Gilbert Benjamin, Wright S Joseph, Muller-Landau Helene C, Kitajima Kaoru, Hernandéz Andrés
Department of Botany, University of British Columbia, Vancouver, Canada.
Ecology. 2006 May;87(5):1281-8. doi: 10.1890/0012-9658(2006)87[1281:lhtitt]2.0.co;2.
It has been hypothesized that tropical trees partition forest light environments through a life history trade-off between juvenile growth and survival; however, the generality of this trade-off across life stages and functional groups has been questioned. We quantified trade-offs between growth and survival for trees and lianas on Barro Colorado Island (BCI), Panama using first-year seedlings of 22 liana and 31 tree species and saplings (10 mm < dbh < 39 mm) of 30 tree species. Lianas showed trade-offs similar to those of trees, with both groups exhibiting broadly overlapping ranges in survival and relative growth rates as seedlings. Life history strategies at the seedling stage were highly correlated with those at the sapling stage among tree species, with all species showing an increase in survival with size. Only one of 30 tree species demonstrated a statistically significant ontogenetic shift, having a relatively lower survival rate at the sapling stage than expected. Our results indicate that similar life history trade-offs apply across two functional groups (lianas and trees), and that life history strategies are largely conserved across seedling and sapling life-stages for most tropical tree species.
有一种假说认为，热带树木通过在幼年生长和生存之间进行生活史权衡来划分森林光照环境；然而，这种权衡在不同生命阶段和功能组中的普遍性受到了质疑。我们使用22种藤本植物和31种树的一年生幼苗以及30种树的幼树（10毫米 < 胸径 < 39毫米），对巴拿马巴罗科罗拉多岛（BCI）上的树木和藤本植物的生长与生存之间的权衡进行了量化。藤本植物表现出与树木类似的权衡，两组在作为幼苗时的生存和相对生长率方面都呈现出广泛重叠的范围。在树种中，幼苗阶段的生活史策略与幼树阶段的策略高度相关，所有树种的生存都随尺寸增加。30种树中只有一种表现出统计学上显著的个体发育转变，其幼树阶段的存活率低于预期。我们的结果表明，类似的生活史权衡适用于两个功能组（藤本植物和树木），并且对于大多数热带树种来说，生活史策略在幼苗和幼树生命阶段基本保持不变。
