浙江省生态公益林植被恢复过程中物种组成及多样性的变化

Changes of species composition and diversity in the restoration processes of ecological public-welfare forests in Zhejiang, East China

在浙江省生态公益林区域的现状植被中分析了6种主要群落类型的物种组成和多样性的变化格局,包括演替系列中的2种灌丛、松优势林、2种混交林和常绿阔叶林。结果表明含松较多的灌丛和松优势林常分布在环境退化较严重(土层瘠薄)的生境中,其中灌木层主要由阳性的映山红、木、白栎等组成,常绿阔叶林优势种木荷、青冈、苦槠、甜槠等在其中偶见,因此推断其自然恢复为常绿林的速度慢;含常绿阔叶树较多的灌丛及含松较少的混交林分布在土层较厚处,木荷、青冈、苦槠、甜槠等的频度和重要值都较大,较容易自然恢复为常绿阔叶林。各种群落中物种多样性指数——Gleason、Shannon-Wiener、Simpson指数基本上以常绿阔叶林为最高,其次是含松较少的混交林,含松较多的灌丛和松优势林各种多样性指数最低。本研究显示我国中亚热带东部森林植被恢复途径有3条:(1)灌草丛→针叶林(松)→针(松)阔混交林→常绿阔叶林;(2)灌草丛→针(松)阔混交林→常绿阔叶林;(3)灌草丛→常绿阔叶林。这意味着本区域的常绿阔叶林恢复可以不必经历松林阶段,在生境条件较好的地方通过人工干预、补种常绿阔叶树可以加速常绿阔叶林恢复。

Public-welfare forests contribute many ecological benefits for the human community compared with the commercial woodlands. The vegetation of Zhejiang had been havoc in the 1950＇s. The composition and plant diversity of six major communities in ecological public-welfare forests of Zhejiang were analyzed used the sampling method. The six types are; shrubs contained more young pine trees （SMYPT）, shrubs contained more young evergreen broad-leaved trees （SMYET）, pine forest （dominated by pine trees, PF）, mixed coniferous and broad-leaved forests contained more pine trees （MFMPT）, mixed coniferous and broad-leaved forests contained fewer pine trees （MFFPT）, and evergreen broad-leaved forest （EGBLF）. In this paper, because evergreen broad-leaved forests are the zonal vegetation of Zhejiang, they are assumed as the target vegetation in the recovery processes. The results showed that the SMYPT and PF were usually distributed on degraded habitats in which the soil was thinner and poor. The woody layer in SMYPT and the under-tree layer in PF were mainly composed of sunny species, such as Rhododendron simsii, Loropetalum chinensis, Quercus fabri and so on. The dominated species of evergreen broad-leaved forest in Zhejiang were occasionally found in these 2 communities. So, it was infered that the rate of naturally restoration to the zonal climax vegetation （evergreen broad-leaved forests） would be very slow. The SMYET communities distribute on thicker soil, the dominant species include above species, and Schima superba, Cyclobalanopsis spp. , Castanopsis spp. were found frequently. In the woody layer their important values and degrees of presence were higher than those of the above shrubs. It will be restored quickly to the zonal climax vegetation. The species diversities were established through Gleason＇s, Shannon-Wiener＇s, Simpson＇s indices and the Pielou＇s evenness indices. In general, the indices of EGBLF are the highest. The indices of MFFPT were closed to those of EGBLF. The species diversities of SMYPT and PF were the lowest. The results also showed that species diversity decreases trends from under-tree layer, tree layer to herb layer. The investigation results showed that there are three restoration routes of ecological public-welfare forests in Zhejiang ： 1. shrubs→pine forests → mixed coniferous and broad-leaved forests→evergreen broad-leaved forests; 2. shrubs→ mixed coniferous and broad-leaved forests→evergreen broad-leaved forests; 3. shrubs→evergreen broad-leaved forests. It indicates that it is not necessary to go through the pine forest stage to recover to the evergreen broad-leaved forests in this area. The reasons which impacted the species diversity were analyzed in this paper. If the evergreen broad-leaved trees can be fostered and cultivated by supplements in better habitats, the vegetation will be recovered more quickly, and the ecological benefits of public-welfare forests can increase in a shorter time.