Monitoring considerations for a dynamic dune restoration project: Pacific Rim National Park Reserve, British Columbia, Canada.

Abstract

Historically, management of coastal dune systems has often involved artificial stabilization of active sand surfaces in order for coastal areas to be more easily controlled and modified for human benefit. In North America, the introduction of invasive grasses, namely European and American beach (marram) grasses (Ammophila spp.) has been one of the most successful strategies used for stabilizing active coastal dune sands. Recent research has demonstrated, however, that stabilization of coastal dunes often leads to reduced landform complexity and resilience, as well as declines in species diversity. More ‘dynamic’ restoration efforts have emerged over the past 20 years that encourage dune mobility and aeolian activity in order to provide a more resilient biogeomorphic system. In North America, there is generally little research relating restoration methods and outcomes to geomorphic responses despite the fundamental importance of sedimentary processes and dune morphodynamics in broader ecosystem function. This paper aims to better situate dynamic dune restoration within current geomorphic understanding. A brief review of key terms and concepts used in the emerging field of dynamic dune restoration is provided and expanded upon with respect to geomorphologic considerations. A case study of a recent dynamic restoration effort in Pacific Rim National Park Reserve, British Columbia, Canada is provide to demonstrate how these concepts are applied. Introduction of European marram at this site, coupled with a warming climate and increased precipitation in recent decades at this site, is thought to be associated with a rapid decline in aeolian activity, system stabilization and accelerated ecological succession. Preliminary results on the response of the dune system to mechanical removal of Ammophila are presented to provide the foundation for a research framework to guide the broader restoration project. Recommendations for improving treatment methodologies and monitoring protocols are provided to aid future restoration projects of this nature. Copyright © 2013 John Wiley & Sons, Ltd.

Beach–dune sediment budgets and dune morphodynamics following coastal dune restoration, Wickaninnish Dunes, Canada

“…Repeat surveys used to estimate sediment budgets include a temporal dimension that extends interpretation into a fuller spatial-temporal (four-dimensional, 4D) domain, thereby improving our ability to more effectively detect morphodynamic changes related to sediment budget responses (James et al, 2012). Details of the restoration objectives, rationale and methods are outlined in Darke et al (2013) which reviewed preliminary data, guiding the current study and informing the ongoing restoration project. This paper presents results from three years of geomorphic monitoring and sediment budget (volumetric change) analysis following removal of invasive Ammophila spp.…”

Geomorphic and sediment volume responses of a coastal dune complex following invasive vegetation removal

“…Rationale and key goals of the broader restoration project are discussed in Darke et al . () and include enhancing sediment exchanges and morphodynamics within and between the foredune and transgressive dune system. A geostatistical approach using Kriging was used to model statistically significant changes within discrete, linked geomorphic units (beach, foredune, and transgressive dune), which captures and incorporates inherent spatial structure in measured elevation datasets at the sub‐landscape scale as controlled by distinctly different process‐response dynamics.…”

“…Discussion of broader rationale for the restoration project as well as responses at other locations within the Wickaninnish Dunes complex are provided in Darke et al . ().…”

“…A stretch of approximately 3 km of foredune was identified by PCA in 2009 for restoration and, during the first phase of the project on September 21, 2009, PCA removed Ammophila from approximately 200 m of foredune at several sites that straddled pre-existing, cross-shore coastal erosion monitoring profiles (Walker and Beaugrand, 2008;Darke et al, 2013) (Figure 3). Profiles extend from the forest margin at the back of the transgressive dune complex, over the foredune and down the beach into the intertidal zone.…”

A tribute to the influence of Dr Robin Davidson‐Arnott in coastal and aeolian geomorphology

“…Davidson‐Arnott, ). In this special issue, several of the contributed papers describe the annual to decadal morphodynamics of the foredune at Greenwich Dunes, PEI (Ollerhead et al ., ), controls on transgressive dunefields in southern Brazil (Miot da Silva and Hesp, ), the application of remote sensing techniques to examine beach–dune interaction (Delgado‐Fernandez et al ., 2009), beach–dune interaction at St Joseph Spit in northwest Florida (Bitton and Hesp, 2013), climatic influences on dune scarping (Heathfield et al ., ), and foredune restoration (Darke et al ., ; Eamer et al ., ).…”