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Title: Tidal channel meanders serve as stepping‐stones to facilitate cordgrass landward spread by creating invasion windows
Abstract

Understanding the mechanisms by which the geomorphic structures affect habitat invasibility by mediating various abiotic and biotic factors is essential for predicting whether these geomorphic structures may provide spatial windows of opportunity to facilitate range‐expansion of invasive species in salt marshes. Many studies have linked geomorphic landscape features such as tidal channels to invasion by exotic plants, but the role of tidal channel meanders (i.e., convex and concave sides) in regulating theSpartina alterniflorainvasion remains unclear. Here, we examined the combined effects of tidal channel meander‐mediated hydrodynamic variables, soil abiotic stresses, and propagule pressure on the colonization ofSpartinain the Yellow River Delta, China, by conducting field observations and experiments. The results showed that lower hydrodynamic disturbance, bed shear stress, and higher propagule pressure triggered by eddies due to the convex structure of channel meanders facilitatedSpartinaseedling establishment and growth, whereas the concave side considerably inhibited theSpartinainvasion. Lower soil abiotic stresses also significantly promoted the invasibility of the channel meanders bySpartina. Based on these findings, we propose a conceptual framework to illustrate the effects of the meandering geomorphology of tidal channels on the mechanisms that might allow the landward spread ofSpartinaand related processes. Our results demonstrate that the meandering geomorphic structures of tidal channels could act as stepping‐stones to significantly facilitate the landward invasion ofSpartinaalong tidal channels. This implies that geomorphic characteristics of tidal channels should be integrated into invasive species control and salt marsh management strategies.

 
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NSF-PAR ID:
10484698
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Ecological Applications
Volume:
34
Issue:
1
ISSN:
1051-0761
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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