内蒙古荒漠草原短花针茅叶片功能性状对不同草地经营方式的响应

Response of Grassland Using Modes to Leaf Trait of Stipa breviflora in Desert Steppe of Inner Mongolia

植物叶片功能性状对不同草地经营方式的适应是一种有效地生态对策。短花针茅(Stipa breviflora)是亚洲中部暖温性荒漠草原的主要建群种,通过调查生长良好的不同龄级短花针茅叶性状,试图揭示荒漠草地利用模式与植物生态响应机制。该研究测量自然叶高(LNH,leaf natural height)、叶长(LL,leaf length)、叶鲜质量(LFW,leaf fresh weight)、叶干质量(LDW,leaf dry weight)、自然叶宽(LW,leaf width)、叶缘距(LED,leaf edge distance)、叶直立度(leaf erection index,LEI)、叶卷曲度(leaf rolling index,LRI)和叶干物质含量(leaf dry matter content,LDMC)等叶性状指标。结果表明,(1)短花针茅的LNH、LL、LFW、LDW、LW、LED等叶性状在灌溉草地几乎都显著大于放牧草地和围封草地。(2)LEI、LFW为生境干扰响应的敏感性状;LW、LDMC为生境干扰响应的惰性性状。(3)Pearson相关分析结果可知,放牧对短花针茅叶性状影响最大。研究认为,短花针茅叶片功能性状对不同草地经营方式的的适应对策,是通过对不同性状的权衡,充分利用环境资源来完成的。

The trade-off of plant function traits to adapt the different habitats is a kind of effective ecological strategy. Stipa breviflora is the main edificator in warm-temperate desert grassland. The responseof S. breviflora leaf traits to grassland using modes may reveal the modern desert grassland resource utilization and plant ecological response mechanism. Therefore, we investigatedS. breviflora by measuring its leaf traits in different age classes in the manual irrigation grassland, grazied grassland and ungrazed grassland. The results showedS. breviflora’s leaf natural height, leaf length, leaf fresh weight, leaf dry weight, leaf width and leaf edge distance in the manual irrigation grassland were larger than the leaf traits in the grazed grassland and in the ungrazed grassland. Leaf erection index and leaf fresh weight were sensitive characters to habitat disturbance. Leaf width and leaf dry matter content were inert characters. The degree of response to grassland using modes and its variation fit the linear regression relationship (y=ax+b) onS. breviflora leaf traits. By pearson correlation analysis, there was a greater influence on the leaf traits to grazing. Our study suggested grassland using modes led to the leaf traits differentiation of the desert grassland edificator in Mongolian Plateau,S. breviflora plasticity trade-off through a variety of leaf traits in response to the habitats to complete its life cycle under the metastable ecological system.