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21.
Efficiency,costs and trade-offs in marine reserve system design 总被引:1,自引:0,他引:1
Romola?R.?StewartEmail author Hugh?P.?Possingham 《Environmental Modeling and Assessment》2005,10(3):203-213
With marine biodiversity conservation the primary goal for reserve planning initiatives, a site's conservation potential is
typically evaluated on the basis of the biological and physical features it contains. By comparison, socio-economic information
is seldom a formal consideration of the reserve system design problem and generally limited to an assessment of threats, vulnerability
or compatibility with surrounding uses. This is perhaps surprising given broad recognition that the success of reserve establishment
is highly dependent on widespread stakeholder and community support. Using information on the spatial distribution and intensity
of commercial rock lobster catch in South Australia, we demonstrate the capacity of mathematical reserve selection procedures
to integrate socio-economic and biophysical information for marine reserve system design. Analyses of trade-offs highlight
the opportunities to design representative, efficient and practical marine reserve systems that minimise potential loss to
commercial users. We found that the objective of minimising the areal extent of the reserve system was barely compromised
by incorporating economic design constraints. With a small increase in area (<3%) and boundary length (<10%), the economic
impact of marine reserves on the commercial rock lobster fishery was reduced by more than a third. We considered also how
a reserve planner might prioritise conservation areas using information on a planning units selection frequency. We found
that selection frequencies alone were not a reliable guide for the selection of marine reserve systems, but could be used
with approaches such as summed irreplaceability to direct conservation effort for efficient marine reserve design. 相似文献
22.
Ariel G. Spanowicz Fernanda Zimmermann Teixeira Jochen A. G. Jaeger 《Conservation biology》2020,34(5):1210-1220
Mortality of animals on roads is a critical threat to many wildlife populations and is poised to increase strongly because of ongoing and planned road construction. If these new roads cannot be avoided, effective mitigation measures will be necessary to stop biodiversity decline. Fencing along roads effectively reduces roadkill and is often used in combination with wildlife passages. Because fencing the entire road is not always possible due to financial constraints, high-frequency roadkill areas are often identified to inform the placement of fencing. We devised an adaptive fence-implementation plan to prioritize road sections for fencing. In this framework, areas along roads of high, moderate, and low levels of animal mortality (respectively, roadkill hotspots, warmspots, and coldspots) are identified at multiple scales (i.e., in circles of different diameters [200–2000 m] in which mortality frequency is measured). Fence deployment is based on the relationship between the amount of fencing being added to the road, starting with the strongest roadkill hotspots, and potential reduction in road mortality (displayed in mortality-reduction graphs). We applied our approach to empirical and simulated spatial patterns of wildlife–vehicle collisions. The scale used for analysis affected the number and spatial extent of roadkill hot-, warm-, and coldspots. At fine scales (e.g., 200 m), more hotspots were identified than at coarse scales (e.g., 2000 m), but combined the fine-scale hotspots covered less road and less fencing was needed to reduce road mortality. However, many short fences may be less effective in practice due to a fence-end effect (i.e., animals moving around the fence more easily), resulting in a trade-off between few long and many short fences, which we call the FLOMS (few-long-or-many-short) fences trade-off. Thresholds in the mortality-reduction graphs occurred for some roadkill patterns, but not for others. Thresholds may be useful to consider when determining road-mitigation targets. The existence of thresholds at multiple scales and the FLOMS trade-off have important implications for biodiversity conservation. 相似文献
23.
基于生产可能性边界的黄河三角洲湿地生态系统服务权衡强度 总被引:3,自引:0,他引:3
提出了一种基于生产可能性边界(PPF)的湿地生态系统服务权衡强度计算方法,包括湿地生态系统服务定量评估、权衡关系判定、PPF曲线绘制和权衡强度计算四个步骤。以黄河三角洲湿地为研究对象,对保护情景、现状发展情景及开发情景三种土地利用发展模式下的主导生态系统服务进行了定量化权衡分析。结果表明:各生态系统服务间呈现显著相关关系(R2≥0.9,P<0.01),各发展情景下,栖息地质量与碳储量之间均为协同关系;物质生产与栖息地质量间均为权衡关系,排序为保护情景<基期<现状发展情景<开发情景;而对于物质生产与碳储量之间,在保护及现状发展情景下存在协同关系;而开发情景下转变为权衡关系。该模型通过灵活比较不同生态服务间权衡关系分析进行系列管理规划的方案优选,为实现区域可持续发展提供科学依据。 相似文献
24.
Lisa Kenney Douglas Bessette Joseph Arvai 《Journal of Environmental Planning and Management》2015,58(5):855-873
Decisions about energy in developing communities are challenging from a technical standpoint, and because of the unique characteristics that typify them, e.g. limited infrastructure and government budgets, complex social and political arrangements, and economic vulnerability. Against the backdrop of these challenges, the government of Canada's Northwest Territories (NWT) is attempting to reform the region's energy system. This paper provides insights from the decision sciences, stemming from our work on the NWT's energy planning process, about how to structure decisions about energy development and delivery so as to effectively meet a range of stakeholders’ objectives in a transparent and inclusive manner. 相似文献
25.
Refugia-based conservation offers long-term effectiveness and minimize uncertainty on strategies for climate change adaptation. We used distribution modelling to identify climate change refugia for 617 terrestrial mammals and to quantify the role of protected areas (PAs) in providing refugia across South America. To do so, we compared species potential distribution across different scenarios of climate change, highlighting those regions likely to retain suitable climatic conditions by year 2090, and explored the proportion of refugia inside PAs. Moist tropical forests in high-elevation areas with complex topography concentrated the highest local diversity of species refugia, although regionally important refugia centers occurred elsewhere. Andean–Amazon forests contained climate change refugia for more than half of the continental species’ pool and for up to 87 species locally (17 × 17 km2 grid cell). The highlands of the southern Atlantic Forest also included megadiverse refugia for up to 76 species per cell. Almost half of the species that may find refugia in the Atlantic Forest will do so in a single region—the Serra do Mar and Serra do Espinhaço. Most of the refugia we identified, however, were not in PAs, which may contain <6% of the total area of climate change refugia, leaving 129–237 species with no refugia inside the territorial limits of PAs of any kind. Our results reveal a dismal scenario for the level of refugia protection in some of the most biodiverse regions of the world. Nonetheless, because refugia tend to be in high-elevation, topographically complex, and remote areas, with lower anthropogenic pressure, formally protecting them may require a comparatively modest investment. 相似文献
26.
27.
Biosynthetic origin of carbon-based secondary compounds: cause of variable responses of woody plants to fertilization? 总被引:10,自引:0,他引:10
Erkki Haukioja Vladimir Ossipov Julia Koricheva Tuija Honkanen Stig Larsson Kyösti Lempa 《Chemoecology》1998,8(3):133-139
Summary. We propose that variation in the responses of carbon-based secondary compounds to fertilization in woody plants has a biosynthetic
cause. The synthesis of phenylpropanoids and derived compounds (e.g., condensed tannins) competes directly with the synthesis of proteins, and therefore with plant growth, because of a common
precursor, phenylalanine. In contrast, the biosynthesis of terpenoids and of hydrolyzable tannins proceeds presumably without
direct competition with protein synthesis. Therefore, accelerated plant growth induced by fertilization may cause a reduction
in concentrations of phenylpropanoids but may affect less or not at all the levels of other classes of secondary compounds.
A meta-analysis based on fertilization experiments with 35 woody plant species supported the predicted differences fertilizing
significantly decreased concentrations of phenylpropanoids but not of terpenoids or hydrolyzable tannins.
Received 14 May 1998; accepted 23 June 1998. 相似文献
28.
运用委托代理理论基本原理,分析了节能管理中政府与企业的利益关系;侧重分析了作为委托者的政府与作为代理人的企业在节能问题上的理性水平差异,以及由此决定的双方在行为选择上的不同.研究表明:“委托-代理”模型是一个富有效率的机制,在委托代理机制下,政府和企业在节能上的利益具有一致性.在一定条件下,地方政府通过改变激励策略,不仅可以使企业的节能努力水平产生变化,还会使信息不对称的格局发生改变,实现节能调控的帕累托最优;企业获得财务意义上的好处,地方政府不仅因节能调控成效显著而得到中央的奖励,还会因其良好的政府形象而得到公众的支持. 相似文献
29.
Determinants of diet in free-ranging baboons Papio anubis were investigated. Foods and non-foods differed significantly in chemical composition, the former being higher in protein and lower in fibre and phenolics. Within the range of items selected, biomass was found to be the single most important factor affecting percentage of total intake and time spent feeding (Figure 1). When this effect of biomass was statistically controlled, independent effects of chemical composition (primarily protein content) and harvesting rate were found. However, while the harvesting rates of foods were positively related to their percentage contribution to total intake, they were either uncorrelated, or, in one case, actually negatively correlated with the percentage of feeding time. A post-hoc model based on Charnov's (1976) marginal value theorem is developed to account for these latter results, and direct evidence for rate-maximising patch use is then presented. It is argued that the apparent complexity of primate diets may in large part be reducible to relatively simple optimization criteria. 相似文献
30.
Individual-level variation in resource use occurs in a broad array of vertebrate and invertebrate taxa and may have important
ecological and evolutionary implications. In this study, we measured the degree of individual-level variation in prey preference
of the hunting wasp Trypoxylon albonigrum, which inhabits the Atlantic Forest in southeastern Brazil. This wasp captures several orb-weaving spider genera to provision
nests. Individuals consistently specialized on a narrow subset of the prey taxa consumed by the population, indicating the
existence of significant individual-level variation in prey preferences. The population niche was broader in the wet season
in terms of both prey size and taxa. In the case of prey size, the population niche expansion was achieved via increased individual
niche breadths, whereas in the case of prey taxa, individual niches remained relatively constrained, and the population niche
expanded via increased interindividual variation. The observed pattern suggests the possibility of functional trade-offs associated
with the taxon of the consumed prey. The nature of the trade-offs remains unknown, but they are likely related to learning
in searching and/or handling prey. We hypothesize that by specializing on specific prey taxa, individuals increase foraging
efficiency, reducing foraging time and ultimately increasing reproductive success. 相似文献