Hydrological drivers of wetland vegetation community distribution within Everglades National Park,Florida   总被引：1，自引：0，他引：1  

M. Jason Todd  R. Muneepeerakul  D. Pumo  S. Azaele  F. Miralles-Wilhelm  A. Rinaldo  I. Rodriguez-Iturbe 《Advances in water resources》2010

The influence of hydrological dynamics on vegetation distribution and the structuring of wetland environments is of growing interest as wetlands are modified by human action and the increasing threat from climate change. Hydrological properties have long been considered a driving force in structuring wetland communities. We link hydrological dynamics with vegetation distribution across Everglades National Park (ENP) using two publicly available datasets to study the probability structure of the frequency, duration, and depth of inundation events along with their relationship to vegetation distribution. This study is among the first to show hydrologic structuring of vegetation communities at wide spatial and temporal scales, as results indicate that the percentage of time a location is inundated and its mean depth are the principal structuring variables to which individual communities respond. For example, sawgrass, the most abundant vegetation type within the ENP, is found across a wide range of time inundated percentages and mean depths. Meanwhile, other communities like pine savanna or red mangrove scrub are more restricted in their distribution and found disproportionately at particular depths and inundations. These results, along with the probabilistic structure of hydropatterns, potentially allow for the evaluation of climate change impacts on wetland vegetation community structure and distribution.  相似文献   

广西湿地资源现状与保护对策   总被引：3，自引：1，他引：2  

李桂荣  梁士楚 《湿地科学与管理》2008,4(1):40-43

本文分析了近年来广西湿地生境、类型、野生动植物资源、水资源保护与可持续利用等方面的现状,并指出了存在的问题及今后的保护对策。  相似文献   

Long-term differences in annual litter production between alien (Sonneratia apetala) and native (Kandelia obovata) mangrove species in Futian,Shenzhen, China     

Lina Liu  Fenglan Li  Qiong Yang  Nora F.Y. Tam  Wenbo Liao  Qijie Zan 《Marine pollution bulletin》2014

Annual litter production in alien (Sonneratia apetala) and native (Kandelia obovata) mangrove forests in Shenzhen, China were compared from 1999 to 2010. S. apetala had significantly higher litter production than K. obovata, with mean annual total litter of 18.1 t ha⁻¹ yr⁻¹ and 15.2 t ha⁻¹ yr⁻¹, respectively. The higher litter production in S. apetala forest indicates higher productivity and consequently more nutrient supply to the estuarine ecosystems but may be more invasive due to positive plant-soil feedbacks and nutrient availability to this alien species. Two peaks were recorded in S. apetala (May and October), while only one peak was observed in K. obovata, in early spring (March and April). Leaf and reproductive materials were the main contributors to litter production (>80%) in both forests. These results suggest that the ecological function of S. apetala and its invasive potential can be better understood based on a long-term litter fall analysis.  相似文献   

基于越冬水鸟生境模拟的拟建鄱阳湖水利枢纽生态控制水位探讨   总被引：1，自引：0，他引：1  

陈炼钢  陈黎明  徐祎凡  贾建伟  栾震宇  施勇  金秋  胡腾飞 《湖泊科学》2020,32(5):1519-1528

长江及鄱阳湖水系上游水库群运用后鄱阳湖枯季水文节律出现新的变化,为应对新的枯水情势,鄱阳湖水利枢纽作为一个选项被提出,如何确定其适宜的调控水位才能维持鄱阳湖湿地生态系统健康是其中的重点与难点.本文选择鹤类、小天鹅、鸿雁等食植物块茎水鸟作为鄱阳湖湿地生态系统的指示物种,基于EFDC水动力学模型和生境适宜度曲线构建了鄱阳湖越冬水鸟生境数值模拟模型;从食物资源与取食可及性两个方面,分苦草(Vallisneria natans)生长期和水鸟越冬期两个时段,以水深作为关键生境因子,对近10年鄱阳湖苦草及水鸟取食潜在生境面积变化进行了连续模拟;揭示了鄱阳湖苦草及水鸟取食潜在生境面积随水位的变化规律并构建了定量响应函数:苦草潜在生境面积随水位呈单峰型变化,在星子站水位为14.8 m时达到最大,约为1703 km2;越冬水鸟取食潜在生境面积随水位呈三段式变化,最大和最小面积分别约为564和476 km2,相应星子站水位分别为11.73和9.56 m.在此基础上,针对拟建的鄱阳湖水利枢纽工程,基于不同调度分期内生境保护目标的差异确定了符合天然水位波动特征的生态水位动态调控方案:下闸蓄水期内水位宜控制在16 m以下,后续根据越冬水鸟迁入情况逐步下降以增加取食生境面积,在12月次年1月的越冬水鸟数量峰值期水位宜控制在12.5 m以下,后续根据来水情况逐步过渡至江湖连通期的自然状态.成果从保护越冬水鸟食物资源与取食可及性两个方面提出了鄱阳湖水利枢纽生态水位的动态调控阈值,为江湖新水沙条件下鄱阳湖湿地生态系统保育提供了量化依据.  相似文献   

Identifying environmental drivers of chlorophyll-a dynamics in Austral subtropical ephemeral ecosystems     

《Limnologica》2019

Environmental and biological features of Austral subtropical pan types were assessed, along with the drivers of chlorophyll-a (chl-a) concentrations. Chl-a biomass varied considerably across seasons and endorheic pans had elevated chl-a concentrations compared to floodplain pans. The major driver of chl-a concentration based on generalised linear/non-linear models (GLZ) was total phosphorous and total suspended solids for all pan types and seasons combined. These results are discussed within the context of secondary productivity, aquatic ecosystem heterogeneity and endorheic pan conservation.  相似文献   

中国湿地生态恢复评价标准制定探讨     

崔芳 《湿地科学与管理》2015,11(2):62-65

在概述国内外湿地生态恢复研究概况的基础上,探讨了湿地生态恢复标准的制定方法。在评价标准的制定上,试图综合考虑湿地恢复的生态结构和功能、生态环境、生物种群、景观恢复及资源稀缺性价值和基础设施建设、管理等方面的内容和关系,并尽可能选取一般性的评估指标来满足多数湿地的评价需要。在特定条件下的湿地恢复评价需要增加某些特殊性的评估指标,通过赋予不同限制性因子权重,在综合以上多方面评价结果的基础上,通过划分评价等级最终给出评价结果。对今后的研究方向进行了展望,并提出了研究重点。  相似文献   

Remote sensing-based dynamic monitoring and environmental change of wetlands in southern Mongolian Plateau in 2000–2018     

《China Geology》2021,4(2):353-363

The environmental change in the wetlands in the southern Mongolian Plateau has important impacts on the environment of North China and even the entire Northeast Asia, from which the global climate change can be understood on a large scale, especially the climate change in the Mongolian Plateau. This study extracted the information on the wetlands from three stages of remote sensing images (also referred to as RS images) of the study area, including Enhanced Thematic Mapper Plus (ETM+) images of 2000, TM images of 2010, and Landsat 8 Operational Land Imager (OLI) images of 2018. As indicated by the extraction results, the area of wetlands decreased from 796.90 km² of 2000 to 666.24 km² of 2018 at a rate of 7.26 km²/a. The reduced area is 130.66 km², which is about 16.4% reduction. And the patch number of wetlands decreased from 731 of 2000 to 316 of 2018 in the study area, approximately 56.8% reduction (415 patches), and the decrease in the area of the wetlands mainly occurred in the northwest endorheic region. In terms of wetland types, the change of the wetlands was dominated by the decrease of lacustrine wetlands, of which the area and patch number decreased by 106.2 km² and 242, respectively. Furthermore, the area of the lacustrine wetlands decreased at the highest rate of 8.70 km²/a in 2010–2018. From the perspective of spatial distribution, the wetlands in the western part shrunk more notably than those in the eastern part as a whole in the study area. According to local meteorological data, the precipitation gently decreased and the temperature increased (about 1.7^°C) from 1975–2018. Overall, the decrease in the area of the wetlands and the temperature rises in the study area were mainly driven by the Mongolian monsoon climate, reduction in precipitation, and human activities.  相似文献   

玛曲湿地遥感影像提取及精度分析   总被引：1，自引：0，他引：1  

王迅  徐丹丹  李文龙 《国土资源遥感》2009,(4):96-100

以甘肃玛曲县为研究区,以区域湿地遥感信息提取为目标,采用TM多光谱数据和DEM数据,利用归一化植被指数和主成分分析得到的第一主成分作为分类特征,通过对数据的空间特征、波谱特征与统计结果的对比分析,构建湿地信息提取决策树模型,并与非监督分类法、最大似然法相比较,表明基于多特征决策树分类法能够用于湿地专题信息的提取,在研究区有较好的适用性。  相似文献   

开发区建设与沿海湿地的保护──烟台夹河口沿海湿地的开发与保护剖析     

徐家声  孟毅  孔繁荣 《海洋科学进展》1996,(1)

湿地为陆地上常年或季节性积水以及过湿的土地，还包括低潮时水深不超过６ｍ的水域，并与其衍生的生物种群构成特有的生态系统。我国是世界上湿地类型多，分布广的国家之一，按面积是世界上第三湿地大国．我国对湿地开发利用的历史悠久，早在周代就有利用湿地植物资源的记载，然而对湿地较系统的成因、保护及资源持续利用的研究则是在本世纪６０年代才开始．近几年由于对外开放发展经济的需要，在沿海兴建经济开发区，对湿地产生了伤害。本文以烟台夹河口沿海湿地的成因及其受损情况为例，探讨沿海开发区建设与湿地保护的问题，并提出一些保护措施。  相似文献   

大庆龙凤湿地须浮鸥巢址选择研究     

陈雪龙  杨焕民  齐艳萍  王晓龙 《湿地科学》2012,10(3):339-343

为了认知影响须浮鸥(Chlidonias hybridus)营巢的主要环境因素,于2011年6～7月,采用直接观察法和样方法在大庆龙凤湿地自然保护区内对须浮鸥的巢区进行了调查研究.在本次调查中共发现须浮鸥巢73个,逐巢进行了常规测量,并对须浮鸥巢址及附近无巢对照区域的生境进行了调查.主成分分析和独立样本t检验的结果表明,须浮鸥属于集群营巢,而影响须浮鸥巢址选择的主要因素依次为巢下水深、巢距植物距离、巢周明水面积、植物高度、植物密度和巢距干扰源距离.其中,前3个因素影响须浮鸥生境中食物的供给条件,后3个因素影响须浮鸥巢的隐蔽条件.须浮鸥选择巢址的条件是能提供丰富食物且具有较好隐蔽条件的生境.  相似文献