三江平原淡水湿地生态系统景观格局特征研究——以洪河湿地自然保护区为例

对我国所剩为数不多的淡水湿地植物生态系统原生景观结构特征进行定量分析对于湿地保护与恢复具有重要意义。论文以多年期遥感影像提取洪河国家级湿地自然保护区植物分类信息,在GIS支持下,进行了群落、植被型和景观带3个尺度的景观格局分析。结果表明,草甸灌丛景观是研究区的基质性景观,草甸和沼泽湿地共同占据了研究区植被型的核心地位,小叶章-苔草群落则是植物优势群落。植物生态系统空间格局特征表现为:草甸灌丛分布在广阔的河间干湿交替地带,沼泽湿地主要成条带延伸于河道与洼地带,岛状林则出现在地势较高的岗地段,呈断块分布。研究区典型沼泽湿地面积7年间缩小约10%,周边人类活动造成水资源缺失是退化主要驱动因素,应尽早实行以流域为管理单元的自然资源管理体制。

Probe into the Landscape Pattern of Freshwater Wetland Communities--A Case Study in the Honghe National Nature Reserve in Sanjiang Plain,China

It is very significant to study both landscape pattern and its structure of plant communities in vast wild freshwater wetlands in China which are few in number.Such a research promotes both protection and restoration of wetlands which are threatened by intensive human activities.By interpreting Multi-temporal TM images,we generate wetland classification information in the HNNR(Honghe National Nature Reserve)in Sanjiang Plain,Northeast China.Furthermore,both landscape pattern and its structure are analyzed at three levels of plant community,vegetation type and landscape with support of GIS technology.Our investigation demonstrates that meadow and shrub have been the basic landscape in the study area,while mire and meadow alike take the core position at vegetation type level as well as Ass.Calamagrostis angustifolia-sundry herbs as dominant plant communities.Our research indicates the spatial pattern of wetland landscape in HNNR as follows:meadow and shrubs are distributed in the wide place of the low gradient riverbank,mire exists in the riverway or low-lying depressions as narrow riparian landscape corridor,while island forests are distributed in the higher areas separately.Our research result also shows that 10% of typical mires area have lost during the last 7 years in the study area,indicating an obvious trend of degradation of mire wetlands,which attributed mainly to the irrigation activities of human beings on farms around HNNR.So the present management unit needs to be reformed into watershed objective constitution for efficient protection of natural resources as an urgent measurement in case of further degeneration.