Peperkorn Ralf, Werner Christiane, Beyschlag Wolfram
Department of Experimental and Systems Ecology, Universitätsstrasse 25, D-33615 Bielefeld, Germany.
Funct Plant Biol. 2005 Oct;32(10):933-944. doi: 10.1071/FP04197.
The phenotypic plasticity and the competitive ability of the invasive Acacia longifolia v. the indigenous Mediterranean dune species Halimium halimifolium and Pinus pinea were evaluated. In particular, we explored the hypothesis that phenotypic plasticity in response to biotic and abiotic factors explains the observed differences in competitiveness between invasive and native species. The seedlings' ability to exploit different resource availabilities was examined in a two factorial experimental design of light and nutrient treatments by analysing 20 physiological and morphological traits. Competitiveness was tested using an additive experimental design in combination with N-labelling experiments. Light and nutrient availability had only minor effects on most physiological traits and differences between species were not significant. Plasticity in response to changes in resource availability occurred in morphological and allocation traits, revealing A. longifolia to be a species of intermediate responsiveness. The major competitive advantage of A. longifolia was its constitutively high shoot elongation rate at most resource treatments and its effective nutrient acquisition. Further, A. longifolia was found to be highly tolerant against competition from native species. In contrast to common expectations, the competition experiment indicated that A. longifolia expressed a constant allocation pattern and a phenotypic plasticity similar to that of the native species.
评估了入侵物种长叶相思相对于本土地中海沙丘物种沙地半日花和海岸松的表型可塑性和竞争能力。具体而言，我们探讨了这样一种假设，即对生物和非生物因素的表型可塑性解释了入侵物种和本地物种之间观察到的竞争力差异。通过分析20个生理和形态特征，在光照和养分处理的双因素实验设计中检验了幼苗利用不同资源可用性的能力。使用加法实验设计结合氮标记实验测试了竞争力。光照和养分可用性对大多数生理特征的影响较小，物种间差异不显著。形态和分配特征出现了对资源可用性变化的可塑性，表明长叶相思是一种反应程度中等的物种。长叶相思的主要竞争优势在于，在大多数资源处理条件下其茎伸长率一直很高，且养分获取有效。此外，发现长叶相思对本地物种的竞争具有高度耐受性。与普遍预期相反，竞争实验表明，长叶相思表现出与本地物种相似的恒定分配模式和表型可塑性。
