放牧、刈割及摘顶对亚热带人工草地牧草种群的影响

通过比较放牧、刈割及摘顶3种干扰发现，适度放牧、刈割提高了亚热带高山人工草地鸭茅、黑麦草种群的适应性，部分原因在于2种干扰均对牧草进行了摘顶．摘顶解除了牧草的顶端优势及生殖生长。放牧、刈割对牧草产生的生态影响在某种程度上可通过摘顶而实现。从而提高种群密度、热值及能量积累．单因子的人工摘顶试验表明，牧草顶端优势的维持降低了牧草种群密度，抑制了能量积累。从抑制了种间竞争．持续摘顶解除了牧草的顶端优势。促进了牧草密度及能量的增长，从而提高了牧草种群的竞争力．

Effects of grazing, cutting and decapitating on grass populations on the artificial grassland in subtropical zone of China

Studies on the effects of grazing, cutting and decapitating on grass populations on the artificial grassland in the subtropical zone of China showed that moderate grazing and cutting could increase the adaptability of Dactylis glomerata and Lolium prenn due to decapitating. Decapitating could rescind the apical dominance and reproduction growth of grass, and hence,the ecological effects of grazing and cutting on grass could be realized by decapitating, and the population density, caloric value and energy accumulation of Dactylis glomerata and Lolium prenn increased obviously. Apical dominance of grasses could lower the population density, energy accumulation and intra population competitive ability.