Abstract：
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.
摘要：
互花米草的入侵对黄河三角洲滨海湿地生态系统造成了严重破坏,中国。淹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反应差异尚不清楚，目前尚不清楚这些差异如何影响入侵模式。在本文中,分别研究了克隆分株和幼苗。通过文献数据整合分析,实地调查,温室实验,和情景模拟，我们证明了克隆分株和幼苗对洪水和盐度变化的反应存在显着差异。克隆分株没有理论淹没持续时间阈值，盐度阈值为57ppt（千分之几）；幼苗的淹没持续时间阈值约为11小时/天，盐度阈值为43ppt。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，对克隆有显著性意义(P<0.05)。与黄河三角洲的幼苗相比，克隆分株具有更大的潜在可侵蚀性。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反应的限制。在未来海平面上升的情况下，对洪水和盐度的反应差异将导致互花米草进一步压缩本地物种的栖息地。我们的研究结果可以提高互花米草控制的效率和准确性。水文连通性管理和对湿地氮输入的严格限制，例如,是控制互花米草入侵的潜在新举措。
