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1.
Site-specific estimates of the values of spatial configuration and forest composition are presented. Amenity values of forest patches are found to vary the most by urban and sprawling development patterns of specific areas and forest types. For example, smaller patches of deciduous forest are more highly valued in the urban and sprawling areas of Greensboro, North Carolina, whereas larger patches of deciduous forest are more highly valued in the urban and sprawling areas of Greenville, South Carolina. Within the Greenville and Greensboro areas, visible landscape complexity is highly valued for deciduous and evergreen forest patches, whereas lower visible landscape complexity, i.e., smoothly trimmed forest patch boundaries, is highly valued for mixed forest patches.  相似文献   

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针对目前土壤-农作物镉污染问题,以浙江省40个县(市、区)主要优势农产品产区为研究对象,在粮食、油菜、蔬菜种植地以及茶园和果园土壤中共采集898个单元土壤样品及相对应的五大类农作物,并对其镉含量进行分析评价;同时采用富集系数比较不同农作物对土壤重金属镉的吸收差异。结果表明,研究区产地土壤和农作物的镉含量存在一定程度超标,土壤超标率为10.69%,农作物超标率为4.57%。不同农作物对土壤镉的富集系数差异较大,变化范围在0.002~0.257之间。土壤-农作物镉含量的相关性并不显著。  相似文献   

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汪志宇  马小杰 《四川环境》2021,40(1):109-116
饮用水中可溶性氟化物是公众摄入氟的主要途径,其含量水平影响人体健康.分别于2015~2017年的丰水期和枯水期6次随机采集监测了嘉陵江下游52个饮用水样中氟化物含量,并基于地理信息系统平台和健康风险指数法进行了评价.结果表明,该区域饮用水中氟化物浓度平均为0.20~0.25 mg/L.除2015年部分样点外,其余样点的...  相似文献   

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This article discusses critical comparisons between the human and nonhuman abolitionist movements in the United States. The modern nonhuman abolitionist movement is, in some ways, an extension of the anti-slavery movement of the eighteenth and nineteenth centuries and the ongoing human Civil Rights movement. As such, there is considerable overlap between the two movements, specifically in the need to simultaneously address property status and oppressive ideology. Despite intentional appropriation of terminology and numerous similarities in mobilization efforts, there has been disappointingly little academic discussion on this relationship. There are significant contentions regarding mobilization and goal attainment in the human abolitionist movement that speak to modern collective action on behalf of other animals. This article will explore the human abolitionist movement and discuss possible applications of movement organization, tactical repertoires, and goal attainment to the current nonhuman animal rights movement. Specifically, the utility of violence and legislative activism in the antislavery movement are discussed as potentially problematic approaches to abolishing nonhuman animal exploitation. Alternatively, the nonhuman animal rights focus on consumer resistance and nonviolence represent an important divergence in abolitionist mobilization.  相似文献   

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Biodiversity maintenance and soil improvement are key sustainable forestry objectives. Research on the effects of bamboo forest management on plant diversity and soil properties are therefore necessary in bamboo-growing regions, such as southeastern China’s Shunchang County, that have not been studied from this perspective. We analyzed the effects of different Phyllostachys pubescens proportions in managed forests on vegetation structure and soil properties using pure Cunninghamia lanceolata forests as a contrast, and analyzed the relation between understory plants and environmental variables (i.e., topography, stand and soil characteristics) by canonical correspondence analysis (CCA). The forest with 80% P. pubescens and 20% hardwoods (such as Phoebe bournei, Jatropha curcas, Schima superba) maintained the highest plant diversity and best soil properties, with significantly higher plant diversity than the C. lanceolata forest, and better soil physicochemical and biological properties. The distribution of understory plants is highly related to environmental factors. Silvicultural disturbance strongly influenced the ability of different bamboo forests to maintain biodiversity and soil quality under extensive management, and the forest responses to management were consistent with the intermediate-disturbance hypothesis (i.e., diversity and soil properties were best at intermediate disturbance levels). Our results suggest that biodiversity maintenance and soil improvement are important management goals for sustainable bamboo management. To achieve those objectives, managers should balance the inputs and outputs of nutrients and protect understory plants by using appropriate fertilizer (e.g., organic fertilizer), adjusting stand structure, modifying utilization model and the harvest time, and controlling the intensity of culms and shoots harvests.  相似文献   

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Just as a stream of genetically modifiedcrops looked set to be approved for commercialproduction in the European Union, the approvalprocedure appears to have become bogged down onceagain by disagreements among and within member states.Old controversies have resurfaced in new forms. Theintractability of the issues suggests that theregulatory procedure has had too narrow a focus,leaving outside its boundary many of the morefundamental aspects that cause people in the EuropeanUnion most concern. Regulators have come underconsiderable pressure to ensure their risk assessmentdecisions are soundly science-based. Ethical issueshave been deemed to lie beyond the scope of theregulatory procedure, as a matter to be consideredseparately by professional ethicists. Yet it has beensuggested that all environmental controversies at rootinvolve disputes about fundamental ethical principles.This paper examines how the ethical issues arecurrently suppressed or sidelined. It discusses how anappreciation of systems thinking and a check on thevalues that underpin decisions, using boundary testingquestions, might contribute to a more constructiveregulatory dialogue, with ethical issues considered asintegral in a way that takes better account ofpeople's concerns.  相似文献   

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Across the Americas, biofuels production systems are diverse due to geographic conditions, historical patterns of land tenure, different land use patterns, government policy frameworks, and relations between the national state and civil society, all of which shape the role that biofuels play in individual nations. Although many national governments throughout the Americas continue to incentivize growth of the biofuels industry, one key challenge for biofuels sustainability has been concern about its social impacts. In this article, we discuss some of the key social issues and tensions related to the recent expansion of biofuels production in Mexico, Colombia, and Brazil. We argue that a process of “simplification” of ecological and cultural diversity has aided the expansion of the biofuels frontier in these countries, but is also undermining their viability. We consider the ability of governments and non-state actors in multi-stakeholder initiatives (MSI) to address social and environmental concerns that affect rural livelihoods as a result of biofuels expansion. We analyze the tensions between global sustainability standards, national level policies for biofuels development, and local level impacts and visions of sustainability. We find that both government and MSI efforts to address sustainability concerns have limited impact, and recommend greater incorporation of local needs and expertise to improve governance.  相似文献   

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