爆发型种群铜锤草的数量动态研究

STUDY ON QUANTITATIVE DYNAMICS OF EXPLOSIVE POPULATION IN OXALIS CORYMBOSA

外来杂草入侵我国广大地区造成的严重危害迫切要求加大对外来杂草的研究 .针对重庆地区外来种铜锤草 (Oxalis corymbosa)危害严重的状况 ,通过不同生境下铜锤草种群在一个生长季的数量动态的研究 ,对其生态学特征及适应对策有了初步了解 ,结果表明 :1)铜锤草分株种群的死亡率的密度效应显著 ,高密度种群死亡率较高 ;2 )叶构件种群和留土鳞茎种群数量随季节变化有显著的负相关关系 ;3)铜锤草种群生物量结构及光合面积动态与环境之间的整合特征显著 ,表现为不同生境铜锤草种群生物量指标及叶面积指数增长速度和持续时间不同 。

Exotic weeds' invading has caused great harms in most regions of China, which requests urgently to enhance research on exotic weeds. In Chongqing where Oxalis corymbosa has brought about great hazard, the dynamics of its natural population is investigated. In the light of observation on population dynamics in different habitats, a preliminary comprehension is acquired about its ecological characteristics and adaptation strategies.The results are as follows. 1) Mortality rate is positively related to densities, that is, higher density population tends to have higher mortality rate. 2) Trade offs is significant between seasonal changes of leaves number and that of little bulbs remained in soil. 3) The dynamics of biomass structure and of leaf area is highly integrated with their habitats. The increasing rate and timing of biomass structure and of leaf area index are varied with habitats. Similar does the biomass allocation between photosynthetic and nonphotosynthetic structures.