羊草草原火烧效应的模拟实验研究

用控制火烧和模拟实验的方法研究了内蒙古羊草草原的火烧效应及其作用机理。实验结果表明,火烧对个别植物更新芽的伤害、火烧后土壤有效氮的变化和枯落物的移走是造成植物种群及群落发生变化的重要原因,尤其是建群种羊草的显著增加更与火烧后优势种大针茅的受害和土壤有效氮的增加密切相关;而土壤有效氮的增加和羊草优势度的提高,则可能是群落内物种多样性发生变化的重要原因。

The Simulated Experimental Research on the Fire Effects on Leymus chinensis Steppe

With the methodof controlled burning and simulated experiment, the fire effects and its action mechanismon Leymus chinensis Steppe in Inner Mongolia were researched. The results showed that theimportant reasons causing plant populations and community changes were the injury of fireto some plants' regeneration buds, the change of soil nitrogen content after burning andthe remove of litters. Especially, the obvious increase of Leymus chinensis (communityconstructive species) related closely with the injury of fire to Stipa grandis (dominantspecies) and the increase of available nitrogen. The increase of available nitrogen andthe raise of Leymus chinensis dominant degree may be the important reasons for the changeof the species diversity in the community.