落叶松生长速度是白桦、山杨的1.63~5.83、2.26~7.87倍;华北落叶松的BCEF(生物量转化和扩展因子)和BEF(生物量扩展因子)随年龄和胸径的增长有逐渐降低的趋势,而白桦和山杨的两个参数则有逐渐增加的趋势。由此得出结论,在燕山北部山地,与杨桦天然次生林相比,华北落叶松人工林表现出更强的碳吸存能力,该地区大面积的华北落叶松幼、中龄林具有巨大的碳汇潜力;同时,使用生物量碳计量参数时应考虑树种、林龄和胸径的差异。 相似文献
710.
Tom B. Letessier Laura Mannocci Brittney Goodwin Clare Embling Asha de Vos R. Charles Anderson Simon N. Ingram Andy Rogan Samuel T. Turvey 《Conservation biology》2023,37(3):e14043
Many species are restricted to a marginal or suboptimal fraction of their historical range due to anthropogenic impacts, making it hard to interpret their ecological preferences from modern-day data alone. However, inferring past ecological states is limited by the availability of robust data and biases in historical archives, posing a challenge for policy makers . To highlight how historical records can be used to understand the ecological requirements of threatened species and inform conservation, we investigated sperm whale (Physeter macrocephalus) distribution in the Western Indian Ocean. We assessed differences in information content and habitat suitability predictions based on whale occurrence data from Yankee whaling logs (1792–1912) and from modern cetacean surveys (1995–2020). We built maximum entropy habitat suitability models containing static (bathymetry-derived) variables to compare models comprising historical-only and modern-only data. Using both historical and modern habitat suitability predictions we assessed marine protected area (MPA) placement by contrasting suitability in- and outside MPAs. The historical model predicted high habitat suitability in shelf and coastal regions near continents and islands, whereas the modern model predicted a less coastal distribution with high habitat suitability more restricted to areas of steep topography. The proportion of high habitat suitability inside versus outside MPAs was higher when applying the historical predictions than the modern predictions, suggesting that different marine spatial planning optimums can be reached from either data sources. Moreover, differences in relative habitat suitability predictions between eras were consistent with the historical depletion of sperm whales from coastal regions, which were easily accessed and targeted by whalers, resulting in a modern distribution limited more to steep continental margins and remote oceanic ridges. The use of historical data can provide important new insights and, through cautious interpretation, inform conservation planning and policy, for example, by identifying refugee species and regions of anticipated population recovery. 相似文献