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Coupled topographic and vegetation patterns in coastal dunes: Remote sensing observations and ecomorphodynamic implications
Author(s) -
Yousefi Lalimi F.,
Silvestri S.,
Moore L. J.,
Marani M.
Publication year - 2017
Publication title -
journal of geophysical research: biogeosciences
Language(s) - English
Resource type - Journals
eISSN - 2169-8961
pISSN - 2169-8953
DOI - 10.1002/2016jg003540
Subject(s) - foredune , ecotone , vegetation (pathology) , lidar , geology , biomass (ecology) , remote sensing , physical geography , environmental science , aeolian processes , geomorphology , hydrology (agriculture) , geography , ecology , oceanography , habitat , medicine , pathology , geotechnical engineering , biology
Vegetation plays a key role in stabilizing coastal dunes and barrier islands by mediating sand transport, deposition, and erosion. Dune topography, in turn, affects vegetation growth, by determining local environmental conditions. However, our understanding of vegetation and dune topography as coupled and spatially extensive dynamical systems is limited. Here we develop and use remote sensing analyses to quantitatively characterize coastal dune ecotopographic patterns by simultaneously identifying the spatial distribution of topographic elevation and vegetation biomass. Lidar‐derived leaf area index and hyperspectral‐derived normalized difference vegetation index patterns yield vegetation distributions at the whole‐system scale which are in agreement with each other and with field observations. Lidar‐derived concurrent quantifications of biomass and topography show that plants more favorably develop on the landward side of the foredune crest and that the foredune crestline marks the position of an ecotone, which is interpreted as the result of a sheltering effect sharply changing local environmental conditions. We conclude that the position of the foredune crestline is a chief ecomorphodynamic feature resulting from the two‐way interaction between vegetation and topography.