海南岛热带海岸多种乡土树种海防林的构建及群落动态研究

A Study on Construction and Dynamics of a Tropical Coast Plant Community with Multiple Native Tree Species as Windbreak on Hainan Island

在木麻黄海防林下分别采用单种乡土树种和多种乡土树种与木麻黄混交2类方式进行种植,对乡土树种的存活率、生长情况以及环境因子等进行了持续性的观测,并对2类种植方式样地中的乡土树种的生长情况进行比较分析。结果表明:在木麻黄海岸防护林中混交种植的乡土树种大都能够成林。经过5 a的生长,7种乡土种树木中草海桐和露兜的存活率最高(48.89%),水黄皮次之(42.22%),海棠果的最低(13.33%)。多种混交样地植物平均株高、基径分别从75.2、1.3 cm增长至185.4、5.1 cm。4种乔木树种中水黄皮的生长量增量最大,其次为海棠果和黄槿,小叶榕的生长量增量相对较小;3种灌木中草海桐的生长量增量较大,苦郎树、露兜次之。水黄皮和小叶榕的平均相对生长量增量和光合作用强度均表现为多种混交样地大于单种混交样地,且2种类型样地中水黄皮的各类生长指标均大于小叶榕。多种混交样地和单种混交样地的土壤含水量与土壤pH值均有显著提高。乡土树种在混交林中生长良好,且显著地改善了混交林的土壤环境,可用乡土树种构建混交林型的海防林。

In the Casuarina equisetifolia plantation as coast windbreak,the native tree species were planted in 2 patterns,i.e.plots with single native tree species and plot with multiple native tree species,the survival rate and growth of native tree species and the environmental factors were observed continuously and the comparative analysis of the growth of native plants in the 2 planting patterns was conducted.The results showed that most of the native tree species planted in the Casuarina equisetifolia coast windbreak could survive to form mixed forest.After 5 years'growth,the survival rates of Scaevola sericea and Pandanus tectorius were the highest(48.89%)among the 7 native tree species,and then Pongamia pinnata(42.22%),while Calophyllum inophyllum was the lowest(13.33%).The average plant height and base diameter of plants in mixed plots with multi-species increased from 75.2 cm and 1.3 cm to 185.4 cm and 5.1 cm respectively.Among the 4 arbor species,the growth increament of Pongamia pinnata was the largest,and then Calophyllum inophyllum and Hibiscus tiliaceus,while the growth increment of Ficus microcarpa was relatively small.Among the 3 shrub species,the growth increment of S.sericea was largest and then Clerodendrum inerme and the last Pandanus tectorius.The average relative growth increment and photosynthetic intensity of Pongamia pinnata and F.microcarpa were larger in mixed plot with multi-species than in mixed plots with single species.In both types of plots,all the growth parameters of Pongamia pinnata were larger than those of F.microcarpa.In this study,the soil water contents and soil pH values increased significantly.The native tree species grow well in the mixed forest and have improved the soil environment apparently.The native tree species could be employed to construct mixed forest with multi-species as coast windbreak.