摘要
竹子生活史中具有不同寻常的开花特性,即不同种类的竹子以不同的周期(3-120年)大范围同步开花死亡。到目前为止,除了几个假说之外,对竹子开花的生理与遗传因子尚缺乏实质性的了解。假说之一为"外因说",认为竹子开花是由降雨等外源因素对生理过程的影响所控制。另一个为Janzen的"摄食饱和"假说:当某种竹子零星开花时,生境内的种子摄食者便食尽种子;只有当竹子的结籽数量大于种子摄食者的摄食饱和度时,种群才能有性更新,如此反复就形成竹子的同步开花。在古代中国,戴凯把竹子开花的周期性开花归纳为"竹六十年亦易根,易根辄结实而枯死",他的观点为竹子开花的解释提供了生态视野。竹子在其漫长的营养生长中,不断地从土壤中吸取营养,并将这些营养物质转移到地下茎予以储存,随着储存的累积,土壤与竹子植株的营养平衡便被打破。这样就会导致竹子种群的生态变化与开花。
The life history of many bamboo species is characterized by an unusual flowering habit. They often flower and die simultaneously over wide areas at intervals ranging from a few years to up to 120 years, depending on the species. Physiological and genetic factors involved in the induction of such flowering are unknown to date, but several hypotheses exist concerning the causes of flowering. One explanation is that of external controls on physiological processes by available resources such as rainfall. Another is a widely accepted theory proposed by Janzen, which assumes that irregular fruiting cycles are sufficient disequilibria to inhibit seed predators from maintaining populations large enough to decimate a ' mast year' of fruiting. In ancient China, Dai Kai concluded the periodical flowering of bamboo plants as 'the bamboo relieves its roots (rhizomes) after 60 years' growth and dies off after seeding' which provided an ecological view on the gregarious flowering of the bamboo. It may indicate that during a long vegetative period the bamboo absorbs nutrients from the soil and deposits them in its rhizomes. As the time being, the nutrient balance between soil and the bamboo plants may break down, which resulting ecological changes and flowering of the bamboo population.
出处
《世界竹藤通讯》
2004年第4期21-23,共3页
World Bamboo and Rattan
关键词
开花特性
竹子
摄食
土壤
种子
花时
枯死
寻常
假说
死亡
<Keyword>bamboo flowering, relieving rhizome, nutrient balance, clonal population
