摘要
濒危植物是全球生物多样性的重要组成部分,为了弄清中亚热带地区不同生长型濒危乔木树种的竞争模式及其机制,研究了江西九岭山国家级自然保护区毛红椿和南方红豆杉的种内与种间竞争差异。结果表明:阳性落叶树种毛红椿种群的竞争压力主要来自于同种个体,种内竞争指数占总竞争指数的66.4%,耐阴常绿树种南方红豆杉种群主要受种间竞争的影响,种间竞争指数占总竞争指数的68.7%。2种濒危植物受到的种内、种间以及总竞争强度均随着林木径级的增大而逐渐减小,表明竞争压力由幼林向成熟林逐渐降低。在生长过程中,毛红椿以种内竞争引起的自疏作用为主导,南方红豆杉则由种间竞争引起的他疏作用为主导。毛红椿和南方红豆杉种群在更新过程中,小径级个体都要经历强度较大的种内或种间竞争选择才能发育为成树。由于主要竞争压力的来源差异,对于生活在中亚热带同一区域内不同生长型的濒危植物应该采取不同的生物多样性保育措施。
Endangered plant species are an important part of global biodiversity.To understand the competition patterns and mechanisms of endangered tree species from plant growth forms in the middle subtropical forest ecosystems,we examined the differences in intra-and inter-specific competitions between Toona ciliate var.pubescens(an intolerant of shade,deciduous species)and Taxus chinensis var.mairei(a tolerant of shade,evergreen species)in the Jiulingshan National Nature Reserve,Jiangxi Province.The results showed that intra-specific competition was dominant in the T.ciliate var.pubescens population,accounting for 66.4%of the total competition intensity.In contrary,the competitive intensity of T.chinensis var.mairei was dominated by the inter-specific competition,which accounted for 68.7%of the total competition intensity.The intra-and inter-specific competition intensity of both species decreased gradually with increasing tree diameter,indicating that competitive pressure was prevalent in small trees.T.ciliate var.pubescens was mainly affected by self-thinning due to intra-specific competition,whereas T.chinensis var.mairei was dominated by alien-thinning due to inter-specific competition.The small individuals of both species could develop into mature stage only after experiencing intense competitive selection during stand regeneration.Considering the substantial difference in the sources of competition pressures,different biodiversity conservation measures should be taken for the two endangered species with contrasting growth forms in the middle subtropical regions.
作者
徐佳文
石福习
张朝晖
万松泽
吴盼盼
刘姗姗
毛瑢
XU Jia-wen;SHI Fu-xi;ZHANG Chao-hui;WAN Song-ze;WU Pan-pan;LIU Shanshan;MAO Rong(Key Laboratory of State Forestry and Grassland Administration on Forest Ecosystem Protection and Restoration of Poyang Lake Watershed,College of Forestry,Jiangxi Agricultural University,Nanchang 330045,China;Jiulingshan National Nature Reserve in Jiangxi Province,Jing9 an 330600,Jiangxi,China)
出处
《应用生态学报》
CAS
CSCD
北大核心
2020年第1期1-8,共8页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(41867007,41601056,31570479)资助~~
关键词
濒危植物
植物生长型
生物多样性保育
竞争
亚热带森林
endangered plant
plant growth form
biodiversity conservation
competition
subtropical forest
