桂林会仙岩溶湿地健康评价与补偿机制研究

以桂林会仙岩溶湿地为研究对象,应用"压力—状态—响应"模型构建会仙岩溶湿地生态系统健康评价指标体系,利用单因子评价和综合评价方法评价桂林会仙湿地的生态健康指数。评价结果表明:湿地健康状况较差,CEI=0.364;影响会仙湿地生态系统健康的因素主要有年降水量、常年积水面积、农业生产因素等。针对以上影响因素,提出了会仙湿地生态恢复和补偿建议,目标是促进会仙湿地生态系统健康可持续发展。     

洪湖湿地水生植被恢复技术要点

水生植被作为水生态系统的重要组成部分,具有净化水质、消减风浪、景观美化、提供水生生物栖息空间等多种功能。水生植被恢复是湖泊水生态保护与修复的关键环节。洪湖湿地是国际重要湿地,发挥着重要的生态功能,由于近半个世纪过度开展围网养殖等不合理的开发利用,水生植被大幅减少,降低了湖泊的自净能力,水生态系统遭到破坏。近几年,洪湖持续开展生态修复与保护工作,水生植被有所增加。因此,以洪湖水生植被现状为出发点,从植被恢复方式、植物选择、群落配置、维护管理等方面提出洪湖湿地水生植被恢复要点。     

氮磷输入对湿地生态系统碳蓄积的影响

湿地生态系统在全球碳循环中有着举足轻重的作用。由于湿地垦殖、农业化施用等人类活动和全球变暖、大气氮沉降的增多等自然因素的综合作用,大量氮磷营养物质进入湿地,这必将对湿地生态系统碳蓄积产生影响。本文综述了外源氮磷输入对湿地土壤碳库、植被碳库和枯落物分解的影响以及湿地生态系统碳循环的模型研究,并对以后发展趋势进行了预测。     

陆地生态系统碳收支及其主要影响因素分析

CO2的增加是导致全球气温增加的主要因素之一。本文针对陆地生态系统是全球的3大碳库之一,分析了碳在森林、草地、湿地以及农田等陆地生态系统中的收支,并重点评价了碳在不同陆地生态系统中的积累部位和积累量;同时详细分析了影响不同陆地生态系统释放碳的因素,最后提出了增加陆地生态系统对CO2截存和减少CO2排放的措施。     

我国湿地生态系统健康评价研究进展

湿地生态系统的健康评价对湿地的保护、规划管理有着极其重要的作用。根据《湿地公约》的分类,我国湿地类型多样,本文从天然湿地和人工湿地两种湿地类型综述了我国现有的湿地生态系统健康评价研究,阐述了不同类型湿地生态系统的作用,指出了现有湿地生态系统健康评价研究的不足。     

RS与GIS支持的洪湖湿地景观格局分析

利用3S技术对洪湖湿地结构类型进行监测及对洪湖湿地景观格局进行定量分析结果表明,洪湖湿地景观类型所占比例有一定差异,景观多样性指数和均匀度指数较低,景观为少数湿地类型所控制,破碎度指数较小,且景观受人为干扰程度不十分严重,但也不容乐观。     

陆地生态系统稳定性空间格局及影响机制研究综述

稳定性是生态系统保持或恢复自身结构和功能的能力,是维持生态系统服务功能的关键。近年来全球植被稳定性面临重大威胁,生态系统稳定性的研究逐步成为生态学的热点问题。本文综述了稳定性的定义、空间格局及其影响机制,指出了当前研究存在的问题,并对未来发展提出展望。目前研究发现,生态系统稳定性是一个多维结构,主要包括抵抗力、恢复力和时间稳定性三个方面。稳定性及其影响机制具有很强的空间异质性与尺度依赖性,主要表现为在站点尺度由生物多样性等生物因素控制,而在区域及全球尺度则由温度、降水、辐射等非生物因素控制。目前植被稳定性的研究中尚存在数据源噪声难以去除,量化方法未标准化等问题。未来稳定性的研究可逐步由站点等局部尺度向区域、大陆等全局尺度扩展,并形成标准化的稳定性评估方法。     

湿地生态评价指标体系

介绍了湿地的定义及其在保护生物多样性,维持区域生态平衡等方面具有的重要意义;借鉴有关区域生态系统评价的理论,选取多样性,代表性,稀有性,自然性,稳定性入人类威胁等指标并进行分级化处理,提出,制定了一套湿地生态评价指标体系。     

辽宁省河湖湿地生态系统健康评价与管理对策研究

利用综合评价法和多指标评价体系,评价辽宁省重点河湖湿地生态系统健康状况.结果显示,大麦科湿地、三岔河湿地处于健康状态,仙子湖、卧龙湖、獾子洞和阜新阿尔乡湿地处于亚健康状态.针对各河湖湿地生态系统存在的主要问题提出行之有效的管理对策,旨在为河湖湿地生态保护提供一定的参考.     

我国湿地碳循环的研究进展

湿地生态系统的碳循环正成为全球变化与陆地生态系统碳循环研究中的一大热点,在稳定全球气候变化中占有重要地位,其重要性主要表现在湿地土壤是陆地重要的有机碳库,土壤碳密度高,能够相对长期地储存碳,是多种温室气体的源和汇。目前湿地碳循环的研究主要集中在碳循环的影响因素方面,对我国湿地土壤有机碳储存的变化及其空间分布规律的特点研究较少。本文通过文献综述,研究我国不同气候区湿地土壤有机碳的储存变化及空间分布规律,对于了解湿地土壤有机碳的储存特点及其与陆地生态系统碳循环的关系,评价和保护湿地生态系统都具有重要的科学意义。     

洞庭湖区湿地景观变化分析

洞庭湖湿地是我国最重要湿地系统之一,具有多方面功能和价值,主要由河流、湖泊、水田、沼泽、滩地、库塘等几种类型组成。本文利用1980年、1990年、2000年3个时段的Landsat MSS和TM影像及GIS技术对洞庭湖区湿地景观变化进行研究。结果表明,洞庭湖区湿地总面积呈减少趋势,人工湿地面积有所增加,自然湿地面积减少,其中湖泊面积减少最多。这是人类和自然共同作用的结果,其中人类对湿地的改造是导致变化的主要原因,但洞庭湖的泥沙淤积是湖泊面积减少的根本原因。湿地景观的改变导致该区生态环境质量下降,生态功能退化。     

洞庭湖区湿地退化现状及保护对策

洞庭湖湿地是我国重要的淡水湖泊湿地之一,其生态环境对调蓄洪水、调节气候、涵养水源、净化水质、维护生物多样性等方面具有重要的作用。多年来由于人类不合理的开发利用,给湿地生态系统带来了负面影响,致使湿地严重退化。在分析洞庭湖区湿地退化现状及其原因的基础之上,提出了湿地保护与可持续利用的对策和措施。     

The hydrological impacts and sustainability of wetland drainage cultivation in Illubabor,Ethiopia

Wetlands are critical resources in the highlands of southwest Ethiopia, where they perform numerous environmental functions and provide a range of benefits for local communities. In recent years, however, an increase in the drainage and cultivation of these areas and reports of wetland degradation have raised concerns over the sustainability of wetland agriculture. This paper presents the results of a study in which groundwater levels were monitored in a series of wetlands undergoing different stages of drainage and cultivation, to establish the hydrological changes taking place as a consequence. The results suggest that drainage and cultivation induce extreme spatial and temporal variations in the wetland watertable. This is linked in part to structural and chemical changes in the wetland soil which affect hydraulic conductivity. Statistical analysis of this variability revealed the existence of wetland subunits, exhibiting specific hydrological behaviour, which may reflect the influence of current and past land use. Although degradation of these wetlands does occur, many wetland users are aware of their impacts and have developed practices which, in most cases, prevent overdrainage to the extent that the wetlands cannot support agriculture. In this respect, it is argued that wetland use remains hydrologically sustainable, although this ultimately rests upon the ability of communities to continue to develop and apply their indigenous wetland management practices under rapidly changing environmental, socio‐economic and political conditions. Copyright © 2002 John Wiley & Sons, Ltd.     

Landscape-level processes and wetland conservation in the Southern Appalachian Mountains

The function of wetland ecosystems is not independent of the landscapes in which they are embedded. They have strong physical and biotic linkages to the surrounding landscape. Therefore, incorporating a broad-scale perspective in our study of wetland ecology will promote our understanding of these habitats in the Southern Appalachians. Changes in the surrounding landscape will likely affect wetlands. Broad-scale changes that are likely to affect wetlands include: 1) climate change, 2) land use and land cover change, 3) water and air-borne pollution, 4) a shift in disturbance/recovery regimes, and 5) habitat loss and fragmentation. Changes in climate and land cover can affect the hydrology of the landscape and, therefore, the water balance of wetlands. Excessive nutrients and toxin transported by air and water to wetlands can disrupt natural patterns of nutrient cycling. Periodic disturbances, like flooding in riparian zones, is required to maintain some wetlands. A change in disturbance regimes, such as an increase in fire frequency, could alter species composition and nutrient cycles in certain wetlands. Many plant and animal species that found in small, isolated wetlands have populations that are dependent on complementary habitats found in the surrounding landscape. Loss or fragmentation of these complementary habitats could result in the collapse of wetland populations.     

Responses of nitrogen cycling and related microorganisms to brackish wetlands formed by evapotranspiration

Elevated evapotranspiration due to warmer air temperature could raise salinity and nutrient levels of some inland wetlands, potentially impacting nitrogen cycling. To characterize the impact of high evapotranspiration on soil microbial nitrogen cycling in inland wetlands, we compared freshwater and brackish marsh(or non-marsh) wetlands in terms of sediment ammonia-oxidizing rate(AOR), denitrifying rate(DR), and related microbial communities in a typical inland basin, the Hulun Lake basin, in Chi...     

鄱阳湖典型洲滩湿地土壤环境因子对植被分布影响研究

湿地植被生长的影响因素包括非生物因素和生物因素两部分。其中,非生物因素中对湿地植被格局影响较大的主要是水文和土壤环境因子,也是当今湿地生态水文过程研究的热点和重点。通过研究鄱阳湖典型洲滩湿地4种植物群落带下各土壤环境因子的含量变化特征,结合研究区20个植被样方的典范对应分析(Canonical Correspondence Analysis,CCA)排序,分析了鄱阳湖典型洲滩湿地主要土壤环境因子及其对植被分布的影响。结果表明:不同植被群落下的全氮含量有明显差异,依次为苔草带藜蒿-狗牙根带芦苇-苔草带苔草-虉草带;总有机碳与全氮含量大小在不同植被群落带的分异趋势相同,二者存在极显著相关关系;土壤全磷含量随植被群落不同的变化规律不明显;随植被群落带离湖泊水体距离逐渐减小,土壤中速效钾含量有增大的趋势,但程度较小。鄱阳湖典型洲滩湿地土壤有机碳与全氮、有效磷呈极显著相关关系,土壤含水量与土壤有效磷呈显著负相关关系,有效磷与全氮呈极显著相关关系。土壤含水量是影响鄱阳湖湿地研究区植被分布的最主要因素,土壤pH、全钾含量也是影响湿地植被分布的重要土壤环境因子。     

东居延海生态系统服务功能价值的能值分析

在了解东居延海湿地功能结构特征的基础上,根据生态学基础理论,将湿地生态系统服务功能划分为社会—经济—生态3个方面,结合湿地功能表现效果,运用能值分析方法,建立并量化湿地功能价值指标评价体系,定量分析了各功能价值的能值。研究结果表明:东居延海湿地总价值为1.56×1020sej,其中社会价值2.41×1019sej、经济价值2.68×1019sej、生态价值1.04×1020sej,湿地能值货币价值为2.12亿元,单位面积湿地价值为453.86万元/km2,是青海湖湿地价值的1.16倍。东居延海的存在对额济纳旗地区生态环境的恢复及改善西北地区盐碱化和荒漠化等生态问题具有重大意义。     

Wetland Simulation Model for Nitrogen, Phosphorus, and Sediments Retention in Constructed Wetlands

Steamboat Creek, Washoe County, Nevada, is considered the most polluted tributary of the Truckee River, therefore the reduction of nutrients from the creek is an important factor in reducing eutrophication in the lower Truckee River. Restoration of the wetlands along the creek has been proposed as one method to improve water quality by reducing nutrient and sediments from non-point sources. This study was aimed to design a simulation model wetlands water quality model (WWQM) that evaluates nitrogen, phosphorus, and sediments retention from a constructed wetland system. WWQM is divided into four submodels: hydrological, nitrogen, phosphorus, and sediment. WWQM is virtual Visual Basic 6.0 program that calculates hydrologic parameters, nutrients, and sediments based on available data, simple assumptions, knowledge of the wetland system, and literature data. WWQM calibration and performance was evaluated using data sets obtained from the pilot-scale constructed wetland over a period of four and half years. The pilot-scale wetland was constructed to quantify the ability of the proposed wetland system for nutrient and sediment removal. WWQM simulates nutrient and sediments retention reasonably well and agrees with the observed values from the pilot-scale wetland system. The model predicts that wetlands along the creek will remove nitrogen, phosphorus, and sediments by 62, 38, and 84 %, respectively, which would help to reduce eutrophication in the lower Truckee River.