单 位：
植被生态科学教育部重点实验室 长春130024;东北师范大学草地科学研究所;植被生态科学教育部重点实验室
关键词：
狼毒种群;年龄结构;根颈;存活曲线;种群更新
摘 要：
详细观察了内蒙古东部退化草原糙隐子草 (Cleistogenessquarosa)群落内狼毒 (Stellerachamae jasme)的根颈分枝形态及其生长发育特点 ,研究了狼毒种群的年龄结构 .结果表明 ,狼毒个体实际年龄为“类二叉分枝 (quasi dichotomousbranching)回数加 2” ;根颈上茎的残茬、枝痕和环状痕是确定根颈分枝回数的重要辅助特征 .重牧、过牧、极牧 3个放牧演替阶段内狼毒个体最大年龄依次为 15、16和 19龄 .8龄级个体数最多 ,其年龄比分别为 18 71%、2 4 2 0 %和 19 0 6 % .重牧阶段缺失 1和 2龄个体 ;过牧和极牧阶段均缺失 1龄个体 .狼毒种群年龄结构为“初始衰退型” ,存活曲线接近于“凸型”或DeeveyⅠ型 .老龄组 (13龄以上者 )个体数在重牧、过牧、极牧演替阶段分别占 4 83%、2 84 %和 14 0 2 % .随着放牧干扰的加剧 ,狼毒种群年龄结构呈现老龄化趋势
译 名：
Judging method of individual age and age structure of Stellera chamaejasme population in degraded steppe.
作 者：
XING Fu,GUO Jixun,WEI Chunyan(Institute of Grassland Science,Northeast Normal University,Changchun 130024,China)
关键词：
Stellera chamaejasme population, Age structure, Root crown, Survivorship curve, Population regeneration.
摘 要：
Based on the minute observation of branches morphology of root-crown of Stellera chamaejasme in Cleistogenes squarosa community and its growth characteristics,this paper studied the age structure of S.chamaejasme population,and an individual age judging method "the times of quasi-dichotomous branching plus two" was put forward for the first time.Remnant stubbles,branch trace,and annular trace on the root crown were regarded as important morphological features,and used to confirm the times of quasi-dichotomous branching.The results showed that the oldest individuals at three grazing succession stages (i.e.,heavy grazing,over grazing and extreme grazing) were 15,16 and 19 years old,respectively.Among all age classes,the numbers of eight years old individuals were the largest,and the age ratio was 18.71%,24.20% and 19.06%,respectively,at the different succession stages.There were no one- and two-year old individuals at heavy grazing stage,and no one-year old individuals at the other two grazing stages.The age structures of the populations were "early declining types",and the survival curves were similar to protuberant type or Deevey I type.The numbers of old age individuals (thirteen years old and more) at the three succession stages accounted for 4.83%,2.84% and 14.02%,respectively.The age structure of the population tended to aging with the increase of grazing intensity.
