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1.
Abstract: Coffee farms can support significant biodiversity, yet intensification of farming practices is degrading agricultural habitats and compromising ecosystem services such as biological pest control. The coffee berry borer (Hypothenemus hampei) is the world's primary coffee pest. Researchers have demonstrated that birds reduce insect abundance on coffee farms but have not documented avian control of the berry borer or quantified avian benefits to crop yield or farm income. We conducted a bird‐exclosure experiment on coffee farms in the Blue Mountains, Jamaica, to measure avian pest control of berry borers, identify potential predator species, associate predator abundance and borer reductions with vegetation complexity, and quantify resulting increases in coffee yield. Coffee plants excluded from foraging birds had significantly higher borer infestation, more borer broods, and greater berry damage than control plants. We identified 17 potential predator species (73% were wintering Neotropical migrants), and 3 primary species composed 67% of migrant detections. Average relative bird abundance and diversity and relative resident predator abundance increased with greater shade‐tree cover. Although migrant predators overall did not respond to vegetation complexity variables, the 3 primary species increased with proximity to noncoffee habitat patches. Lower infestation on control plants was correlated with higher total bird abundance, but not with predator abundance or vegetation complexity. Infestation of fruit was 1–14% lower on control plants, resulting in a greater quantity of saleable fruits that had a market value of US$44–$105/ha in 2005/2006. Landscape heterogeneity in this region may allow mobile predators to provide pest control broadly, despite localized farming intensities. These results provide the first evidence that birds control coffee berry borers and thus increase coffee yield and farm income, a potentially important conservation incentive for producers.  相似文献   
2.
生态系统服务功能及其价值核算   总被引:20,自引:4,他引:16  
生态系统服务功能是指生态系统服务与生态系统功能的综合,指生态系统与生态过程所形成及所维持的人类赖以生存的自然环境条件与效用,生态系统服务功能对于人类生存发展具有重要的价值,应该在社会经济体系中得以体现,本文探讨了生态系统服务功能的类型,价值核算方法与理论及其应用研究在完善国民经济核算体系、促进可持续发展等方面的重要意义,并对今后发展进行了展望。  相似文献   
3.
In recent years flows of foreign direct investment (FDI) to developing countries have rapidly been increasing. It is now an important contributor to the national economy and urban growth in scores of developing countries. Rapid urbanization in these countries is leading to many problems in the cities. Existing urban infrastructure and municipal services have been unable to cope with the increased demand arising from growing population and rapid economic growth. Consequently, the environment in these cities has deteriorated alarmingly. This paper assesses the role of FDI in urban environmental management (UEM) by analyzing the linkages between them for Hanoi City in Vietnam. The paper's analysis and findings are presented under three main themes: one, FDI, employment and income; two, FDI and environmental degradation; and three, potential of utilizing FDI for the provision of urban environmental infrastructure and services (UEI&S) in order to improve the urban environment. Both primary and secondary source data have been used. Policy implications of the research findings are drawn from the perspective of sustainable development.  相似文献   
4.
Dick B 《Disasters》1985,9(4):259-269
Although there have been a number of recent developments in our understanding of refugee health problems that have influenced policies and action, the effects of refugees on the health status and services of host communities remain relatively neglected. This article sets out to explain why this is an important issue with implications for policy, planning surveillance and evaluation, training and research.
The first sections outline some of the problems facing host governments and communities in Africa and discuss the changing rhetoric between the first and second International Conferences for Assistance to Refugees in Africa. A number of possible ways in which refugees could affect the individual, agent and environmental causes of disease are considered, as are the characteristics of the refugees, the host communities and the response which may all modify this impact.
Policy implications of the impact of the refugees, both negative and positive, are discussed, and detailed consideration is given to the pros and cons of integrated and parallel approaches to health care provision. The need to monitor carefully the health status and services of host communities is emphasized and recommendations are made for this and other essential developments relating to training and research.  相似文献   
5.
湿地作为水体与陆地之间的过渡地带,具有独特的生态环境特性,是氮循环反应的关键区域.研究湿地生态系统中的全程氨氧化过程(complete ammonia oxidation,comammox),解析该区域中comammox细菌的分布与群落结构特征,补充了此前该新型氨氧化微生物在湿地生态系统中分布特征的研究空白,对于完善comammox细菌在各种不同生态系统中分布情况的研究具有重要意义.本研究在石臼漾人工湿地中于冬夏两季分别采集了大沟中心、大沟边缘、小沟中心和小沟边缘的表层沉积物样品,利用PCR、荧光定量PCR和amoA功能基因高通量测序等方法,解析人工湿地中comammox细菌的时空分布与群落结构特征.主要研究结果如下:①所有样品中均检测到了comammox细菌,其丰度为1.77×105~4.07×107 copies·g-1.冬季,comammox细菌丰度在大沟中高于氨氧化细菌(ammonia oxidizing bacteria,AOB)和氨氧化古菌(ammonia oxidizing archaea,AOA),在小沟中高于AOB,但低于AOA;夏季,comammox细菌丰度在所有样点中均高于AOB和AOA.②冬夏两季样品中,comammox细菌丰度与底物NH4+-N浓度均呈负相关关系,且夏季样品中呈显著性负相关.③主坐标分析(Principle Coordinate Analysis,PCoA)与多样性分析结果表明,comammox细菌群落结构具有空间异质性,且冬季物种多样性高于夏季.  相似文献   
6.
Plants constitute a major element of constructed wetlands(CWs).In this study,a coupled system comprising an integrated vertical flow CW(IVCW) and a microbial fuel cell(MFC) for swine wastewater tre atment was developed to research the effects of macrophytes commonly employed in CWs,Canna indica,Acorus calamus,and Ipomoea aquatica,on decontamination and electricity production in the system.Because of the different root types and amounts of oxygen released by the roots,the rates of chemical oxygen demand(COD) and ammonium nitrogen(NH_4~+-N) removal from the swine wastewater differed as well.In the unplanted,Canna indica,Acorus calamus,and Ipomoea aquatica systems,the COD removal rates were 80.20%,88.07%,84.70%,and 82.20%,respectively,and the NH_4~+-N removal rates were 49.96%,75.02%,70.25%,and 68.47%,respectively.The decontamination capability of the Canna indica system was better than those of the other systems.The average output voltages were 520±42,715±20,660±27,and 752±26 mV for the unplanted,Canna indica,Acorus calamus,and Ipomoea aquatica systems,respectively,and the maximum power densities were 0.2230,0.4136,0.3614,and0.4964 W/m~3,respectively.Ipomoea aquatica had the largest effect on bioelectricity generation promotion.In addition,electrochemically active bacteria,Geobacter and Desulfuromonas,were detected in the anodic biofilm by high-throughput sequencing analysis,and Comamonas(Proteobacteria),which is widely found in MFCs,was also detected in the anodic biofilm.These results confirmed the important role of plants in IVCW-MFCs.  相似文献   
7.
分析生态系统质量与服务现状及变化特征,有助于准确了解流域生态系统状况与趋势,为流域生态保护与修复的高效管理提供参考依据.采用相对生物量密度与相对植被覆盖度指数以及生态系统服务(土壤保持、防风固沙、洪水调蓄、粮食生产)评估模型,评估2000—2015年长江流域生态系统质量及服务变化特征.结果表明:①2000—2015年,长江流域森林、灌丛以及草地生态系统质量提升显著,56.56%的森林、45.65%的灌丛以及19.26%的草地生态系统质量得到不同程度的提高.②研究期间,长江流域粮食生产、洪水调蓄、土壤保持、防风固沙均呈显著上升趋势,其中粮食生产能力增加13.7%,洪水调蓄功能提升10.1%,土壤保持服务提高19.5%,防风固沙总量增加30.0%.③长江流域生态系统质量不高,处于低与差质量等级的生态系统面积比例在25%~35%之间;受不同类型的自然和人类活动影响,长江流域生态系统质量与服务均存在局部退化现象.研究显示,在生态质量与服务评估的基础上,分区域、分类型实施不同的生态系统保护与恢复途径,是今后长江流域加强生态系统管理的重要途径.   相似文献   
8.
国土生态修复是我国土地整治战略发展的需求,其空间分区与管控是实施国土整治与生态修复差别化建设的前提条件。以广西各县市为研究单元,在测算和分析生态系统服务供给量和需求量基础上,利用象限匹配法、双变量局部空间自相关和供需协调度来定量分析生态系统服务供需匹配关系、空间聚集程度和协调关联性,进而探讨和划分广西国土生态修复的空间分区及其管控措施与建议。研究表明:(1)广西各县市生态系统服务供给和需求差异明显。环绕广西的四周山林地和重点生态功能区县生态系统服务供给量较高,大中城市区则较低。生态系统服务需求量自东南向西北逐渐减少。(2)广西生态系统服务供需空间匹配呈现高供高需型、低供高需型、低供低需型、高供低需型四种类型,供需局部空间自相关以高-低或低-高的空间聚集为主,且生态系统服务供需协调度平均值为0.531,处于一般均衡。(3)结合生态系统服务供需匹配四类特征和广西地理环境条件,将广西各县域划分为10个分区,并针对各分区提出差异化整治措施和建议。总体上,生态系统服务高供高需型的区域应以保育为主、培育为辅,防止过度开发;高供低需型的区域以保护为主,提高管理水平;低供高需型的区域应以综合改良为主,提高土地效益;低供低需型的区域应以国土生态重构或重建为主,侧重恢复生态系统。  相似文献   
9.
永定河上游流域水生态系统服务价值评估   总被引:4,自引:0,他引:4  
张家口市是首都的水源涵养区和生态功能支撑区,流经该区域的永定河上游流域发挥着保育水资源的重要作用。为全面认识永定河上游流域水资源生态价值,对流域水生态各项服务功能开展定量评价。以2017年为基准年,综合采用InVEST模型与市场价值法系统评估研究区的水源供给量,以空间和货币的手段直观地表达该地区的水源供给情况;对于空间数据较难获取的地区,采用当量因子法评估水土保持与生物多样性价值;采用分摊法计算水生态旅游价值。结果表明:其总价值量为55.14亿元,约占张家口市各区县平均GDP(81.87亿元)的67.35%。其中,水源供给价值、水力发电价值、水产品生产价值、休闲娱乐价值等直接使用价值为28.64亿元,土壤保持、河流输沙、生物多样性等间接使用价值为26.50亿元,水源供给、休闲娱乐和水土保持功能对研究区域水生态系统价值提升和发展具有重要作用。研究区单位面积的生态价值和经济效益分别为0.35亿元和0.23亿元,生态价值远高于经济效益。本文因地制宜的综合评价方法提升了价值评估的科学性和可靠性,对于基础数据较为缺乏的地区,有一定的参考意义。  相似文献   
10.
充分利用自然保护区的旅游资源优势发展旅游业,但不合理的开发会使生态环境遭到破坏、生物多样性逐渐丧失、湿地水质面临污染等等。在分析腾冲北海湿地自然保护区发展生态旅游的基础上对旅游开发中存在的问题提出对策和建议。  相似文献   
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