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Species diversity in grassland plant communities

草原植物群落的物种多样性

基本信息

批准号：
08044192
负责人：
HARA Toshihiko
金额：
$ 4.74万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08044192/
关键词：
clonal growth DNA-RAPD mountain grassland species diversity maintenance mechanism of a population Krkonose Mountains in the Czech Republic population dynamics genetic structure of a population チェコ共和国Xrkonose山クローンシュート生長動態遺伝的構造 /

项目摘要

The dynamics of growth, mortality, reproduction and the size and spatial distributions of genets of Anthoxanthum alpinum, Deschampsia flexuosa, Nardus stricta, Festuca rubra were investigated in a mountain grassland of the Krkonose Mountains in the Czech Republic. Based on the field and experimental results, maintenance mechanisms of species and genetic diversity were theoretically investigated. We extracted DNA from about 2000 sampled leaves and identified size and spatial position of each individual genet by using a DNA-RAPD method. We found 450-750 genets per 1mィイD12ィエD1 of Festuca rubra. Its mean genet size was about 22 cmィイD12ィエD1. The clonal growth rate of Festuca rhizomes was 0.2-0.3/year. The mortality rate of shoot was also 0.2-0.3/year. It is almost impossible to measure genet natality in a non-destructive way. Therefore, we developed a new model to estimate genet natality from the above-mentioned demographic parameters. It was suggested that the Festuca population can persist stably if the genet natality rate is 4-10genets/1mィイD12ィエD1 year. The clonal growth and mortality rates of Festuca shoots showed only small variations in the field. Genet natality may be most greatly affected by environmental variations. When the clonal growth and mortality rates of Festuca shoots are in the range of the values given above, the Festuca shoot population is stable even if the genet natality is greatly varied due to environmental variations. It was also revealed that genetic structure played a more important role than competition between species for the dynamics of grassland plant community studied here.

在捷克共和国克尔科诺斯山脉的山地草原上，对高山花黄花、屈曲花、松柏、羊茅的生长、死亡率、繁殖动态以及基因的大小和空间分布进行了调查。基于实地和实验结果，从理论上研究了物种和遗传多样性的维持机制。我们从大约 2000 个叶子样本中提取了 DNA，并使用 DNA-RAPD 方法确定了每个基因的大小和空间位置。我们发现每 1mィイD12ィエD1 羊茅有 450-750 个基因。其平均基因大小约为 22 cmィイD12ィエD1。羊茅根茎的克隆生长率为0.2-0.3/年。芽死亡率也为0.2-0.3/年。以非破坏性的方式测量基因出生率几乎是不可能的。因此，我们开发了一种新模型，根据上述人口统计参数来估计基因出生率。研究表明，基因出生率为4-10基因/1mィイD12エD1年，羊茅种群可以稳定持续存在。羊茅芽的克隆生长和死亡率在田间仅表现出很小的变化。基因出生率可能受环境变化的影响最大。当羊茅幼苗的克隆生长率和死亡率在上述数值范围内时，即使基因出生率因环境变化而发生很大变化，羊茅幼苗种群仍保持稳定。研究还表明，对于本文研究的草原植物群落动态而言，遗传结构比物种之间的竞争发挥着更重要的作用。