摘要
在 Gurbantunggut 沙漠的南部的部分的短暂植物系统地从 2002 ～ 2004 被监视，气象学的数据和土壤潮湿在一样的时期期间被分析。结果证明短暂植物萌芽和生长对水和热状况的变化敏感。超过 0 的每日的温度的时间 ?????????
Ephemeral plants in the southern part of Gurbantunggut Desert were systematically monitored from 2002 to 2004 and the meteorological data and soil moisture during the same period were analyzed. The results show that the ephemeral plants germination and growth are sensitive to the changes of water and heat condition. The time for daily temperature over 0℃ in early spring in 2003 was delayed nearly 10 d compared with that in 2002, while the soil water changed little in the same period. Observation showed that there were 28 ephemeral species germinated in 2002, their life period was about 70 d in spring, and the maximum cover of ephemeral synusia reached 46.4%. However, only 17 ephemeral species germinated in 2003, their life period was about 50 d in spring, and their maximum cover was only 20.8%. The height of ephemeral plants was significantly higher in 2002 than that in 2003. It can be seen that ephemeral plant germination and growth in spring are strongly dependent on temperature. The changes of water conditions can affect ephemerals germination and growth as well. Because no heavy precipitation occurred during summer in 2002, only a few ephemerophytes were observed in autumn after ephemerals completed their life circle in early spring. However, about 60 mm precipitation was recorded from July to August both in 2003 and in 2004. Some ephemerals such as Erodium oxyrrhynchum and Carex physodes, etc. covered the dune surface rapidly with a cover 〉10%. Therefore, the ephemerals not only germinate in autumn after the early spring, some species may germinate in summer if adequate rainfall occurs. The study on responses of ephemerals growth to water and heat conditions not only has a certain ecological significance but also contributes a better understanding to the effect of climate changes on the desert surface stability.
基金
supported by the Key Knowledge Innovation Project of the Chinese Academy of Sciences(Grant Nos.KZCX3-SW-343-3&KZCX3-SW-326-4)
the Natural Science Foundation of Xinjiang Uygur Autonomous Region(Grant No.200421128)
the Project of 0asis Person with Ability in Xinjiang.
关键词
短生植物
水热环境
Gurbantunggut沙漠
积极响应
germination and growth of ephemerals, water and heat variation, active response, Gurbantunggut Desert.
