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931.
In this paper, an economic model was constructed to determine the optimal wolf population and distribution across the Northern Rocky Mountains. Both ecological and economic concepts were incorporated in an implicitly spatial social welfare maximization problem. This interdisciplinary model relies on multiple data sources, including current wolf population and distribution information, opportunity cost to local landowners, and contingent valuation studies to determine willingness-to-pay for wolves. Economic models tend to externalize ecological concerns and ecological models often omit the complex human dimensions of conservation policy. Accordingly, this model can serve as a guide for integrating best practices from both fields. The model presented here is sufficiently general to apply to wolves in other ecosystems and to other highly interacting species such as beavers and bison. The Northern Rocky Mountain wolf was used as an example of how this economic model works, but this model can be applied far more broadly.  相似文献   
932.
Evidence of the presence of a group of sei whales (Balaenoptera borealis) detected around drifting fish aggregating devices (FADs) was provided by omnidirectional multi‐beam sonar during a survey off the Seychelles (Indian Ocean). The short visit by the sei whales produced a significant change in the behaviour of the fish assemblage associated with the FAD. There was first a significant increase in fish density when the whales approached the FAD, then a marked decrease after the whales had moved away from the FAD. Furthermore, the fish density was still low, 3 h after the whales had left the FAD. We assume that the presence and behaviour of the sei whales led some of the fish initially associated with the FAD to move away from it. There has been a considerable increase in the use of drifting artificial FADs in the Indian Ocean in recent decades. The frequency of cetacean visits to drifting FADs in the Indian Ocean is unknown, but they may have a major impact on assemblages of pelagic fish species around FADs. The effect of marine mammals on FAD‐associated fish could be relevant to the ecological trap theory (FAD acting as a trap for their associated fish) because of their impact on the dynamics of fish aggregation processes, through commensalism and/or predator–prey interactions.  相似文献   
933.
Three coastal and three lagoonal sites located in Greece (Eastern Mediterranean) were selected to test and intercalibrate classification methods developed for benthic invertebrates ecological quality assessments. These methods were developed for the purposes of the European Water Framework Directive which is a European legislation adopted for the protection and improvement of the coastal and transitional waters. However, through testing these methods, this work addresses in general the issue of determining and comparing the ecological status of the coastal and transitional macrobenthic communities in Eastern Mediterranean ecosystems. Among methods tested were the biotic indices AMBI and BENTIX, the multivariate method M-AMBI and the biomass size structure index ISD in lagoonal sites only. ISD index is a rather new method developed especially for transitional ecosystems and in this contribution its performance is intercalibrated with the other benthic classification metrics. Comparison and intercalibration of the indices results in assessing the ecological quality status (EQS) are presented graphically and statistically performing the Kappa analysis. Results of the comparison and the indices' performance are evaluated based on the knowledge of the sites' environmental condition and baseline studies. Based on an extended dataset of coastal and transitional ecosystems benthic invertebrates, an evaluation of each index performance and effectiveness is attempted through an insight and comparative analysis of each methods' structure and design. Results showed that in these Eastern Mediterranean coastal sites the BENTIX index seems to give a more biologically relevant classification and gives a higher confidence level regarding the classification compared to the other indices. In the coastal areas AMBI showed a tendency for the "good" class classification, while the factorial M-AMBI gave more consistent results with the BENTIX. In the lagoonal sites the biotic indices tested were not proved efficient enough and the biomass based ISD index proved more appropriate for these ecosystems. AMBI showed the highest agreement with the ISD which is due to the better performance of this index in the slightly and moderately polluted lagoons, compared to the other indices. However, AMBI failed to classify the polluted lagoon, in which case the BENTIX gave a more relevant classification.  相似文献   
934.
The implementation of the European Water Framework Directive (WFD) requires evaluation of the ecological status (ES) of benthic communities in coastal and transitional water systems, and the intercalibration of assessment methodologies therefore becomes a research challenge. Our aim was to test the suitability of applying the M-AMBI index to assess the status of the Eo estuary (northern coast of Spain). Our results showed that M-AMBI was influenced by the natural variability of benthic communities, and presented an apparent dependence on habitat characteristics. Consequently, the definition of homogeneous areas in transitional water systems should be based on the salinity gradient combined with other factors. To achieve an accurate ES assessment, habitat-specific reference conditions should then be defined prior to the application of M-AMBI; this necessitates dividing an estuary into several sections, which may be classified as different ESs. From this perspective, a novel approach to integrate habitat heterogeneity in a global ES assessment was tested.  相似文献   
935.
In this paper the Marine Fish Community Index (MFCI) for the assessment of ecological status of marine environment is proposed. The MFCI was divided into 4 typologies: Rocky subtidal; shallow, intermediate and deep soft-bottoms. Based on the typical community associated to each typology and the DPSIR analysis performed, a set of metrics were selected and tested through a multiple correlation matrix (Pearson’s coefficient) and the core ones included in the index. The MFCI was applied in all typologies and the scores obtained with each metric were analyzed. In order to test the robustness of the MFCI the final ecological value of each zone was recalculated by removing successively one metric at a time. The MFCI showed a sensitive and robust response in the ecological status assessment. Since it incorporates both functional and structural community information, the MFCI can be useful in the context of the Marine Strategy Framework Directive as well as in other contexts of conservation and sustainable management of the marine environment.  相似文献   
936.
宋茜茜  郑艺  李通  薛磊  张丽 《新疆地质》2019,(1):134-137
利用遥感影像,结合地形、气象及土壤质量等数据,基于综合指数法,分析了2000—2014年则克台堰塞湖地区生态环境质量及其变化情况。结果表明:(1)近15年,则克台堰塞湖地区生态环境质量一般,总体呈下降趋势,生态环境质量下降区域随时间由研究区东北部向西南部迁移;(2)滑坡泥石流等地质灾害为该地区生态环境质量变差的主要原因;(3)该地区生态环境在遭到破坏后,通过自我调节或可在3年内得到明显改善。本文依据则克台堰塞湖地区生态环境背景建立了适用于当地的生态环境质量评价指标体系,为生态环境修复及防灾救灾提供理论依据。  相似文献   
937.
针对工程活动形成的高陡边坡,采用植被混凝土生态防护技术进行治理覆绿效果显著。利用植被混凝土生态防护技术,对植被混凝土基材配方及技术指标进行分析,为施工做准备,明确了施工工艺的步骤及注意事项。通过工程实例分析,突显了此技术较高的应用价值及综合效益。  相似文献   
938.
《China Geology》2019,2(1):1-7
Based on the remote sensing survey and monitoring results of snow lines on the Qinghai-Tibet Plateau, the authors analyzed the following eco-geological factors such as water resources, permafrost, desertification, wetlands, lake, geological disasters, sea-level rising, earthquake, etc., affected by the change of snow lines over the past 40 years, and discuss the response between glacier evolution and the eco-geological environment preliminarily.©2019 China Geology Editorial Office.  相似文献   
939.
长白山哈泥泥炭地7种苔藓分布与环境关系研究   总被引:1,自引:1,他引:0  
在长白山哈泥泥炭地调查7种苔藓的典型生境,共计93个样方,计测样方中苔藓植物的盖度和包括泥炭全氮(TN)、全磷(TP)、K^+和Ca^2+等在内的9个环境因子,应用典范对应分析对数据进行处理,做出样方、物种与环境因子关系二维排序图,排序图直观地反映苔藓植物与环境因子间的关系。结果表明,排序图中同种苔藓为主的样方多数集中分布,个别分散分布;水位埋深、沼泽水pH以及乔木郁闭度和灌木盖度是影响泥炭地苔藓植物生态位分异的主要环境因子,泥炭全磷(TP)对苔藓植物分布影响较大。7种苔藓中,尖叶泥炭藓(Sphagnum capilifolium)、大泥炭藓(S.palustre)在乔木郁闭度和pH梯度上,喙叶泥炭藓(S.fallax)、沼泽皱缩藓(Aulacomnium palustre)在水位埋深和灌木盖度梯度上,生态位分异明显。锈色泥炭藓(S.fuscum)、桧叶金发藓(Polytrichum juniperinum)和中位泥炭藓(S.magellanicum)在各个环境梯度上生态位都比较相似。  相似文献   
940.
Assessing the health of ecosystems has become a focal point among researchers worldwide. Recently, the European Water Framework Directive intensified the development of approaches to assess ecosystems’ ecological quality. The Benthic Assessment Tool (BAT) is a multimetric approach to evaluate condition of subtidal soft bottom macroinvertebrates of coastal and transitional waters. The effects of anthropogenic disturbances on benthic macroinvertebrate communities, from 1990 to 2006, allowed testing BAT performance in Mondego estuary (Portugal). The method was able to detect decrease on ecological quality, induced essentially by eutrophication and physical disturbances, and follow communities’ subsequent recovery. It evidenced, nevertheless, some limitations associated with the unstable nature of estuaries. The ecological classification of key species in the community and the balance expected between ecological groups of estuarine communities had great influence in the final ecological assessment. Shortcomings of the method were discussed in the light of its suitability for assessing transitional waters’ condition.  相似文献   
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