南亚热带森林土壤种子库与地上植被的组成特征及其关系

Composition of vegetation and soil seed bank in low subtropical forests and their relationship

该文通过在鼎湖山自然保护区设立的固定植物样带,研究地上植物组成数量特征和土壤种子库的关系.结果表明:①该植物样带共有木本植物93种,其中,乔木60种,灌木33种;草本植物30种,其中,蕨类植物12种.②植物样带土壤种子库出现木本植物36种,其中,乔木11种,灌木25种.土壤种子库木本植物种子数量平均183粒m2,其中,灌木平均数量为162粒m2,乔木平均数量为21粒m2,灌木在土壤种子库中的数量远远高于乔木;出现草本植物13种,其中蕨类植物3种,草本植物种子数量平均为215粒m2.③土壤种子库与地上优势种相关性比较:草本>灌木>乔木.土壤中,草本植物种子数量以先锋种为主;乔木中,演替中间种的种子数量占优;灌木中,演替先锋种种子数量占优.④地上植被和土壤种子库之间的关系通过将森林群落植物划分为不同的生活型进行比较,灌木的Sorensen系数(0.54)>草本(0.32)>乔木(0.28).如果将地上植物按径级除去幼树,乔木的Sorensen系数为0.47.从共有种百分比来看,乔木为91%,灌木为65%,草本植物为50%.

A permanent sample transect of plant communities was established on Dinghushan Mountain to study the relationship between the size of the vegetation composition above-ground and the soil seed bank. The results were as follows： 1） ninty-three woody species were present in the forests transect and of which 60 were trees and 33 shrubs; as well, 30 species of herbage appeared under the canopy and of which 12 were ferns; 2） thirty-six species of woody plants were found in the soil seed bank, including 11 tree species and 25 shrub species. The average woody seed density was 183 grains/m^2 ; for shrubs the density was 162 grains/m^2 and for trees 21 grains/m^2. The number of seeds of shrubs was far more than that of trees. In addition, thirteen species of herbage were identified in soil seed bank samples including three species of fern and their average seed density was 215 grains/m^2 ; 3） the pertinent comparison of species predominance between soil seed bank and above-ground vegetation was： herbage 〉 shrub 〉 tree. In the soil seed bank, most herbage seeds were pioneer species; seeds of middle succession species were dominant in trees and the seeds of pioneer species were dominant in shrubs; 4） to study the relationship between vegetation and soil seed bank, species in plant communities were divided into three groups by life forms. Result was that the Sorensen coefficient of shrub 0.54 〉 herbage 0.32 〉 tree 0.28. If we omit saplings according to DBH, the Sorensen coefficient for trees increases to 0.47. The following percentages of species were present both above ground and in the soil seed bank： tree 91%, shrub 65% and herbage 50%.