关键词: 滨海湿地, 内生真菌, 芦苇, 盐度胁迫

Abstract: The effect of disturbances on the changes of forest landscape is a long-term process. Traditional observation methods are hard to explore the long-term effect of disturbances on forest landscape at large spatial scale, while model simulation is a commonly used method at present. In this paper, a spatially explicit landscape model, LANDIS, was used to simulate the longterm (300 years) dynamics of forest landscape under four different forest harvest scenarios, i.e., no cutting, clear cutting, gradual cutting, and selective cutting, in the Huzhong forest region of the Daxing’an Mountains. We analyzed the mean patch area, aggregation index, percent cover, and age structure of the two typical forest types, larch and white birch. The results showed that forest harvest reduced the percent cover of larch forest while increased that of white birch forest, and there were no significant differences among the various forest harvest scenarios. As compared with other forest harvest scenarios, clear cutting decreased the aggregation level of larch forest while increased that of white birch forest significantly. During the early-stage of the simulation, forest harvest reduced the mean patch area of larch forest while increased that of white birch forest. Clear cutting increased the percent cover of the saplings and middle-aged cohorts of larch and white birch forests significantly, as compared to other forest harvest scenarios. It was concluded that forest harvest, especially clear cutting, promoted the fragmentation of forest landscape, and thus, under the same forest harvest intensities, selective cutting should be adopted as far as possible to reduce the effect of forest harvest on forest ecosystems, and further, to promote the healthy and sustainable development of forest ecosystems.

Key words: coastal wetland, endophytic fungi, salt stress., Phragmites australis