Wang Mo-Zhu, Liu Zheng-Yuan, Luo Fang-Li, Lei Guang-Chun, Li Hong-Li
School of Nature Conservation, Beijing Forestry University, Beijing, China.
PLoS One. 2016 Jan 6;11(1):e0146528. doi: 10.1371/journal.pone.0146528. eCollection 2016.
Submerged macrophytes are subjected to potential mechanical stresses associated with fluctuating water levels in natural conditions. However, few experimental studies have been conducted to further understand the effects of water level fluctuating amplitude on submerged macrophyte species and their assemblages or communities. We designed a controlled experiment to investigate the responses of three submerged macrophyte species (Hydrilla verticillata, Ceratophyllum demersum and Elodea nuttallii) and their combinations in communities to three amplitudes (static, ± 30 cm, ± 60 cm) of water level fluctuations. Results showed that water level fluctuating amplitude had little effects on the community performance and the three tested species responded differently. H. verticillata exhibited more growth in static water and it was negatively affected by either of the water level fluctuations amplitude, however, growth parameters of H. verticillata in two fluctuating water level treatments (i.e., ± 30 cm, ± 60 cm) were not significantly different. On the other hand, the growth of C. demersum was not significantly correlated with different amplitude treatments. However, it became more abundant when water levels fluctuated. E. nuttallii was inhibited by the two fluctuating water level treatments, and was less in growth parameters compared to the other species especially in water level fluctuating conditions. The inherent differences in the adaptive capabilities of the tested species indicate that C. demersum or other species with similar responses may be dominant species to restore submerged macrophyte communities with great fluctuating water levels. Otherwise, H. verticillata, E. nuttallii or other species with similar responses could be considered for constructing the community in static water conditions.
在自然条件下，沉水植物会受到与水位波动相关的潜在机械应力影响。然而，很少有实验研究来进一步了解水位波动幅度对沉水植物物种及其组合或群落的影响。我们设计了一项对照实验，以研究三种沉水植物物种（黑藻、金鱼藻和伊乐藻）及其群落组合对三种水位波动幅度（静态、±30厘米、±60厘米）的响应。结果表明，水位波动幅度对群落表现影响较小，且三种受试物种的反应各不相同。黑藻在静水中生长得更好，任何一种水位波动幅度都会对其产生负面影响，不过，黑藻在两种波动水位处理（即±30厘米、±60厘米）下的生长参数并无显著差异。另一方面，金鱼藻的生长与不同幅度处理并无显著相关性。然而，当水位波动时，它变得更加繁茂。伊乐藻受到两种波动水位处理的抑制，与其他物种相比，其生长参数较低，尤其是在水位波动条件下。受试物种适应能力的内在差异表明，金鱼藻或其他具有类似反应的物种可能是恢复水位波动较大的沉水植物群落的优势物种。否则，黑藻、伊乐藻或其他具有类似反应的物种可考虑用于构建静水条件下的群落。
