The National Field Station of Freshwater Ecosystem of Liangzi Lake, Department of Ecology, College of Life Sciences, Wuhan University, Wuhan, P.R. China.
PLoS One. 2018 Jun 20;13(6):e0199478. doi: 10.1371/journal.pone.0199478. eCollection 2018.
Climate change, especially warming temperatures, may increase invasion and modify the ecological impacts of invasive species by enhancing their ability to compete. To test the effects of warming on invasive plants, a mesocosm experiment was conducted to study competition between the invasive plant Egeria densa and the native hygrophyte Sparganium angustifolium under simulated warming conditions in a greenhouse. These two species were grown in monoculture (no competitor control) or mixed culture (competitor control) for two months under different temperature conditions (warming treatment or no-warming treatment). In S. angustifolium, the higher temperatures led to a shorter root length and significantly increased the aboveground traits of ramets, the total biomass, and the RGR (relative growth rate) but had no effect on the aboveground traits of genets. Growth in mixed culture significantly decreased the S. angustifolium ramet height under warmer conditions and significantly reduced the ramet root length, ramet number, genet biomass, root-to-shoot ratio and RGR of S. angustifolium under natural temperature conditions. All the morphological, biomass and growth traits of E. densa except for the root-to-shoot ratio were significantly increased by the warmer temperatures and decreased by growth in mixed culture. The RCI and RII of E. densa in both the no-warming and warmer environments were two and three times greater than those of S. angustifolium, whereas the ACI values for the two species were similar. Thus, S. angustifolium was a better competitor than E. densa under both temperature conditions. These results suggest that although the superior competitive ability of native species can inhibit E. densa growth, the performance of this species will be enhanced under future climate warming in cold regions.
气候变化，尤其是温度升高，可能通过增强入侵物种的竞争能力，增加它们的入侵和改变生态影响。为了测试变暖对入侵植物的影响，在温室中进行了一个中尺度实验，以研究在模拟变暖条件下，入侵植物伊乐藻和本地湿生植物菹草之间的竞争。这两个物种在两个月内分别在单一种植（无竞争对照）或混合种植（竞争对照）下，在不同温度条件（升温处理或无升温处理）下生长。在菹草中，较高的温度导致根长变短，显著增加了分株的地上特征、总生物量和相对生长率（RGR），但对基株的地上特征没有影响。在温暖条件下，混合种植显著降低了菹草分株的高度，显著降低了分株的根长、分株数量、基株生物量、根冠比和菹草的 RGR。除了根冠比之外，伊乐藻的所有形态、生物量和生长特征都随着温度的升高而显著增加，而在自然温度条件下，混合种植降低了伊乐藻的分株根长、分株数量、基株生物量、根冠比和 RGR。在无升温和升温环境下，伊乐藻的 RCI 和 RII 都比菹草高 2 到 3 倍，而这两个物种的 ACI 值相似。因此，在两种温度条件下，菹草都是比伊乐藻更好的竞争者。这些结果表明，尽管本地物种的优越竞争力可以抑制伊乐藻的生长，但在寒冷地区未来气候变暖的情况下，该物种的表现将会增强。
