High competitiveness of a resource demanding invasive acacia under low resource supply
High competitiveness of a resource demanding invasive acacia under low resource supply
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DOI：
10.1007/s11258-009-9625-0
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发表时间：
2009
期刊：
影响因子：
1.7
通讯作者：
C. Werner;Ulrich Zumkier;W. Beyschlag;C. Máguas
中科院分区：
文献类型：
--
作者：
C. Werner;Ulrich Zumkier;W. Beyschlag;C. Máguas
控制资源需求物种成功入侵低资源环境的机制仍然知之甚少。适应良好的本地物种在压力条件下往往被认为是上级竞争者。在这里，我们调查的竞争能力的资源要求alienAcacia longifolia，入侵营养贫乏的地中海沙丘，如在葡萄牙沿海地区。我们探讨的假设，干旱可能会限制入侵的因子竞争实验的外来入侵与两个本地物种的不同功能组（Halimium halimifolium，松树），在良好的浇水和干旱条件下。生物量，分配格局和N-吸收效率（通过15 N-标记）的变化表明了入侵者的干旱敏感性显着。然而，高效的干旱适应的本地物种没有提供一个竞争优势，在水分限制条件下。在水分充足的条件下，两种植物对外来入侵者的竞争优势在干旱条件下转化为正相互作用。此外，本地物种的低资源利用有利于A。在干旱条件下，长叶植物能够持续高氮吸收。因此，即使在低资源条件下，固氮入侵者也通过持续的高资源利用率来表达低可塑性。在群落中引入新的性状，如固氮和高资源利用，可能会促进A。通过物理环境的变化，即，入侵沙丘系统的水和养分循环，从而可能破坏本地植物群落内共同进化的相互作用。
Mechanisms controlling the successful invasion of resource demanding species into low-resource environments are still poorly understood. Well-adapted native species are often considered superior competitors under stressful conditions. Here we investigate the competitive ability of the resource demanding alienAcacia longifolia, which invades nutrient-poor Mediterranean sand dunes such as in coastal areas of Portugal. We explore the hypothesis that drought may limit invasion in a factorial competition experiment of the alien invasive versus two native species of different functional groups (Halimium halimifolium,Pinus pinea), under well-watered and drought conditions. Changes in biomass, allocation pattern, and N-uptake-efficiency (via15N-labeling) indicated a marked drought sensitivity of the invader. However, highly efficient drought adaptations of the native species did not provide a competitive advantage under water limiting conditions. The competitive strength ofH.halimifoliumtowards the alien invader under well-watered conditions turned into a positive interaction between both species under drought. Further, low resource utilization by native species benefitedA. longifoliaby permitting continued high nitrogen uptake under drought. Hence, the N-fixing invader expresses low plasticity by continuous high resource utilization, even under low resource conditions. The introduction of novel traits into a community like N-fixation and high resource use may promoteA. longifoliainvasiveness through changes in the physical environment, i.e., the water and nutrient cycle of the invaded sand dune system, thereby potentially disrupting the co-evolved interactions within the native plant community.