古田山自然保护区地下芽植物多样性及其生物量分配策略

Diversity and biomass allocation of geophytes in Gutianshan National Nature Reserve,China

地下芽植物能够通过地下储存器官占据生境资源、储存营养物质等策略来获得生态优势,其地下储存器官多样性以及生物量分配策略,对地下芽植物物种组成以及生态系统功能产生重要影响。然而,以往研究多关注草地生态系统的地下芽植物,对森林地下芽植物的了解仍然缺乏。采集了古田山国家级自然保护区不同海拔分布的693个草本植物个体,分析了地下芽植物及其地下储存器官的类型与多样性,比较了地下芽植物与非地下芽植物的地上、地下各器官的绝对、相对生物量。结果显示:(1)地下芽植物的相对丰富度为69.1%,相对多度为88.2%。大多为根状茎植物,主要由禾本科、莎草科、堇菜科和蕨类植物组成。(2)除茎外,地下芽植物各器官的绝对生物量(叶:1.94g,根:0.65g,地上部分:2.0g,地下部分:4.1g)均大于非地下芽植物(叶:0.26g,根:0.13g,地上部分:0.68g,地下部分:0.13g)。(3)地下芽植物叶(0.40)与茎(0.14)的相对生物量小于非地下芽植物(叶:0.48,茎:0.35),地下部分相对生物量(0.56)大于非地下芽植物(0.17)。本研究表明,以根状茎植物为主的地下芽植物是古田山亚热带森林生态系统草本植物的主要构成者,且个体普遍较大,倾向于将生物量投资于地下器官。这些结果为认识地下芽植物的生态策略与功能以及草本植物群落管理提供了科学依据。

Underground storage organs enable geophytes to occupy habitat resources,to store nutrients,and thereby improve population fitness.The diversity of underground storage organs and their biomass allocation strategies have important impacts on the species composition and ecosystem function of geophytes.However,previous studies have mostly focused on geophytes in grassland ecosystems and the understanding of geophytes in forest is still lack.In this study,693 herbaceous plant individuals were collected from altitudinal gradients in Gutianshan National Nature Reserve,Zhejiang Province,China.The types and diversity of geophytes and their underground storage organs were categorized and the absolute and relative biomass of each aboveground organ and belowground organ between geophytes and non-geophytes were compared.The results showed that:(1)the relative richness of geophytes was 69.1%and the relative abundance was 88.2%.Most were rhizomatous plants,mainly composed of Gramineae,Cyperaceae,Violaceae and ferns.(2)Except for stems,the absolute biomass of all organs of geophytes(leaves:1.94g,roots:0.65g,above:2.0g,below:4.1g)was greater than that of non-geophytes(leaves:0.26g,roots:0.13g,above:0.68g,below:0.13g).(3)The relative biomass of leaves(0.40)and stems(0.14)of geophytes was less than that of non-geophytes(leaves:0.48,stems:0.35)and the relative biomass of belowground parts of geophytes(0.56)was greater than that of non-geophytes(0.17).It found that geophytes which were mainly rhizomatous plants were the main constituents of herbaceous plants in the subtropical forest ecosystem of the Gutianshan Reserve,and were generally larger in biomass and tended to invest their biomass in belowground organs.These results provide a scientific basis for understanding the ecological strategies and functions of geophytes and the management of herbaceous communities in subtropical forests.