摘要
入侵成功的外来种铜锤草 (Oxaliscorymbosa)表现出爆发型的分布格局 .为探索该物种对异域环境的适应性 ,以实验手段对不同人工胁迫环境下一个生长季的铜锤草生活史特征进行了比较 .结果表明 :水分胁迫促使植株株型紧缩 ,叶片周转率提高 ,生物质量累积下降 ;遮阴条件显著降低叶的周转率 (P <0 .0 0 1) ,生物质量累积下降 ;竞争条件下植株株型高大 ,生物质量累积增加显著 (P <0 .0 0 1) ,表现出形态可塑性 .水分胁迫下植株生长缓慢 ,增长期缩短 ,最大生长量显著降低(P <0 .0 0 1) ;遮阴条件下增长期缩短 ,叶面生长速度提高 ,而高生长速度有所下降 ;竞争促进生长 ,生长期和生长速度均有明显提高 .相对而言 ,水分胁迫下种群存活率提高 ,无性繁殖率降低 ,且水分胁迫越严重无性繁殖率越低 ;遮阴促使种群快速完成生活史 ,种群存活率和无性繁殖率均降低 ;竞争条件下存活率有所下降而无性繁殖率增加 ,种群存活和繁殖之间的颉抗关系表现明显 .胁迫环境下 。
The distribution pattern of the introduce, Oxalis corymbosa , a successful invasion species, is explosive. To understand its adaptation capacity in the exotic region, a comparison of the life history characteristics in one growth season under stress conditions was made by experiment. The results are as follows. The plant shrunk, leaf turnover rate increases and biomass accumulation decreases under water stress. The leaf turnover rate and biomass accumulation decrease under the shadow condition. While the plant size enlarged, the biomass accumulation notably increases under the competition condition. These phenomenons represent its morphological plasticity. Its strategy of growth is represented by the slow growth, shortened growing period, the notable decrease of maximum increment under water stress; shortened growing period, the accelerated growth of leaf area and the slowdown of height growth under the shadow condition; significantly lengthened growth period and the accelerated growth of leaf area and height under the competition condition. Comparably, the survival rate increases and the vegetative multiplication rate decreases under the water stress condition, and the heavier of the stress, the lower of the vegetative multiplication rate would be; the life span shortened, the survival rate and vegetative multiplication rate decreases under the shadow condition; the survival rate decreases but the vegetative multiplication rate increases under the competition condition. The trade off between the rates of population survival and reproduction is obvious. In general, the population fitness is different under different stress condition.
出处
《北京师范大学学报（自然科学版）》
CAS
CSCD
北大核心
2004年第3期369-374,共6页
Journal of Beijing Normal University(Natural Science)
基金
国家自然科学基金重点资助项目(3 93 3 0 0 50 )
国家自然科学基金资助项目(3 0 2 70 2 5 4)
国家"九七三"计划资助项目(2 0 02CB111507
G2 0 0 0 0 4680 2)
教育部博士点基金资助项目(2 0 0 0 0 0 2 716)
关键词
爆发型种群
生活史对策
生态适应
适合度
生存曲线
explosive population
life history strategy
ecological adaptation
fitness
survival curve
