深圳盐灶银叶树种群的生物学特性研究

Biological characteristics of Heritiera littoralis population in Yanzao, Shenzhen

对深圳盐灶银叶树种群的生物学特性进行研究,发现该种群的实际分布面积仅0.7 hm2,个体数不足1 500,且还在减少;年龄结构虽然呈近似金字塔形,但幼龄及中等个体数少,呈一定的瓶颈现象,其陆生亚种群年龄结构呈倒金字塔形.自然情况下,产种子少,种子萌发率低,幼苗向成苗转化率低;去外壳能缩短银叶树种子的萌发时间,但一定程度上增大银叶树幼苗的死亡率.研究结果表明,深圳盐灶银叶树种群已处于严重受威胁状况,亟需保护.

Study on biological characteristics of Heritiera lhtoralis populations showed that this population had a narrow colonization area of only 0. 7 hm^2. There were less than 1 500 individuals, and the number of individuals were decreasing continually. Though the population age structure was approximately pyramid-like, there were few young and middle-aged individuals, and the age structure of terrestrial subpopulation was reversed pyramid-like. The seed production of H. littoralis was low in nature, and so was the germination rate as well as the transformation rate from juvenile to adult. In addition, our laboratory experiments showed that removing shell of seeds was helpful to shorten the germination time but decreased the seedling survival rate of H. littoralis. The results show that the survival of H. littoralis population in Yanzao have been threatened seriously, and urgently needed to take effective actions to preserve the plants and habitats on site.