干旱区生态环境知识资源中心

Two years study was conducted to examine the influence of microhabitats i.e., plant canopies and interspaces oil the seedling emergence and Survival of Seriphidium quettense in relation to soil temperature and soil moisture in natural habitat. The growth rate of first year seedlings are also examined. Relative abundance of microhabitats was determined by using square quadrates. Soil temperature and soil moisture of two microhabitats were recorded at 0-5, 5-10 and 10-15 cm depth. Results showed that soil moisture ill Spring was found critical for seed germination while ill summer it had greater impact oil the survival of first year seedlings. Precipitations in March and April promoted seed germination while monsoon rains influenced seedling survival. Soil Moisture and soil temperature in different microhabitats were significantly different in different months, reflected significant influence upon seedling emergence and their Survival. Seedling emergence and survival was higher under plant canopies than in open interspaces. Highest mortality rate of first year seedlings were observed ill June and August under high soil temperature and low soil moisture contents. High soil moisture in July due to occurrence of precipitation decreased the mortality rate of first year seedlings. After winter, no mortality occurred. Survived seedlings of the first year had high root to shoot ratio. Results further depicted that conspecific plant canopies are favorable microsites for,seedling Survival. Furthermore, high root to shoot ratio may enable them to survive in arid habitat.