Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.
PLoS One. 2012;7(2):e31596. doi: 10.1371/journal.pone.0031596. Epub 2012 Feb 16.
Invasive exotic plant species are often expected to benefit exclusively from legacy effects of their litter inputs on soil processes and nutrient availability. However, there are relatively few experimental tests determining how litter of exotic plants affects their own growth conditions compared to congeneric native plant species. Here, we test how the legacy of litter from three exotic plant species affects their own performance in comparison to their congeneric natives that co-occur in the invaded habitat. We also analyzed litter effects on soil processes. In all three comparisons, soil with litter from exotic plant species had the highest respiration rates. In two out of the three exotic-native species comparisons, soil with litter from exotic plant species had higher inorganic nitrogen concentrations than their native congener, which was likely due to higher initial litter quality of the exotics. When litter from an exotic plant species had a positive effect on itself, it also had a positive effect on its native congener. We conclude that exotic plant species develop a legacy effect in soil from the invaded range through their litter inputs. This litter legacy effect results in altered soil processes that can promote both the exotic plant species and their native congener.
入侵的外来植物物种通常被认为仅受益于其凋落物输入对土壤过程和养分供应的遗留效应。然而，很少有实验测试确定外来植物的凋落物如何与其在入侵栖息地中共同存在的同种本地植物物种相比，影响它们自身的生长条件。在这里，我们测试了三种外来植物物种的凋落物的遗留效应对它们自身表现的影响，与在入侵栖息地中共同存在的同种本地植物物种进行了比较。我们还分析了凋落物对土壤过程的影响。在所有三种比较中，来自外来植物物种的凋落物的土壤具有最高的呼吸速率。在三种外来-本地物种比较中的两种中，来自外来植物物种的凋落物的土壤中无机氮浓度高于其本地同属种，这可能是由于外来种的初始凋落物质量较高。当外来植物物种的凋落物对自身有积极影响时，它也对其本地同属种有积极影响。我们的结论是，外来植物物种通过凋落物输入在入侵范围内的土壤中形成了一种遗留效应。这种凋落物的遗留效应导致土壤过程发生变化，从而促进了外来植物物种及其本地同属种的生长。
