Spatial and temporal patterns of initial plant establishment in salt marsh communities

Lõhmus, K., Balke, T. and Kleyer, M. (2020) Spatial and temporal patterns of initial plant establishment in salt marsh communities. Journal of Vegetation Science, 31(6), pp. 1122-1132. (doi: 10.1111/jvs.12915)

Abstract

Questions: How are dispersal processes, abiotic and biotic interactions determining the initial salt marsh plant community establishment and development when connectivity is different? We aim to answer this question by analysing the spatial and temporal patterns of plant establishment along the environmental gradient at two connectivity settings. Location: Back‐barrier salt marsh and tidal flats of Spiekeroog, northwest Germany Methods: We established an experiment along the salt marsh elevation gradient with bare sediment open for spontaneous colonisation on the natural salt marsh and on the experimental salt marsh islands built on the tidal flats approximately 500 m from the natural salt marsh for low connectivity. Plant establishment was identified from georeferenced photos at least monthly. Results: Experimental islands as low connectivity plots had limited colonisation by annual halophytes that produce large number of small seeds. Number of individuals increased with higher connectivity at salt marsh enclosed patches. Number of individuals was highest at the mid elevations whereas peak species richness was at the upper salt marsh. Temporal patterns of seedling emergence showed increasing plant numbers until end of April followed by gradual incline over the season at the pioneer and lower salt marsh zones. Upper elevations on the other hand had a stable number of low individual counts over time. Spatial clustering of plant individuals indicating possible facilitation was important at the initial stages of salt marsh development at pioneer and lower salt marsh elevation, but only early in the season. Conclusions: Stochastic patterns of early salt marsh colonisation indicated that success of species colonisation was determined by seed properties, seed availability and environmental conditions mediated by elevation. We found indications, that further colonisation was supported by already colonised plants at initial stages, but shifted to avoidance later in the season.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Balke, Dr Thorsten
• Authors: Lõhmus, K., Balke, T., and Kleyer, M.
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences
• Journal Name: Journal of Vegetation Science
• Publisher: Wiley
• ISSN: 1100-9233
• ISSN (Online): 1654-1103
• Published Online: 19 June 2020
• Copyright Holders: Copyright © 2020 The Authors
• First Published: First published in Journal of Vegetation Science 31(6): 1122-1132
• Publisher Policy: Reproduced under a Creative Commons License