不同坡向荩草构件的权衡关系

Abstract

权衡关系是植物生活史对策理论的基础，研究不同坡向植物构件的权衡关系对理解植物在不同生境下的表型可塑性具有重要意义。本研究选取济南市长清区琵琶山不同坡向的典型植物--荩草(Arthraxon hispidus)为研究对象，分析了不同坡向影响下荩草种群构件间的关系。结果表明：坡向是影响荩草构件权衡的重要地形因子，从构件形态看，南坡的荩草相比北坡来说更倾向于茎叶生物量的增长，北坡的荩草则表现出以更大的茎节间长；从异速生长关系看，叶宽、叶面积和株高在各坡向不具有共斜率，采取不同的分配策略，其它构件在各坡向具有共斜率，只是在分配方面略有倾向。不同坡向荩草构件的权衡关系反映了异质生境中资源多重竞争下荩草生物量的分配机制和提高种群适应性的种群更新策略。 Trade-off is the basis of plant life history strategy theory. It’s very important to study the trade-off among plant modules in different aspects for understanding the phenotypic plasticity of plants under different habitat conditions. In this study, we selected one common plant-Arthraxon hispidus, on Mount Pipa in Changqing district, Jinan city as the focal species. We studied the relationship between modules of A. Hispidus populations under the effects of different aspects. The results showed that aspect had a significant effect on the trade-off of modules of A. Hispidus populations. Biomass of stems and leaves of plants on south slope was higher than those on the north slope. While, A. hispidus on the north slope improved the internode length adapting to the environment. The allometric relationships of leaf width, leaf area and height vs. plant biomass were different on different slopes, which were affected by different aspects of slopes. While the allometric relationships of other modules vs. plant biomass were not affected by different aspects of slopes. The trade-off between different modules showed that A. Hispidus can choose effective biomass allocation and regeneration strategies to survive the multiple resource competitions in heterogenous habitats.