Evaluating the sensitivity of wetlands to climate change with remote sensing techniques   总被引：1，自引：0，他引：1       下载免费PDF全文

Zutao Ouyang  Richard Becker  Wade Shaver  Jiquan Chen 《水文研究》2014,28(4):1703-1712

Wetlands are valuable ecosystems that provide many valuable services, yet many of these important ecosystems are at risk because of current trends in climate change. The Prairie Pothole Region (PPR) in the upper‐midwest of the United States and south‐central Canada, characterized by glacially sculpted landscapes and abundant wetlands, is one such vulnerable region. According to regional/global climate model predictions, drought occurrence will increase in the PPR region through the 21st century and thus will probably cause the amount of water in wetlands to decline. Water surface area (WSA) of Kidder County, ND, from 1984–2011 was measured by classifying TM/ETM+(Landsat Thematic Mapper / Enhanced Thematic Mapper Plus) images through the modified normalized difference water index. We then developed a linear model based on the WSA of these wetlands and historical climate data and used this to determine the wetland sensitivity to climate change and predict future wetlands WSA in the PPR. Our model based on Palmer drought severity index (PDSI) of the current year (PDSI_{t ? 0}) and of the previous two years (PDSI_{t ? 2}) can explain 79% of the annual wetland WSA variance, suggesting a high sensitivity of wetlands to drought/climate change. We also predicted the PPR wetlands WSA in the 21st century under A1B scenario (a mid‐carbon emission scenario) using simulated PDSI based on Intergovernmental Panel on Climate Change AR4 22‐model ensemble climate. According to our prediction, the WSA of the PPR wetlands will decrease to less than half of the baseline WSA (defined as the mean wetlands WSA of the 2000s) by the mid of the 21st century, and to less than one‐third by the 2080s, and will then slightly increase in the 2090s. This considerable future wetland loss caused only by climate change provides important implication to future wetland management and climate adaptation policy. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

The role of biogenic structures on the biogeochemical functioning of mangrove constructed wetlands sediments - A mesocosm approach     

Gil Penha-Lopes  Erik Kristensen  Perrine Mangion  José Paula 《Marine pollution bulletin》2010,60(4):560-572

Benthic metabolism (measured as CO₂ production) and carbon oxidation pathways were evaluated in 4 mangrove mesocosms subjected daily to seawater or 60% sewage in the absence or presence of mangrove trees and biogenic structures (pneumatophores and crab burrows). Total CO₂ emission from darkened sediments devoid of biogenic structures at pristine conditions was comparable during inundation (immersion) and air exposure (emersion), although increased 2-7 times in sewage contaminated mesocosms. Biogenic structures increased low tide carbon gas emissions at contaminated (30%) and particularly pristine conditions (60%). When sewage was loaded into the mesocosms under unvegetated and planted conditions, iron reduction was substituted by sulfate reduction and contribution of aerobic respiration to total metabolism remained above 50%. Our results clearly show impacts of sewage on the partitioning of electron acceptors in mangrove sediment and confirm the importance of biogenic structures for biogeochemical functioning but also on greenhouse gases emission.  相似文献   

兰州银滩湿地区域生态经济价值评估   总被引：2，自引：2，他引：0  

王致萍  林栋 《中国沙漠》2008,28(2):322-325

通过分析人工湿地的生态系统服务功能,阐述了黄河湿地生物多样性保护与水文调控生态功能区的重要性,计算了兰州银滩湿地的固碳释氧、空气质量调节、水源涵养和科研文化四项核心生态经济价值。结果表明：银滩湿地核心生态经济价值理论值为1 623.7万元,其中固碳释氧和科研文化价值实现率较高,分别为324.88万元和11.53万元。但现状水分供给、生态结构方面尚存在不合理之处,通过合理配置树草种构成,优化引水渠道等措施,该湿地将发挥更大的生态经济效益。  相似文献   

珠江口红树林湿地演变的遥感分析   总被引：29，自引：0，他引：29  

黎夏  刘凯  王树功 《地理学报》2006,61(1):26-34

广东拥有全国面积最大的红树林湿地。但近年来经济的快速发展使得该湿地系统发生了很大的变化。利用多时相的遥感图像和专家系统方法对珠江口红树林湿地的时空变化进行了分析。结合雷达遥感图像,对红树林群落分类及生物量估算进行了研究,改善了单独使用光学遥感的不足。获得了试验区红树林的变化趋势、类型分布及生物量等情况,为红树林湿地的生态保护提供了重要信息和新的监测手段。  相似文献