Studies on the dynamic structure of persistent and productive pasture ecosystems

持久性和生产性牧场生态系统动态结构研究

基本信息

批准号：
09306018
负责人：
YAMAMURA Yasuo
金额：
$ 6.91万
依托单位：
IBARAKI UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

(1) Analyses of biological factors of persistency : In order to clarify biological factors responsible for persistency of grasslands, adaptive strategy of major temperate grass species was investigated in relation to tradeoff between growth performance and stress tolerance. The extent of intraspecific genetic variation in adaptive strategy was also examined and discussed in relation to grassland managements. To know the reason for instability of pasture vegetation we conducted some manipulations on some pastures. Selective grazing was the main reason for instability of pasture vegetalion.(2) Ecology of grassland species : Ecological aspects of reproduction were studied for some pasture plants. Some properties of clonal reproduction in Trifolium repens and the condition for consistence of wind pollination and extended flowering in Anthoxanthum odoratum were shown. The leaf dynamics of bracken in semi-natural grassland was investigated. The pattern of leaf emergence was associated with cumulative air temperatures and seasonal change of photosynthetic activity.(3) Modeling of the vegetation dynamics and distribution pattern : A model of canopy dynamics of a bahia grass sward was constructed, dealing with a tiller as a basic unit. This model enables us to examine the effects of sward management and meteorology on the dynamics of tiller density, herbage mass, sward height and leaf area index. In semi-natural grasslands in Tochigi Prefecture, small-scale spatial heterogeneity in plant species community was measured based on a new method. The relationship between the spatial heterogeneity and the species diversity was expressed by a model.

（1）对持续性生物学因素的分析：为了澄清负责草原持续性的生物学因素，研究了主要温带草种的自适应策略，这些策略与生长绩效和压力耐受性之间的权衡有关。还检查了与草地管理有关的自适应策略中种内遗传变异的程度。要了解牧场植被不稳定的原因，我们就某些牧场进行了一些操纵。选择性放牧是牧场植物植物不稳定的主要原因。（2）草地的生态：研究了某些牧场植物的生殖方面。显示了三叶量再生产中克隆繁殖的某些特性，以及在气候中的风粉和延长开花的状态。研究了Bracken在半天然草原中的叶动力学。叶片出现的模式与累积的空气温度和光合作用活动的季节变化有关。（3）建造了植被动力学和分布模式的建模：构建了巴伊亚草草的树冠动力学模型，构建了蒂勒作为基本单位。该模型使我们能够检查草间管理和气象对分er密度，草药质量，草高和叶子面积指数动态的影响。在Tochigi县的半天然草原中，根据一种新方法测量了植物物种社区中的小规模空间异质性。空间异质性与物种多样性之间的关系由模型表达。