Can cheniers protect mangroves along eroding coastlines? – The effect of contrasting foreshore types on mangrove stability

Celine E.J. van Bijsterveldt*, Daphne van der Wal, Alejandra Gijón Mancheño, Gregory S. Fivash, Muhammad Helmi, Tjeerd J. Bouma

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

4 Citations (Scopus)
48 Downloads (Pure)

Abstract

Mangrove forests are increasingly valued as wave-attenuating buffers in coastal flood defence strategies. However, as mangroves are vulnerable to wave-induced erosion, this raises the question, how can the stability of these protective mangrove forests be promoted? To address this question, we investigate how mangrove dynamics in a microtidal system can be related to different types of foreshores. We used remote sensing to investigate mangrove fringe stability over multiple years in relation to intertidal mudflat width (i.e., emerged at low tide) and the presence stability of cheniers, which are sand bodies on top of muddy foreshores that are characteristic for eroding coastlines. In addition, we investigated local and short-term foreshore effects by measuring wave propagation across two cross-shore transects, one with a mudflat and chenier and one with a deeper tidal flat foreshore. The satellite images (Sentinel-2) revealed that mangrove dynamics over multiple years and seasons were related to chenier presence and stability. Without a chenier, a mudflat width of 110 m (95%CI: 76–183 m) was required to make mangrove expansion more likely than mangrove retreat. When a stable chenier was present offshore for two years or more, a mudflat width of only 16 m (95%CI: 0–43 m) was enough to flip chances in favor of mangrove expansion. However, mangrove expansion remained heavily influenced by seasonal changes, and was highly event driven, succeeding only once in several years. Finally, although mudflat width was a direct driver of mangrove expansion, and could be targeted as such in coastal management, our field measurements demonstrated that cheniers also have an indirect effect on mangrove expansion. These sand banks significantly reduce wave height offshore, thereby likely creating favorable conditions for mudflat accretion landward, and thus mangrove habitat expansion. This makes stabilization - and possibly also the temporary creation - of cheniers an interesting target for mangrove conservation and restoration.

Original languageEnglish
Article number106863
JournalEcological Engineering
Volume187
DOIs
Publication statusPublished - 2023

Keywords

  • Cheniers
  • Foreshore
  • Mangrove dynamics
  • Mudflats
  • Wave reduction

Fingerprint

Dive into the research topics of 'Can cheniers protect mangroves along eroding coastlines? – The effect of contrasting foreshore types on mangrove stability'. Together they form a unique fingerprint.

Cite this