Spatiotemporal dynamics of the clone of white clover in a grazed sward

在放牧草地上研究了白三叶单株无性系的时空动态。首先，开发了测量和描述白三叶克隆生长的新技术。利用这些技术，在多年生黑麦草白色三叶草草地上对目标克隆的克隆生长进行了两年的监测。结果表明：(1)该无性系在夏季至秋末分布较广，但在冬季至初夏其体型较小。这种凹陷是由于融化-结霜循环造成的。(2)无性系的碎片化发生在冬季至早春。有根和有枝的模块很可能是分离的部位。(3)观察到挤压现象。(4)找出了分枝策略。(5)评价了黄牛落叶的程度和方式。未被食用的健康叶片数量较少。它们围绕着匍匐茎的顶端放置。(6)在集约化放牧草地上，白三叶无性系的落叶胁迫一致严重。(7)落叶胁迫对白三叶无性系危害较大，并促进其大小的变化，具有较高的死亡风险。

Spatiotemporal dynamics of a single clone of white clover was examined in a grazed sward. Firstly, new techniques were developrd to measure and describe the clonal growth of white clover. Using the techiques, clonal growth of the target clone was monitored for two years in a perennial ryegrass-white clover sward. Following results were obtained : (1) The clone spreaded widely in summer to late-autumn but decreased its size in winter to early-summer. This depression was due to the thawing-frosting cycle. (2) Fragmentation of the clone occurred in winter to early-spring. Modules with roots and branches were likely to be sites for the separation. (3) Crush phenomenon was observed. (4) Branching strategy was found out. (5) The extent and pattern of defoliation by cattle were assessed. Number of healthy leaves which were not eaten was small. They placed near around the apex of stolons. (6) In an intensively grazed sward, defoliation stress to white clover clones was uniformly severe.(7) Defoliation stress gives them heavy damage and promotes the changes in size, resulting in high mortality risk.