额济纳盆地1977～2005年景观格局演化及其生态学机制

基于1977、1993、2001和2005年四期Landsat遥感影像资料,综合运用遥感与GIS技术,分析了近30年来额济纳盆地景观格局的演化特征及其生态学机制。结果表明:(1)乔木林的结构不合理和回复力较低导致其始终处于退化之中,对黑河输水量变化的响应具有滞后和延迟效应;(2)灌木物种生态型的多样性较高,使得灌木林对水分变动的响应表现出一定的弹性,在快速退化后保持相对稳定;(3)草本植物对水分变动的响应十分敏感,草地的面积和空间分布受黑河输水量影响最为显著;(4)沙地总面积持续增加,单个沙丘的规模增大,与沙尘暴发生频率减少但强度持续增大的趋势相一致;(5)水域和干湖盆的景观格局具有明显的波动特点,主要受黑河向盆地内的输水量与输水方式控制。

Landscape Pattern Evolution and Its Ecological Mechanism in Ejina Basin from 1977 to 2005

Using remote sensing techniques and GIS,the characteristics and ecological mechanism of landscape patterns evolution in Ejina basin were studied based on Landsat data in 1977,1993,2001 and 2005.It is found that:(1) Arbor woods degenerated continuously in the study period and presented lag and delay to the change of Heihe River flow because of the structure defects and low elasticity to disturbance;(2) Shrub woods showed resistant to water change due to high shrub species diversity,and kept relatively stable after degeneration in the period of 1977-1993;(3) The total area and spatial distribution of grassland changed in step with Heihe River flow because herb responded sensitively to water variability;(4) The total area of sand land and size of individual dune increased continuously,which was in consistent with the trend of decreasing frequency but increasing intensity for sandstorms in the study area;(5) Water and dry lake fluctuated obviously due to the change of Heihe River flow and water discharge project.