内蒙古典型草原克氏针茅与冰草的生存策略

在内蒙古自治区多伦县中科院植物所生态恢复试验站，选择优势种克氏针茅(Stipa krylovii) 和冰草（Agropyron cristatum），使用Li-6400便携式光合测定系统观测光合生理生态特征的生长季变化(DOY155-265)。结果表明：水分是本区域植物生长的最重要的限制因子。冰草与针茅受5cm和20cm表层土壤含水率的影响较大。水分是本区域植物生长的最重要的限制因子。冰草与针茅受5cm和20cm表层土壤含水率的影响较大。植物的光合速率和蒸腾速率受自身的气孔导度限制，光合速率和蒸腾速率随气孔导度的增大而增大，冰草这一特征较为明显，即冰草对环境响应更为敏感。作为优势种冰草和针茅的生态适应策略并不相同，针对当地现有环境条件，针茅更具生存优势。随着全球环境变化，干旱胁迫对草原生态系统产生了重大影响，使得这些地区成为响应环境变化的敏感区域，通过对半干旱温带草原优势种克氏针茅和冰草对光、水等环境资源的利用及之间的关系研究，有助于我们对全球环境变化提出本区域合适的应对策略。

Survival strategy of Stipa krylovii and Agropyron cristatum in typical steppe of Inner Mongolia

The ?eld experiment was conducted at typical semi-arid grassland in Duolun County, Inner Mongolia, China. We chose the dominant species Stipa krylovii and Agropyron cristatum, observed Physiological and ecological characteristics of photosynthetic in the growth season (DOY155-265) by Li-6400. The result shows: The soil moisture is one of the key limiting factors for the survival and growth of plant species in arid and semi-arid steppe regions. Agropyron cristatum and Stipa krylovii is affected greatly by soil moisture content in 5cm and 20c soil layer. Plant photosynthetic rate and transpiration rate are limited by one's own size of stoma, which increased with stoma, Agropyron cristatum is more obvious. In other words, Agropyron cristatum will respond more sensitive to the environment. It is different that the ecological adaptation tactics of Stipa krylovii and Agropyron cristatum, and Stipa krylovii have advantage of surviving even more. As the global environmental changes, drought stress has had a significant impact on grassland ecosystems. We studied Stipa krylovii and Agropyron cristatum how to utilizing environmental resources such as light, water, etc., and the relations between environmental resources and plants. Our aim is to provide suitable plan for this area.