Tidal channel-mediated gradients facilitate Spartina alterniflora invasion in coastal ecosystems: implications for invasive species management
Tidal channel-mediated gradients facilitate Spartina alterniflora invasion in coastal ecosystems: implications for invasive species management
复制标题
潮汐通道介导的梯度促进互花米草入侵沿海生态系统：对入侵物种管理的影响
DOI：
10.3354/meps13560
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发表时间：
2020
影响因子：
2.5
通讯作者：
T. J. Bouma
中科院分区：
文献类型：
--
作者：
Ning Z. H.;C. Chen;Z. C. Zhu;T. Xie;Q. Wang;B. S. Cui;T. J. Bouma
了解地貌景观特征如何影响自然栖息地条件，对于预测这些地貌景观特征是否可能成为促进入侵物种在沿海生态系统中扩张的通道至关重要。虽然各种非生物和生物因素对盐沼植物入侵的影响已经得到了很好的研究，但潮汐通道对植物入侵的影响却知之甚少。本文研究了黄河三角洲不同海拔湿地（低、中、高）潮汐通道边缘互花米草横向扩张的自下而上影响因素。野外观测和试验结果表明，潮道边缘微生境土壤盐度较低，淹没程度较高，有利于互花草的建立、生长、定殖和有性繁殖。此外，潮道边缘对植物向陆地入侵的促进作用在中、高沼泽区比低沼泽区更为敏感。高繁殖体压力加上潮道内形成的结构性微生境的适宜物理条件，可能促进了互花草沿潮道边缘的快速扩张。在此基础上，建立了潮汐通道介导入侵植物横向扩张机制的概念模型。这些结果强调了潮汐通道介导的梯度在自下而上的非生物和生物扩散因子中促进沿海入侵植物扩张的重要性。对于湿地管理，应将地貌景观特征纳入生态管理和入侵植物风险评估。
Understanding how geomorphic landscape features affect physical habitat conditions is essential for predicting if such geomorphic landscape features may act as conduits facilitating invasive species expansion in coastal ecosystems. Although the effects of various abiotic and biotic factors on plant invasion in salt marshes have been well studied, little is known about the impact of tidal channels on plant invasion. Here, we examined the effects of bottom-up determinants on the lateral expansion of Spartina alterniflora in tidal channel margins of different elevational marsh zones: the low, middle and high marsh, in the Yellow River Delta, China. Field observations and experiments showed that the microhabitats of tidal channel margins are characterized by relatively low soil salinity and high inundation, which significantly facilitated the establishment, growth, colonization and sexual reproduction of S. alterniflora. Moreover, the facilitating effect of tidal channel margins on plant landward invasion appeared more sensitive in middle and high marshes compared with the low marshes. High propagule pressure combined with suitable physical conditions of the structural microhabitats formed within tidal channels potentially promoted the rapid expansion of S. alterniflora along the tidal channel margins. Based on these results, a conceptual model was built illustrating the lateral expansion mechanisms of the invasive plant mediated by tidal channels. These results highlight the importance of tidal channel-mediated gradients in bottom-up abiotic and biotic-dispersal factors in facilitating the expansion of coastal invasive plants. For wetlands management, our results imply that geomorphic landscape features should be incorporated into ecological management and risk assessment of invasive plants.