东洞庭湖湿地水鸟群落季节动态格局

为了对东洞庭湖湿地鸟类的继续研究提供数据和理论依据,2005年7月~2006年12月采用样方法和样线法对该湿地水鸟进行了调查,共记录到水鸟89种,并对其季节动态格局进行了研究分析,结果表明,全年水鸟种类和数量均是冬季多,夏季少,特别是数量波动有明显的冬季高峰期和夏季低谷期,季节差异非常显著。     

武汉市湿地主要环境问题及保护对策

武汉市湿地资源丰富,城市的快速发展给这些湿地生态系统带来了诸多威胁,主要表现在：面积萎缩、水质污染加剧、生物多样性下降、可利用水资源减少等方面,提出了加强湿地资源可持续利用和保护的对策措施。     

湿地氮循环过程及其研究进展

从湿地氮循环的主要研究对象和基本研究方法出发,讨论了同位素方法在氮循环研究中的应用,总结了氮同位素用于研究湿地系统的生物地球化学过程以及各形态氮的迁移转化等方面的应用实例,并对湿地氮循环同位素及其相关技术方法的发展趋向进行了展望,最后归纳提出了氮同位素在我国湿地生态系统氮循环研究中的不足及未来的发展方向。     

石首市天鹅洲湿地资源保护与生态旅游开发

湿地是地球上水陆相互作用形成的独特生态系统,是重要的生存环境和自然界最具生物多样性的生态景观之一,具有巨大的生态效益、社会效益和经济效益,也为生态旅游提供了得天独厚的自然条件。以保护湿地资源为前提,结合天鹅洲湿地自然保护区的保护与开发现状,提出了保护与生态旅游开发的策略。     

Humic acids as electron acceptors in wetland decomposition

Decomposition of organic matter in inundated wetland soils requires a number of interdependent microbial processes that ultimately generate CO₂ and CH₄. Largely as the result of anaerobic decomposition, wetland soils store globally significant amounts of organic carbon and are currently net sources of CH₄ to the atmosphere. Given the importance of wetlands in the global carbon cycle, it is important to understand controls on anaerobic decomposition in order to predict feedbacks between wetland soils and global climate change. One perplexing pattern observed in many wetland soils is the high proportion of CO₂ resulting from anaerobic decomposition that cannot be explained by any measured pathway of microbial respiration. Recent studies have hypothesized that humic substances, and in particular solid-phase humic substances in wetland soils, can support anaerobic microbial respiration by acting as organic electron acceptors. Humic substances may thus account for much of the currently unexplained CO₂ measured during decomposition in wetland soils. Here we demonstrate that humic acids extracted from a variety of wetland soils act as either electron donors or electron acceptors and alter the ratio of CO₂:CH₄ produced during anaerobic laboratory incubations. Our results suggest that soil-derived humic substances may play an important, and currently unexplored, role in anaerobic decomposition in wetland soils.     

四川省湿地生态系统服务功能价值评估

依据《中国湿地百科全书》及四川省林业厅调查数据,将四川省湿地类型划分为河流湿地、湖泊湿地、沼泽和沼泽化草地、水田湿地、池塘湿地、水库湿地两大类6种类型,采用定量货币化方法对四川省湿地生态系统服务功能价值进行了估算,为四川省湿地保护与规划提供生态经济理论依据。结果表明,四川省湿地生态服务功能的总价值达7 483.03亿元人民币,相当于四川省2009年GDP的52.88%,各项湿地生态功能价值中最高的是固碳释氧功能价值达3 422.00亿元人民币,约占45.73（,其次是水分调节功能和物质生产功能,说明湿地对四川省的生态环境和国民经济有重要作用,并和人们的生产、生活、娱乐密切相关。     

三江平原挠力河流域湿地垦殖的影响因素

综合利用DEM数据、地貌数据和1954-2000年5个时段的土地利用/覆被数据,分析了该流域近50a 来的湿地垦殖过程及其影响因素,结果发现:2000年的沼泽湿地面积仅为1954年面积的36.7%,而且80%左右的沼泽湿地都开垦为耕地.自然环境要素与农场建设对整个湿地的开垦过程产生了重要影响.分布于不同海拔高度与不同坡...     

大兴安岭主要沼泽湿地土壤碳氮垂直分布特征

为了研究大兴安岭北部两类主要沼泽湿地(柴桦-笃斯越桔和落叶松-杜香)土壤有机碳和全氮的垂直分布特征与积累特征,采用重铬酸钾-外加热法、凯氏定氮仪分别测定了土壤有机碳、全氮质量分数,并用环刀法测定了土壤密度.结果表明:两类湿地剖面有机碳分布均具有明显的储碳层和淀积层;上层的储碳层厚度约为10 cm,有机碳平均质量分数分别...     

Below ground carbon turnover and greenhouse gas exchanges in a sub-arctic wetland

Here we present results from a field experiment in a sub-arctic wetland near Abisko, northern Sweden, where the permafrost is currently disintegrating with significant vegetation changes as a result. During one growing season we investigated the fluxes of CO₂ and CH₄ and how they were affected by ecosystem properties, i.e., composition of species that are currently expanding in the area (Carex rotundata, Eriophorum vaginatum and Eriophorum angustifolium), dissolved CH₄ in the pore water, substrate availability for methane producing bacteria, water table depth, active layer, temperature, etc. We found that the measured gas fluxes over the season ranged between: CH₄ 0.2 and 36.1 mg CH₄ m⁻² h⁻¹, Net Ecosystem Exchange (NEE) −1000 and 1250 mg CO₂ m⁻² h⁻¹ (negative values meaning a sink of atmospheric CO₂) and dark respiration 110 and 1700 mg CO₂ m⁻² h⁻¹. We found that NEE, photosynthetic rate and CH₄ emission were affected by the species composition. Multiple stepwise regressions indicated that the primary explanatory variables for NEE was photosynthetic rate and for respiration and photosynthesis biomass of green leaves. The primary explanatory variables for CH₄ emissions were depth of the water table, concentration of organic acid carbon and biomass of green leaves. The negative correlations between pore water concentration and emission of CH₄ and the concentrations of organic acid, amino acid and carbohydrate carbon indicated that these compounds or their fermentation by-products were substrates for CH₄ formation. Furthermore, calculation of the radiative forcing of the species expanding in the area as a direct result of permafrost degradation and a change in hydrology indicate that the studied mire may act as an increasing source of radiative forcing in future.     

A comparison of constructed and natural habitat for frog conservation in an Australian agricultural landscape

Constructed ponds are an important consideration in the conservation of wetland biota in agricultural landscapes. Twenty-two natural ponds and 22 adjacent constructed ponds (farm dams) were surveyed on the Southern Tablelands of New South Wales to compare patterns of use by frogs and develop frog conservation recommendations. Farm dams supported similar numbers of frog species to natural ponds, although differences in frog assemblage were observed between the pond types. Limnodynastes tasmaniensis and Uperolia laevigata were significantly more likely to occur at farm dams while L. peronii was more likely to occur at natural ponds. Results suggest waterbodies with high levels of emergent vegetation cover that lack fish are likely to support a high number of frog species, regardless of origin (i.e. natural or constructed). However, it is important for landholders to conserve natural waterbodies as these environments appear likely to support frog species that do not use farm dams.