Quantifying the nitrogen retention capacity of natural wetlands in the large-scale drainage basin of the Baltic Sea   总被引：3，自引：0，他引：3  

Jansson  Åsa  Folke  Carl  Langaas  Sindre 《Landscape Ecology》1998,13(4):249-262

We estimate the nitrogen retention capacity of natural wetlands in the 1.7 million km² Baltic Sea drainage basin, using a wetland GIS data base. There are approximately 138,000 km² of wetlands (bogs and fens) in the Baltic Sea drainage basin, corresponding to 8% of the area. The input of nitrogen to natural wetlands from atmospheric deposition was estimated to 55,000–161,000 ton y¹. A map of the deposition of both wet and dry nitrogen is presented. The input from the human population was estimated to 255,000 ton y¹ in terms of excretory release in processed sewage water. There may also be leakage from forests and agricultural land into the wetlands. Due to lack of data on hydrology and topography, such potential nitrogen sources are not accounted for here. The capacity of the wetlands to retain the atmospheric deposition of nitrogen was estimated to 34,000–99,000 ton y¹. The potential retention by wetlands was estimated to 57,000–145,000 ton y¹ when the nitrogen input from the human population was added. If drained wetlands were to be restored and their area added to the present wetland area, the nitrogen retention capacity was estimated to increase to 196,000–261,000 ton y¹. Our results indicate that existing natural wetlands in the Baltic Sea drainage basin annually can retain an amount of nitrogen which corresponds to about 5–13% of annual total (natural and anthropogenic) nitrogen emissions entering the Baltic Sea. The ecosystem retention service performed by wetlands accounts for a substantial nitrogen removal, thereby reducing the eutrophication of the Baltic Sea.  相似文献   

A spatially-explicit method to assess the dry deposition of air pollution by urban forests in the city of Florence,Italy     

《Urban Forestry & Urban Greening》2017

Urban forests (UF) provide a range of important ecosystem services (ES) for human well-being. Relevant ES delivered by UF include urban temperature regulation, runoff mitigation, noise reduction, recreation, and air purification. In this study the potential of air pollution removal by UF in the city of Florence (Italy) was investigated. Two main air pollutants were considered – particulate matter (PM₁₀) and tropospheric ozone (O₃) – with the aim of providing a methodological framework for mapping air pollutant removal by UF and assessing the percent removal of air pollutant.The distribution of UF was mapped by high spatial resolution remote sensing data and classified into seven forest categories. The Leaf Area Index (LAI) was estimated spatially using a regression model between in-field LAI survey and Airborne Laser Scanning data and it was found to be in good linear agreement with estimates from ground-based measurements (R² = 0.88 and RMSE% = 11%). We applied pollution deposition equations by using pollution concentrations measured at urban monitoring stations and then estimated the pollutant removal potential of the UF: annual O₃ and PM₁₀ removal accounted for 77.9 t and 171.3 t, respectively. O₃ and PM₁₀ removal rates by evergreen broadleaves (16.1 and 27.3 g/m²), conifers (10.9 and 28.5 g/m²), and mixed evergreen species (15.8 and 31.7 g/m²) were higher than by deciduous broadleaf stands (4.1 and 10 g/m²). However, deciduous forests exhibited the largest total removal due to the high percentage of tree cover within the city. The present study confirms that UF play an important role in air purification in Mediterranean cities as they can remove monthly up to 5% of O₃ and 13% of PM₁₀.  相似文献   

基层图书馆为弱势群体服务的现状与思考——以徐州地区为例     

方嘉珍 《农业图书情报学刊》2010,22(10):344-346

在分析弱势群体构成和文化需求的基础上,以徐州地区为例论述了基层图书馆为农村弱势群体服务的若干举措和实践活动,探讨为农村弱势群体服务的方式方法,并对今后工作提出具体建议。  相似文献   

林地定额管理系统分析与实现     

何涛  王洪波  付长捷  胡长茹 《林业资源管理》2011,(5)

林地是森林资源的重要组成部分,如何有效地对林地进行管理,对于实现胡锦涛总书记提出的到2020年我国森林面积和蓄积量比2005年分别增加4 000万hm2和13亿m3的林业双增目标具有重要意义。而林地定额管理是林地管理的一个重要组成部分。目前的林地定额管理主要依靠各省人工逐笔核算和月末上报的方式,不仅存在一定的时滞性,而且还可能出现超额使用林地定额情况。针对以上弊端,深入分析和研究林地定额的细分规则,提出一种基于面向服务的体系结构(SOA)架构的林地定额管理系统。不仅解决了时滞性,实现对林地定额的实时管理与监控,而且还能灵活地解决林地定额管理中出现的一些特殊情况。  相似文献   

图书馆信息服务的优化   总被引：1，自引：0，他引：1  

徐进 《农业图书情报学刊》2008,20(7)

图书馆信息服务的优化是维护并促进图书馆事业可持续发展的关键,文献的多元性、文化的多样性以及生存环境的丰富性为其提供了拓展的空间.围绕这一主题进行阐述,分析了全新的信息环境下,拓展和延伸图书馆信息服务的必要性和优化的方式,希望借此对图书馆信息服务的发展有所助益.  相似文献   

对第三方物流企业发展增值服务竞争战略的SWOT分析   总被引：2，自引：0，他引：2  

宋丹  许恒勤 《森林工程》2009,25(2):94-96

自从我国加入WTO后，物流行业的竞争日益激烈，物流业面临着前所未有的挑战。第三方物流企业想要求得发展，必须通过发展增值服务获得更大的市场份额。本文通过SWOT分析法，对我国第三方物流企业发展增值服务的状况进行系统分析，对于如何发展增值服务提出建议，指导企业正确的把握发展方向，抓住机遇，赢得市场空间。  相似文献   

中国饭店业的员工培训理念     

赵科峰 《湖南农机》2009,(2):67-68,79

随着酒店竞争日趋激烈,酒店对员工素质的要求也日益提高。如何提高员工队伍的素质、培养高素质的员工队伍成为困扰酒店的一大难题。而我国酒店员工的培训现状并不令人满意,存在许多问题。因此,要使酒店服务质量提高的同时提高经济效益,必须从根本上采取适当的方式方法改变我国酒店员工培训的现状。  相似文献   

数字环境下的高校图书馆信息资源建设与服务理念   总被引：3，自引：1，他引：2  

黄华  谢一唯  成涛 《农业图书情报学刊》2009,21(2):39-42

论述了数字环境下高校图书馆信息资源建设策略,阐述了高校图书馆基于数字化信息资源的深层用户服务理念。  相似文献   

高校图书馆服务于农村劳动力教育培训研究     

马韬靖  韩菲 《农业网络信息》2009,(3)

本文就高校图书馆教育培训优势,以及如何利用图书馆对农村劳动力教育培训进行研究,旨在为当前农村劳动力素质提高拓展新途径.  相似文献   

上海市稻田耕作制度演变与绿色高质量发展进程     

李金文  曹林奎  曹燕  倪远之  钱晓雍 《华中农业大学学报》2022,41(6):101-110

水稻生产不仅对于保障粮食安全意义重大,同时稻田作为一类特殊的人工湿地,对城市的可持续发展也至关重要。上海稻田耕作制度从20世纪80年代的三熟制转变为两熟制,到2010年代又从两熟制逐渐调整为一熟制。近年来,逐步形成了用地与养地相结合的耕作制度,部分地区成功探索了稻田种养结合的绿色生产模式,并逐步实现了品牌化生产。然而,上海水稻绿色生产也面临诸多挑战,包括粮食稳产压力、资源与环境约束以及高度依赖财政补贴、自身盈利能力不足等。针对上述问题,本文提出了今后稻田耕作制度绿色、高质量发展的对策：在确保耕地面积、稻田比例不下降与稳定单产潜力的基础上,稳定全市粮食产量;创新和集成绿色栽培技术,提升稻田湿地生态功能;深化稻米品牌建设,以品牌化实现生态产品价值,提升水稻绿色种植经济效益。  相似文献