三年生植物

Flooding,as a kind of disturbance events,occurred with higher and higherfrequency over the world.To investigate the effects of flooding disturbance ongrassland vegetation and the soil,a comparatively thorough study was conducted onAneurolepidium chinense grassland in Songnen plain,Northeast China.The studysite was located in Sanjiadian National Rangeland in the territory of Da'an city,Jilirprovince,which was partly flooded in 1998.On the study site,Several transectssubjected to different flooding durations and intensities were designed for thecomparative study among them on such aspects as vegetation characteristics,seedbanks,vegetative propagation of rhizomatous plants,distribution patterns ofpopulations,interspecific relations,and physio-chemical properties of soil.Theresults were as follows:(1)Of the functional group composition of the vegetation,with the elongation of the flooding duration or the increase of flooding severity,theratio of hygric and hygro-mesic plants increase,while that of mesic and mesoxericplants decrease,of Therophytes changed unimodally,of Geophytes increased,whileof Hemicryptophytes decreased.

为弄清草地植被及其土壤环境对水淹干扰的响应，在松嫩平原羊草草地1998年部分遭受水淹的吉林省大安市三家甸子草场内设置了经历不同水淹干扰持续时间和不同水淹强度的样带，并在这些样带之间从植被特征、种子库特征、根茎植物的营养繁殖性能、种群分布格局、种间关系及土壤的理化性质等多个方面展开对比研究，主要结果如下：(1)在植被的功能群组成中，随干扰强度的增加和水淹干扰持续时间的延长，湿生、湿中生类植物功能群的优势度比例基本上是逐渐增加的，中生、中旱生类植物功能群的优势度比例则逐渐减小，而一年生植物的优势度比例呈单峰型变化，地下芽植物比例增加，地面芽植物比例减小。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。