摘要
基于长序列遥感影像数据、水位日观测数据以及高精度湖盆地形数据,通过提取洞庭湖19872016年湿地植被信息,并构建表征水位波动的多周期水情变量,采用逐步回归分析法识别影响洞庭湖湿地植被分布格局的关键水情变量并建立其与植被面积的响应关系.结果表明:1)19872016年,洞庭湖湿地典型植被面积在全湖尺度上呈增加趋势,尤其是林地面积,占比由1.77%上升为7.24%.湿地植被格局演变上,东洞庭湖呈现芦苇群落挤占苔草群落空间,并推动湿地植被整体向湖心扩张的趋势.2)影响东洞庭湖苔草和芦苇分布最关键的水情变量是丰水期水位.苔草对丰水期水情存在非线性阈值响应,丰水期平均水位维持在29 m左右,最适宜苔草生长;对于芦苇,丰水期偏枯的水情条件对其生长发育起到促进作用.涨水期和退水期水文过程是影响东洞庭湖湿地植被分布的次为重要的水情因子.涨水期、退水期水位偏低的水情条件对芦苇分布面积的扩张起促进作用.
In this paper,based on the remote sensing image data,the hydrological data from 1987 to 2016,and the high-resolution topographic data,we extracted the wetland vegetation information of the Lake Dongting and constructed the multi-cycle water level fluctuation measurement.On this basis,stepwise regression method and polynomial fitting were used to estimate the key hydrological variables and to quantify the effects of hydrological process on the two typical wetland vegetation.The main conclusions as follows:1)From 1987 to 2016,the area of the whole vegetation had a significant increasing trend in the whole wetland,especially the Populus euramevicana community.And in East Lake Dongting,the Phragmites australis community occupied the space of Carex brevicuspis community,which promoted the whole beach to the center of the lake.2)Water level fluctuation in flood season was the determinant towards the distribution of Carex brevicuspis and Phragmites australis.There was a non-linear response of water regime to the area of Carex brevicuspis.When the average water level was about 29 m during flood season,it will be most suitable for the growth of Carex brevicuspis.For the Phragmites australis community,low flow in flood season was more favorable for its growth and development.Water level fluctuation during rising and retreating season were the secondary important regime factor influencing the distribution of wetland vegetation in East Lake Dongting.Lower water level in the two season can facilitate the distribution of Phragmites australis.
作者
周静
万荣荣
吴兴华
张宇
ZHOU Jing;WAN Rongrong;WU Xinghua;ZHANG Yu(Key Laboratory of Watershed Geographic Sciences,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,P.R.China;Chinese Academy of Natural Resources Economics,Beijing 101149,P.R.China;University of Chinese Academy of Sciences,Beijing 100049,P.R.China;China Three Gorges Corporation,Beijing 100038,P.R.China)
出处
《湖泊科学》
EI
CAS
CSCD
北大核心
2020年第6期1723-1735,共13页
Journal of Lake Sciences
基金
中国科学院重点部署项目(KFZD-SW-318)
中国长江三峡集团有限公司项目(201903144)联合资助.
关键词
湖泊洲滩湿地
典型植被景观带
时空格局
水文响应
洞庭湖
Lake wetland
typical vegetation zones
spatio-temporal pattern
hydrological response
Lake Dongting