火烧对黄土高原典型草原地上植被和繁殖更新的影响  

Effects of fire on above-ground vegetation and offspring recruitment in a semiarid steppe on the Loess Plateau

作　　者：赵凌平[1,2] 白欣[1] 王占彬[1,2] 程积民[3] 谭世图 王清义[1,2] 

机构地区：[1]河南科技大学动物科技学院,河南洛阳471003 [2]河南省饲草饲料资源开发与畜禽健康养殖院士工作站,河南洛阳471003 [3]中国科学院水利部水土保持研究所,陕西杨凌712100

出　　处：《草业学报》2016年第1期108-116,共9页Acta Prataculturae Sinica

基　　金：国家自然科学青年基金项目(31302013);河南省教育厅科学技术研究重点项目(13A2302812013);河南科技大学博士启动基金项目(09001634)资助

摘　　要：火烧影响着草地植物种群的繁殖策略和形成过程,控制着群落的组成、外貌特征、动态变化和演替进程。本文通过对比黄土高原典型草原未火烧区和火烧区火后第一年地上植被特征、群落结构、物种组成和繁殖更新,探讨了黄土高原典型草原地上植被和繁殖更新对火烧的响应机制。结果表明,火烧显著降低了群落盖度、枯落物厚度与生物量,显著提高了群落的密度。火烧对物种丰富度影响不显著,却显著降低了4个物种多样性指数(Margalef指数、Shannon-Wiener指数、Simpson指数和Pielou指数)。火烧干扰明显改变了植物群落结构和物种组成。火烧显著提高了草地的繁殖更新密度和无性繁殖密度,而对有性繁殖密度和草地繁殖更新的物种丰富度影响不显著。火烧显著提高根茎型和分蘖型植物的密度,而对根蘖型、分枝型和匍匐型植物密度影响不显著。黄土高原典型草原是以多年生克隆植物为主的草原生态系统,地上植被的繁殖更新更依赖于无性繁殖。植物繁殖更新贡献高低与火烧无关,而与草地群落物种组成相关。There is an increased understanding of the role of fire in population dynamics,plant community structure and succession.However,few studies have examined the mechanism of the effect of fire on plant community structure and offspring recruitment.This study explored the short term responses of perennial grassland vegetation and offspring recruitment following fire on the Loess Plateau.The results showed that fire significantly reduced total cover,species diversity,litter thickness and litter biomass,and significantly increased community density;however it did not alter species richness.Fire exerted important effects on plant community structure and species composition in the short-term.Fire significantly increased asexual recruitment by clonal ramification,but had no effect on sexual recruitment through increased seedling numbers.Burnt grassland had a significantly higher density in tiller and rhizome offspring recruitment number than the unburnt grassland,however,recruitment from root suckers,branches and stolons did not differ significantly between the treatments.Our results indicate that asexual recruitment contributed more to vegetation regeneration of the perennial-steppe community than seedling recruitment.Lack of sexual recruitment is not related to fire management but to species composition.

关 键 词：火烧 典型草原 植被群落结构 繁殖更新 物种多样性 

分 类 号：S812[农业科学—草业科学]