火干扰对内陆荒漠湿地芦苇群落特征的影响

采用人为起火的方法，通过对比敦煌西湖荒漠湿地干扰区域和未干扰区域火后第一年芦苇群落特征的变化，探讨内陆荒漠湿地植被对火干扰的响应机制。了解火干扰对内陆荒漠湿地芦苇群落特征的影响。结果表明: 火干扰能够延长植物青绿期，促进了植被的个体发育；火干扰对草本层植被盖度、高度均有显著的负面影响，而对密度有显著的正面影响，对灌木层植被群落盖度、高度及密度均有正面影响，但影响不明显；火干扰后植物群落Shannon-Wiener多样性指数H′、Simpson多样性指数D和Simpson优势度指数C均减少，而Margalef物种丰富度指数Ma和Pielou均匀度指数J均增加；火干扰致使草本层植物群落多样性指数与研究区植物群落总体多样性指数变化趋势一致，致使灌木层物种H′、D和J指数均减少，而Ma和C指数均增加；火干扰致使植物群落地上总的生物量降低，主要使灌木层生物量降低，而使草本层生物量有所增加。

Effect of fire disturbance on reed（Phragmites australis Trin）community characteristics in inland desert wetland

This study discussed the response mechanism of vegetation to fire disturbance in inland desert wetlands by comparing the effect of fire disturbance on the characteristics of reed communities in the Xihu wetland, Dunhuang City,Gansu Province,China.Results revealed that fire disturbance could prolong the green period of plants and promote the individual development of vegetation.Fire disturbance had a significant negative effect on vegetation coverage and height and a significant positive effect on the density of the herbaceous layer.Furthermore,fire disturbance positively affected the coverage,height,and density of the shrub community;however,this effect is not obvious.After the fire disturbance,the Shannon Wiener H′,Simpson D,and Simpson C indices of plant communities decreased,whereas the Margalef Ma and Pielou J indices increased.Moreover,the same change trends in plant community diversity indices such as H′,D,and J diversities appeared in the herbaceous layer of the reed community in the study area,whereas an opposite trend in Ma and C indices was observed.In summary,fire disturbance can reduce the total aboveground biomass of plant communities,particularly the biomass of the shrub layer,and it can increase the biomass of the herbaceous layer.