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171.
Irina Herzon Johan Ekroos Jukka RintalaJuha Tiainen Tuomas SeimolaVille Vepsäläinen 《Agriculture, ecosystems & environment》2011,143(1):3-7
The set-aside obligation under the Common Agricultural Policy (CAP) brought widespread benefits for wild farmland species. Shortly after it was abolished in 2008, the national political process in Finland replaced it with a targeted agri-environment scheme for environmental fallow. Though potentially highly valuable, the value of the current scheme for securing biodiversity is yet to be confirmed. This study evaluates the importance of set-asides established under CAP to all birds of open farmland based on national monitoring data from 2001 to 2006. The set-aside fields supported 25-40% more species and held 60-105% more pairs of birds typical of open farmland in comparison with cereal fields within a similar landscape setting. The estimated effect of set-aside presence in farmland on the studied bird species is large enough to trigger considerable changes in bird populations on the national scale. The relevance of the results to the novel agri-environment scheme is discussed. 相似文献
172.
David J.T. Douglas Juliet A. Vickery Tim G. Benton 《Agriculture, ecosystems & environment》2010,135(1-2):127-131
Managing arthropod populations on farmland for conservation purposes, such as food resources for declining farmland birds, requires information on the way distributions vary between crop types, for example under varying sowing regimes. In this study arthropods were sampled during one summer from fields of winter-sown and spring-sown barley. The relative timing of crop development had a strong influence on arthropod abundance between crop types, with winter barley supporting significantly higher abundance of total counts and many individual orders in early summer, but the reverse being the case in late summer. Fields of both crop types that received higher herbicide inputs showed reduced arthropod counts. 相似文献
173.
为科学评估内蒙古辉河国家级自然保护区湿地保护成效,基于定量化、动态性和可操作性原则,构建了保护成效评估指标体系,并以保护区内湿地面积和水鸟多样性的动态监测结果为基础,对2004—2013年保护区湿地保护成效进行了研究. 结果表明:随着辉河国家级自然保护区管理局的组建以及对周边社区放牧和芦苇收割等管控力度的加强,近10 a来湿地保护效果良好,具体表现在保护区内湿地面积基本保持稳定(动态度指数为-0.178%),成片分布趋势增加(平均斑块面积增加53.44%),破碎化程度降低;此外,保护区内水鸟Shannon-Wiener多样性指数和Pielou均匀度指数均增加较为明显,分别增加83.53%和88.50%;物种丰富度和濒危水鸟数量也呈缓慢增加趋势. 构建的湿地保护成效评估指标体系能够在一定程度上反映自然保护区对湿地的管护效果,建议保护区管理局进一步加强气候因素、水鸟生境质量以及辉河上游湿地的监测工作,并依据当地气候变化情况适当补水. 相似文献
174.
Smith SM Gawlik DE Rutchey K Crozier GE Gray S 《Journal of environmental management》2003,68(4):355-366
In the winter-spring of 2001, South Florida experienced one of the worst droughts in its recorded history. Out of a myriad of ecological concerns identified during this time, the potential for catastrophic peat fire and negative impacts to wading bird reproduction emerged as critical issues. Water managers attempted to strike a balance between the environment and protection of water supplies for agriculture and urban interests. It became evident, however, that a broad-scale, integrated way to portray and prioritise ecological stress was lacking in the Florida Everglades, despite this being considered a necessary tool for addressing issues of environmental protection. In order to provide a framework for evaluating various water management operations using real-time information, we developed GIS-based indices of peat-fire risk and wading bird habitat suitability. These indices, based on real physical, chemical, and biological data, describe two ecological conditions that help define the physical and biological integrity of the Everglades. In addition to providing continuous, updated assessments throughout the drought period, we incorporated predictive models of water levels to evaluate how various water management alternatives might exacerbate or alleviate ecological stress during this time. 相似文献
175.
Borhan Mansouri Mohsen Nowrouzi Masoumeh Ariyaee Amin Mishmast Nehi 《Chemistry and Ecology》2013,29(4):326-333
The objective of the present study was to investigate the levels of Cd, Pb, Co, and Cu, in A. chukar, A. griseogularis, and Columba livia, in order to (1) examine the age- and gender-related variation in trace metal accumulation and (2) to determine the significance between metal concentrations in the kidney, liver, and pectoral muscle. Mean concentrations of Cd and Pb in the kidney of A. chukar, A. griseogularis, and C. livia were 3.7, 4.1, and 3.9?µg/g and 15.9, 13.6, and 15.5?µg/g, respectively. In the liver, they were 4.8, 4.3, and 3.9?µg/g and 21.4, 21.3, and 21.1?µg/g, and in the pectoral muscle, 2.3, 2.3, and 2.2?µg/g and 7.1, 7.1, and 7.8?µg/g, respectively. Metal concentrations in three bird species were decreased in the sequence of liver?>?kidney?>?pectoral muscle. Trace metal concentrations in the three species were higher in females than in males. The mean concentrations of Cd in the kidney and liver were higher than the background levels, as well as Pb concentrations in the liver were higher than the toxic level. 相似文献
176.
Elevated levels of selenium have been found in water and aquatic biota downstream from two open-pit coal mines in the Rocky Mountain foothills of Alberta. Birds are particularly sensitive to excessive dietary selenium. However, there is relatively little information on selenium accumulation in birds' eggs on fast-flowing mountain streams. We determined levels of selenium in water samples, caddisfly larvae and eggs of American dippers (Cinclus mexicanus) nesting on the Gregg River, downstream from the mines, and on reference streams in the same general vicinity. Selenium levels (mean, 95% confidence limits) in water samples and caddisflies collected from sites near dipper nests on the Gregg River (water: 4.26, 1.90–9.56 μg L−1; caddisflies: 8.43, 7.51–9.46 μg g dry wt−1) were greater than those collected from sites near nests on reference rivers (water: 0.38, 0.21–0.71 μg L−1; caddisflies: 4.65, 4.35–4.97 μg g dry wt−1). The mean (± 1SE) selenium level in dipper eggs from the Gregg River (6.3 ± 0.2 μg g−1 dry wt) was significantly higher than it was in eggs from reference streams (4.9 ± 0.2 μg g−1 dry wt). Concentrations of selenium in eggs were significantly correlated with those in water samples (r = 0.45). The maximum selenium level in eggs from the Gregg River (9.0 μg g−1) may have been high enough to warrant concern from an ecotoxicological perspective. The American dipper can serve as a useful bioindicator of selenium contamination in mountainous, lotic ecosystems. 相似文献
177.
方言差异对个体环保行为的影响主要依据是文化认同理论,个体对其所属文化群体的情感认同和身份认知,涵盖了对特定文化传统、价值观、信仰、习惯和语言的深刻认同感。该理论指出,文化认同不仅影响着个体对自我身份的认知,也影响着他们对他人、社会群体,以及整个社会的态度和行为。本研究基于中国综合社会调查(Chinese General Social Survey,CGSS)(2013)数据,使用普通最小二乘法(Ordinary Least Squares,OLS)和调节效应模型分析了方言距离对流动人口环保行为的影响及其作用机制。研究结果表明,方言距离总体上显著降低了流动人口的环保行为,且经过内生性和稳健性检验后,这一研究发现依然成立。异质性分析表明,方言距离降低私域环保行为要比公域环保行为更明显,且方言距离降低短期居住者和听说普通话能力较低者的环保行为也更显著。进一步的机制分析发现,较高的环境污染认知、环境重要性认知以及地区环境规制水平均能显著缓解方言距离对环保行为的负面影响。 相似文献
178.
梁土坤 《中国人口.资源与环境》2017,(2):151-159
本文基于南开大学"2013年流动人口管理和服务对策研究问卷调查"的数据,对新生代流动人口定居意愿及其影响因素展开分析,并与老生代流动人口的情况进行比较。发现经济因素对老生代流动人口定居意愿具有显著影响。然而,与之不同的是,职业类型、家庭人均月收入、住房公积金等代表经济因素的指标对新生代流动人口定居意愿的影响不显著。而且,信用卡消费、人均居住面积、居住质量、对城市生活水平的满意度、流入地亲人数、朋友中的本地人数量、日常生活中与本地人的交往频繁程度等代表社会适应因素的指标对新生代流动人口定居意愿具有显著影响;但是,这些社会适应因素对老生代流动人口定居意愿的影响则较为有限。由此可见,流动人口定居意愿影响因素存在显著的代际差异。相对于老生代流动人口而言,新生代流动人口定居意愿的影响因素由经济吸引向社会适应转化。具体而言,新生代流动人口定居意愿的社会适应因素体现在消费方式、居住环境、情感纽带、社会融入、城市评价等五个方面。因此,可以通过增进新生代流动人口的社会适应从而提高其定居意愿。 相似文献
179.
文章结合川渝地区天然气管网调整改造工程-北外环集输气管道建设中水土流失治理监理实施情况,着重介绍了长输管道工程建设中地面开挖破坏造成水土流失的特点及成因,指出在长输管道工程建设中实施水土保持监理工作的法律及技术规范方面的依据,从8个方面提出施工现场水土保持监理的重点,并进行阐述和探讨。最后提出对此项工作的若干认识。 相似文献
180.
Zhang Sifeng Zhang Wenxue Wang Lijian Zhang Li .School of Public Policy Administration China Xi’an Jiaotong University Xi’an Shaanxi China .School of Humanities Social Science 《中国人口.资源与环境(英文版)》2010,8(2)
Based on the definition of migrant workers and migrant workers'social security,systems,policies and regulations and status quo of specific safeguard project of social security have been analyzed.Authors draw following conclusions: China's social security systems of migrant workers show diversification and differentiation trend; national-level policies take on diversification and local-level regulations take on differentiation; social welfare and social assistance have deficiency; coverage rate of social insurance items is extremely low. 相似文献