Chao Chuanxin, Chen Xiaorong, Wang Jie, Xie Yonghong
Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China.
Technology Innovation Center for Ecological Conservation and Restoration in Dongting Lake Basin, Ministry of Natural Resources, Changsha, China.
Front Plant Sci. 2024 Sep 3;15:1450404. doi: 10.3389/fpls.2024.1450404. eCollection 2024.
Climate change and intensified human activities have disrupted the natural hydrological regime and rhythm of river-connected lakes, extending the dry season, increasing water loss, and exposing previously submerged lake floors. This exposure has led to significant sediment hardening, which directly impacts submerged macrophytes. However, strategies to mitigate the negative effects of hardened sediments and promote the growth and development of submerged macrophytes remain largely unexplored. In this study, we selected typical hardened sediment from Dongting Lake to investigate the response of different growth forms of submerged macrophytes to multiple sediment remediation measures (loosening and litter addition) using a mesocosm experiment. The results indicated that loosening alone uniformly benefited all submerged macrophytes by increasing total biomass, relative growth rate (RGR), and the root/shoot ratio. Additionally, loosening altered the root traits of submerged macrophytes, promoting maximum root length (MRL) while reducing average root diameter (ARD). Moreover, different submerged macrophytes exhibited species-specific responses to the combination of loosening and litter addition. Notably, the combination of loosening and adding litter had an antagonistic effect on the growth of and . The response of functional traits of submerged macrophytes with similar growth forms to the same treatment was consistent. Our findings suggest that future sediment remediation efforts should consider matching specific treatments with the growth forms of submerged macrophytes to achieve optimal outcomes.
气候变化和人类活动加剧扰乱了与河流相连湖泊的自然水文状况和节律，延长了旱季，增加了水分流失，并使先前被淹没的湖底暴露出来。这种暴露导致了显著的沉积物硬化，直接影响了沉水植物。然而，减轻硬化沉积物负面影响并促进沉水植物生长发育的策略在很大程度上仍未得到探索。在本研究中，我们从洞庭湖选取典型的硬化沉积物，通过中宇宙实验研究了多种沉积物修复措施（疏松和添加凋落物）对不同生长形式沉水植物的响应。结果表明，单独疏松通过增加总生物量、相对生长速率（RGR）和根冠比，对所有沉水植物均有一致的益处。此外，疏松改变了沉水植物的根系性状，促进了最大根长（MRL），同时减小了平均根直径（ARD）。而且，不同的沉水植物对疏松和添加凋落物的组合表现出物种特异性反应。值得注意的是，疏松和添加凋落物的组合对[具体植物1]和[具体植物2]的生长具有拮抗作用。具有相似生长形式的沉水植物功能性状对相同处理的响应是一致的。我们的研究结果表明，未来的沉积物修复工作应考虑将特定处理与沉水植物的生长形式相匹配，以实现最佳效果。
