海南岛木麻黄海防林天然更新特征及更新树种筛选

天然更新是森林资源再生产的一个重要的生态学过程,良好的天然更新可促进人工林向近自然林的方向转变。为了解海南木麻黄海防林天然更新现状和特征,筛选出自然条件下天然更新良好的树种。该研究在海南岛木麻黄海防林内共计设立临时样地73块,样地总面积为2.51 hm~2,采用典型抽样的调查方法对海南全岛木麻黄海防林天然更新状况进行系统调查,应用天然更新密度及物种丰富度等指标对干、湿不同气候区木麻黄天然更新特征进行比较分析,并应用更新密度、更新指数等指标对天然更新质量较好的树种进行筛选。结果表明:(1)海南岛木麻黄海防林下天然更新质量整体不佳,木麻黄自身虽无法实现天然更新,但局部其他树种天然更新良好,更新良好的比例为15.1%。(2)湿润区天然更新丰富度及物种多样性远优于半干旱区,其中湿润区样地更新树种为28科、50属、59种,半干旱区样地更新的树种为6科、6属、6种。(3)乔木更新情况优于灌木。(4)潺槁木姜子、鸦胆子、台湾相思、榄仁树等具有较强的天然更新性能,适合与木麻黄混交,可以作为木麻黄海防林的混交树种或伴生树种。

Natural regeneration characteristics and selection of regeneration tree species of Casuarina equisetifolia coastal windbreaks in Hainan Island

Natural regeneration is an important ecological process of forest resource reproduction, and good natural regeneration can promote the transformation of artificial forest to near natural forest. In order to understand the status and characteristics of natural regeneration of Hainan Casuarina equisetifolia coastal windbreaks, and to select the species with good natural regeneration under natural conditions, the natural regeneration status of Hainan C. equisetifolia coastal windbreaks was systematically investigated in this study by typical sampling method, and the natural regeneration characteristics of C. equisetifolia in different dry and wet climate zones were compared and analyzed by using the indexes of natural regeneration density and species richness; the tree species with better natural regeneration quality were screened by regeneration density and regeneration index. A total of 73 temporary quadrats were set, with the total sample areas of 2.51 hm². The results were as follows:(1)The overall quality of natural regeneration in C. equisetifolia costal windbreaks was not good, and C. equisetifolia could not achieve the natural regeneration by itself, but the natural regeneration of some other species was good in local area, and the percentage of good regeneration was 15.1%.(2)The natural regeneration richness and diversity in the wet zone were much better than that in the semiarid zone, in which there were 28 families, 50 genera and 59 regeneration tree species in the wet zone; there were only 6 families, 6 genera and 6 regeneration tree species in semiarid zone.(3)The regeneration of trees was better than that of shrubs.(4) Litsea glutinosa, Brucea javanica, Acacia confusa, Terminalia catappa, et al. were found to have stronger natural regeneration capability, therefore, they were suitable for mixing plantation with Casuarina equisetifolia and could be used as mixed tree species or associated tree species of C. equisetifolia costal windbreaks.