Open AccessControls on creek margin stability by the root systems of saltmarsh vegetation, Beaulieu Estuary, Southern England
Author(s) -
Yining Chen,
Charlotte Thompson,
Michael B. Collins
Publication year - 2019
Publication title -
anthropocene coasts
Language(s) - English
Resource type - Journals
ISSN - 2561-4150
DOI - 10.1139/anc-2018-0005
Subject(s) - salt marsh , atriplex , root system , erosion , sediment , geology , estuary , juncus , geomorphology , environmental science , hydrology (agriculture) , ecology , botany , biology , oceanography , geotechnical engineering , wetland
The retreat of cliffs (lateral expansion) within tidal creeks results in a net loss of saltmarshes, but this retreat process can be retarded by root systems. To understand the interaction between root presence and bank sediment, quantitative measurements of two saltmarsh species root systems (Atriplex portulacoides and Juncus maritima) were carried out in a saltmarsh in Southern England, and their relationships with bank stability were examined. Computed Tomography (CT) Scanning techniques were used to investigate three-dimensional root architecture. The data obtained (e.g., root volume, diameter, and distribution patterns of roots) were examined alongside more traditional root density measurements. The volumetric percentage, ratio between horizontal (lateral) and vertical roots (H/V ratio), and root diameter distribution are discussed in relation to their influence on bank sediment erosion threshold and shear strength. The results suggest that Atriplex portulacoides is more effective than Juncus maritimus in stabilising banks. This is because root systems that provide a high resistance to flow-induced erosion are better than those that provide a high resistance to gravity-induced erosion in stabilising cliff banks. This conclusion is relevant to future saltmarsh protection and re-establishment.