海南东寨港海莲群落林隙结构及其更新特征

Canopy Gap Structure and Regeneration Character of Bruguiera sexangula in Dongzhai Harbour,Hainan Island

海南东寨港河港海莲群落最主要的干扰类型是树木的大量枯死,约占57%;以20～40m2面积大小的林隙最多,平均每个20m×20m样方中有2.5个,占样方内林隙总数的37.1%;河港海莲群落中林隙绝大多数是由1～4株枯立木所形成;最大围径集中分布在50～60cm、60～70cm2个径级内,约占调查样方林隙枯立木总数的45%;林下幼苗密度高于林隙幼苗密度,而林隙的幼苗高度比林下幼苗高度高,适当的林隙能促进更新;海莲对林隙面积大小的更新反应强于尖瓣海莲。

The mass mortality of standing trees is the major disturbance type of Bruguiera sexangula community in Hegang Village, Dongzhai Harbour, Hainan Island, which contributed to about 57 % of the total disturbance types. The canopy gaps of between 20-40 m^2 were found the highest in the community with 2.5 gaps per sample plot of 20 m×20 m, occupying 37.1% of the total gaps. Most of the canopy gaps of the B.sexangula community were formed by 1-4 standing dead trees. The largest dead trees mainly fell into 2 groups, 50-60 cm and 60-70 cm in diameter, and made up for 45 % of the total dead trees in the sample plot. The saplings under the forest trees grew at a higher density than those under the canopy gaps but were shorter in height. Appropriate canopy gap promoted regeneration. The regeneration of Bruguiera sexangula produced higher response to the canopy gap size than that of the B.sexangula var.rhynchopetala.