关键词: 砂生槐, 沙埋, 种子萌发, 幼苗生长

Abstract: Sand burial is an important influence factor on seed germination and seedling survival in the desert land. Sophora moocroftiana is an endemic psammophyte in Tibet, which mainly distributes in the wide valley of the middle reaches of Yalu Tsangbo River as well as its several main tributaries such as Nianchu River and Lasha River. This paper studied the effects of different temperature and different sand burial depth on seed germination and seedling emergence of S. moorcroftiana under experimental treatments. Results show that temperature and sand burial depth have significant effects on seed germination and seedlings emergence rate of S. moorcroftiana. In the temperature range of 15~30 ℃, S. moorcroftiana seed germination rates decreases significantly with temperature increasing, and the seed germination rate reaches the maximum value at 15 ℃. S. moorcroftiana seeds can germinate when the depth of sand burial is no bigger than 10 cm, and S. moorcroftiana seedlings can emerge when the depth of sand burial is no bigger than 8 cm. In the ranges, the seed germination rate and seedling emergence rate decrease with the sand burial depth increasing. Seedlings of S. moorcroftiana can survive when the sand burial depth is up to 33% of plant height, and their total biomass are bigger than the unburied seedlings. When the sand burial depth is at 66% of seedling height, the survival rate of the seedlings decrease to 43％ and the growth is inhibited. Seedlings of S. moorcroftiana can not survive when the sand burial depth is up to 100％ and 133％ of seedling height. So it is obvious that the ecological adaptive strategy of S. moorcroftiana in desert land is to redistribute.

Key words: Sophora moorcroftiana, sand burial, seed germination, seedling growth