摘要
调查研究西凉湖的刺苦草（V.spinulosa）在不同水深下的生长和繁殖策略,试图弄清是否水位的变化影响刺苦草的繁殖策略,进而影响刺苦草在湖泊中的分布情况.研究结果表明：在水深1.4~2.2 m的范围内,刺苦草有性繁殖体的生物量、有性繁殖体的收获系数和繁殖体个数都随水深的增加而减少.水深2 m以下,随着水深的增加,刺苦草的地上生物量和地下生物量逐渐增加;水深超过2 m后,生物量显著减少,刺苦草的有性繁殖受限.随着水位的变化,有性繁殖体的投资比率发生变化,从水深1.4 m的2.77%±0.96%到水深2 m的0.13%±0.22%;而无性分株繁殖方式水深2 m以下没有显著差异.当水深超过2 m时,无性分株数明显减少,约为492株/m2.水深不影响刺苦草的根冠比.
Few researches have showed whether reproductive strategy changed due to water depth gradient, particularly patterns of sex allocation. So a field study was undertaken to investigate the growth and reproduction response of V. spinulosa to water depth gradient in the Xiling Lake. We wanted to elucidate how the growth and reproduction of V. spinulosa responsed to water depth gradient,and whether the distribution of V. spinulosa in the Xiling Lake were affected by water depth gradient. Based on our field investigation, we estimated the above-ground and below-ground biomass of V. spinulosa gradually increased with the increase of water depth when the water depth was less than 2 meters, the biomass of V. spinulosa decreased significantly when the water depth was more than 2 meters, as well as the sexual reproduction strategy of V. spinulosa was limited by the more than 2.0 meters water depth. Resource allocation ratios of sexual propagules ranged from 2.77% ± 0.96% in 1.4 meters low-water environment to 0.13% ± 0.22% in 2 meters deep-water environment with the change of water depth. Number of vegetative ramets changed less significantly in the below 2 meters water depth, while it decreased significantly to 492 ramets per square meter in more than 2 meters deep-water environment. There were no significant changes in the ratios between above-ground biomass and below-ground biomass.
出处
《江西师范大学学报（自然科学版）》
CAS
北大核心
2007年第2期156-160,共5页
Journal of Jiangxi Normal University(Natural Science Edition)
基金
国家重点基础研究发展规划项目(2002CB412300)
中国科学院知识创新工程重要方向项目(KSCX2-1-10)
国家自然科学基金(03050351)资助项目
关键词
刺苦草
水深
生长
繁殖策略
Vallisneria spinulosa
water depth gradient
growth
reproduction strategy
