Invasive knotweed has greater nitrogen-use efficiency than native plants: evidence from a 15N pulse-chasing experiment
Invasive knotweed has greater nitrogen-use efficiency than native plants: evidence from a 15N pulse-chasing experiment
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DOI：
10.1007/s00442-019-04490-1
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发表时间：
2019-08
期刊：
影响因子：
2.7
通讯作者：
Madalin Parepa;A. Kahmen;R. Werner;M. Fischer;O. Bossdorf
中科院分区：
文献类型：
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作者：
Madalin Parepa;A. Kahmen;R. Werner;M. Fischer;O. Bossdorf
资源条件波动的栖息地对植物构成了特殊的挑战，它们通常偏爱一小部分物种，其中包括外来入侵者。这些物种必须拥有卓越的能力，通过更快的资源吸收或更高的资源利用效率来利用资源脉冲。我们在一项侵入性虎杖实验中解决了这个问题，虎杖是一种温带生态系统的有毒入侵者，众所周知，它会从营养波动中受益。我们使用稳定同位素来跟踪虎杖和五种本地竞争者之间的竞争对中氮脉冲的吸收和利用效率。我们发现氮脉冲确实促进了虎杖的入侵，这可以通过将吸收的额外氮转化为生物量的卓越效率来解释，而不是捕获过多的氮。因此，养分可用性的暂时增加可能有助于虎杖侵入自然环境，例如发生养分波动的河岸或氮污染的边缘和荒地。我们的实验表明，资源利用效率可以在资源条件波动的情况下推动入侵，而稳定同位素有助于理解这些过程。
Habitats with fluctuating resource conditions pose specific challenges to plants, and they often favor a small subset of species that includes exotic invaders. These species must possess a superior ability to capitalize on resource pulses through faster resource uptake or greater resource-use efficiency. We addressed this question in an experiment with invasive knotweed, a noxious invader of temperate ecosystems that is known to benefit from nutrient fluctuations. We used stable isotopes to track the uptake and use efficiency of a nitrogen pulse in competition pairs between knotweed and five native competitors. We found that nitrogen pulses indeed promoted knotweed invasion and that this is explained by a superior efficiency in turning the taken-up extra nitrogen into biomass, rather than capturing an overproportional share of the nitrogen. Thus, temporary increases in nutrient availability might help knotweed to invade natural environments, such as river banks or nitrogen-polluted margins and wastelands, where nutrient fluctuations occur. Our experiment shows that resource-use efficiency can drive invasion under fluctuating resource conditions, and that stable isotopes help to understand these processes.