摘要
采用野外调查和室内萌发相结合的方法,对桂西北典型喀斯特峰丛洼地刈割、开垦和火烧3种不同人为干扰方式下草丛群落的土壤种子库进行了比较研究。结果表明:13种不同干扰方式草丛群落土壤种子库密度存在显著差异,其种子密度大小为:刈割群落>开垦群落>火烧群落;2刈割、开垦、火烧干扰草丛种子主要分布在0～2cm(67%)、2～5cm(55%)、5～10cm(37%)的土层中;3刈割群落土壤种子库中乔、灌、草生活型的物种比例大于开垦和火烧干扰群落;43种不同干扰方式草丛群落土壤种子库的丰富度指数、Shannon-Wiener指数和Simp-son指数的大小顺序均为:刈割群落>开垦群落>火烧群落,同群落物种数变化趋势一致,与生态优势度呈相反趋势;均匀度指数大小顺序为:刈割群落>火烧群落>开垦群落。5从土壤种子库与地面植被物种组成相似性系数来看,刈割群落和开垦群落相似性系数较大,而火烧群落地上与地下物种组成有较大区别,相似性系数为0.296。研究结果表明,刈割干扰相对开垦和火烧更有利于喀斯特地区草丛群落土壤种子库的维持与保护。
The southwest China karst area is one of the eco-environmental fragile areas in China. Human disturbances have significant effect on the distribution characteristics and species diversity of the soil seed bank in degraded karst region. Comparative study on hassock community soil seed bank under three kinds of human disturbance is carried out in northwest Ouangxi typical karst peak-cluster depression by means of sampling and germination. There existed 3 levels of disturbed type community, i. e. , mowing community （MC）, reclamation community （RC）, and fired community （FC）. The main conclusions are as follows： ①Hassock community soil seed bank under three different kinds of disturbance has significant difference. The sequence of seed density in soil seed banks is MC〉RC〉FC; ②The maximum soil seed density of mowing community,reclamation community and fired community distribute in 0-2cm （67%）, 2-5cm （55%） and 5-10cm （370//00） soil layer respectively. ③Proportional composition of life forms of mowing community is superior to reclamation and fired community. ④Richness index, Shannon-Wiener index and Simpson index in hassock communities under three different disturbances are ranked： MC〉RC〉FC, which shows similar change tendency to number of community species, and has an opposite tendency with ecological dominance. The order of evenness index is MC〉FC〉RC. ⑤The similarity coefficient in both soil seed bank and above-ground vegetation in the mowing community and reclamation community are more than that in the fired community. The research results show that light disturbance is relatively most beneficial to maintaining and protecting soil seed bank in karst region. Therefore, it could be very important that human disturbances are scientifically rational guidance for the restoration and reconstruction of degraded karst ecosystem.
出处
《中国岩溶》
CAS
CSCD
北大核心
2008年第4期309-315,共7页
Carsologica Sinica
基金
国家重点基础研究发展计划(973)(2006CB403208)
中国科学院西部行动计划(KZCX2-XB2-08)
关键词
人为干扰
土壤种子库
草丛群落
喀斯特
桂西北地区
human disturbances
soil seed bank
hassock community
karst
northwest Guangxi
