湿地景观破碎化对东方白鹳栖息地的影响——以三江平原东北部区域为例

以野外栖息地要素调查为基础,通过模型定量化分析,研究了三江平原东北部湿地景观破碎化过程及其对东方白鹳栖息地的影响。结果显示:当景观面积占区域面积超过50%,景观连通度高于50时,景观基质处于低度破碎化状态,景观斑块面积丧失对栖息地影响显著;当景观面积占区域面积小于30%,景观连通度低于30时,景观处于高度破碎化状态,景观空间隔离、斑块形状以及景观结构对栖息地影响更为显著。景观破碎化过程中,沼泽湿地主要在面积丧失方面对东方白鹳觅食地产生影响;而湖泡和岛状林湿地在斑块数量丧失和空间隔离方面对东方白鹳筑巢地和觅食地产生显著影响。

Effects of Wetland Landscape Fragmentation on Habitats of Oriental White Storks-A Case Study on Northeastern Sanjiang Plain, China

The northeastern Sanjiang Plain was once a largest fresh water wetland distribution area in China and an important habitat for Oriental White Storks (Ciconia boyciana)as well.But,with several large-scale land reclamation activities taking place in this region,large area of wetlands was converted into farmlands.As a result,wetlands were in very serious fragmented state,and very few Oriental White Storks were found in the heart of the study area since the 1980s.This phenomenon seems to be clearly related to wetlands changes in landscape scale. So, based on detailed field surveys on wetland landscape and habitat factors for Oriental White Storks,we established a GIS model to analyse the effect of wetland changes on habitats of Oriental White Storks in the study area.We got conclusions as follows:(1) The habitats of Oriental White Storks were composed of complex landscape of wetland types, in which island-like forest swamps were as nesting area and marshes,lakes and ponds as feeding area for Oriental White Storks in the study area.(2) Wetland landscape fragmentation has very serious impacts on habitats of Oriental White Storks. Patch area of wetlands had more effects on habitats when landscape matrix was in a lower fragmented state,that is,wetland area accounted of more than 50% of the total study area and landscape connectivity was higher than 50;and isolation in landscape,patch shape as well as landscape structure had more effects on habitats when wetland landscape was in higher fragmented state, that is,wetland landscape area accounted for less than 30% of the total study area and landscape connectivity was lower than 30.(3)Marsh wetland had more negative effects in area loss on habitats and lakes and ponds as well as island-like forest swamp had more negative effects in loss of patch number on habitats in the process of landscape fragmentation.(4)The restoration of habitats for Oriental White Storks needs to restore the key landscape types such as island-like forest swamp,ponds and marshes,to increase the connectivity between landscape of wetlands,to enlarge landscape matrix area and to restore landscape structure in landscape scale in the Sanjiang Plain for the feature.