Carex dynamics as an environmental indicator in the poyang lake wetland area: Remote sensing mapping and GIS analysis

Abstract

It is of considerable importance to analyze the changes in Carex distribution and environmental elements in order to protect and exploit the wetland resources of the Poyang Lake wetland area, one of the most important wetlands in the world. Employing multitemporal remote sensing images acquired on October 31st, 2005 and December 10th, 1999, the authors determined the dynamic distribution of Carex by combining spectral angle mapping technologies. Then, for the first time, Arc View GIS-based statistical analysis was performed on the Carex dynamics. Finally, the relationship between the Carex dynamics and delta change, and the landscape fragmentation index of Carex were further analyzed. It was found that: (1) the extent of Carex in the Gan River delta, particularly in the north distributary of the river, was directly correlated to lake sedimentation and regional drought in the same year; (2) the distribution of migratory birds is influenced by factors additional to the distribution of Carex; and (3) the wetland landscape ecology of the Poyang Lake wetland area is facing threats from human disturbance and needs further attention if it is to retain its status as an important bird habitat. © 2007 Taylor & Francis Group, LLC.