School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China; Yellow River Estuary Wetland Ecosystem Observation and Research Station, Ministry of Education, Shandong 257500, China.
School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China; Research and Development Center for Watershed Environmental Eco-Engineering, Advanced Institute of Natural Science, Beijing Normal University at Zhuhai, Guangdong 519087, China.
Sci Total Environ. 2023 Jun 15;877:162803. doi: 10.1016/j.scitotenv.2023.162803. Epub 2023 Mar 11.
The invasion of Spartina alterniflora has caused severe damage to the coastal wetland ecosystem of the Yellow River Delta, China. Flooding and salinity are key factors influencing the growth and reproduction of S. alterniflora. However, the differences in response of S. alterniflora seedlings and clonal ramets to these factors remain unclear, and it is not known how these differences affect invasion patterns. In this paper, clonal ramets and seedlings were studied separately. Through literature data integration analysis, field investigation, greenhouse experiments, and situational simulation, we demonstrated significant differences in the responses of clonal ramets and seedlings to flooding and salinity changes. Clonal ramets have no theoretical inundation duration threshold with a salinity threshold of 57 ppt (part per thousand); Seedlings have an inundation duration threshold of about 11 h/day and a salinity threshold of 43 ppt. The sensitivity of belowground indicators of two propagules-types to flooding and salinity changes was stronger than that of aboveground indicators, and it is significant for clones (P < 0.05). Clonal ramets have a larger potentially invadable area than seedlings in the Yellow River Delta. However, the actual invasion area of S. alterniflora is often limited by the responses of seedlings to flooding and salinity. In a future sea-level rise scenario, the difference in responses to flooding and salinity will cause S. alterniflora to further compress native species habitats. Our research findings can improve the efficiency and accuracy of S. alterniflora control. Management of hydrological connectivity and strict restrictions on nitrogen input to wetlands, for example, are potential new initiatives to control S. alterniflora invasion.
互花米草的入侵对中国黄河三角洲滨海湿地生态系统造成了严重破坏。洪水和盐度是影响互花米草生长和繁殖的关键因素。然而，互花米草幼苗和克隆分株对这些因素的响应差异尚不清楚，也不知道这些差异如何影响入侵模式。本研究分别对克隆分株和幼苗进行了研究。通过文献数据综合分析、野外调查、温室实验和现场模拟，我们证明了克隆分株和幼苗对洪水和盐度变化的响应存在显著差异。克隆分株没有理论上的淹没持续时间阈值，但有 57 ppt（每千分比）的盐度阈值；幼苗的淹没持续时间阈值约为 11 小时/天，盐度阈值为 43 ppt。两种繁殖体类型的地下指标对洪水和盐度变化的敏感性强于地上指标，对克隆体而言差异显著（P<0.05）。与幼苗相比，互花米草克隆分株在黄河三角洲具有更大的潜在可入侵面积。然而，互花米草的实际入侵面积通常受到幼苗对洪水和盐度的响应限制。在未来海平面上升的情景下，对洪水和盐度的响应差异将导致互花米草进一步压缩本地物种的栖息地。本研究结果可以提高互花米草控制的效率和准确性。例如，管理水文连通性和严格限制湿地氮输入等措施，可能是控制互花米草入侵的新举措。
