摘要
在沙地环境中,沙埋是影响植物种子萌发和幼苗存活的一个重要因素。砂生槐是西藏特有的沙生植物,主要分布在雅鲁藏布江中游地区及拉萨河、年楚河等主要支流宽谷区。对砂生槐幼苗进行了控制沙埋试验,研究了不同温度和沙埋深度对砂生槐种子萌发特性的影响。结果表明,温度和沙埋深度显著影响砂生槐种子的萌发率和出苗率。在15～30℃的温度范围内,随着温度的升高,种子萌发率显著下降,15℃时,其种子萌发率达到最高值;砂生槐种子能在深度≤10cm的沙埋中萌发,≤8cm的沙埋中出苗,在此范围内,随着沙埋深度的增加,砂生槐种子的萌发率和出苗率逐渐降低。沙埋深度在植株高度的33%时,砂生槐幼苗能够存活,且总生物量大于未沙埋幼苗;当沙埋深度增至植株高度的66%时,砂生槐幼苗存活率降至43%,生长受到抑制;而当沙埋深度增至植株高度的100%和133%时,没有砂生槐幼苗存活。可见砂生槐植株在适应沙埋环境方面主要采用调整生物量分配模式的生态对策。
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.
出处
《中国沙漠》
CSCD
北大核心
2011年第6期1437-1442,共6页
Journal of Desert Research
基金
"211"工程师资队伍建设项目(SZRC-211-09)资助
关键词
砂生槐
沙埋
种子萌发
幼苗生长
Sophora moorcroftiana
sand burial
seed germination
seedling growth
