DOONIES: A process-based ecogeomorphological functional community model for coastal dune vegetation and landscape dynamics

In ecogeomorphic systems, such as beach-dune habitats, complex couplings exist between geomorphology and ecology. Abiotic conditions influence vegetation growth and distribution while vegetation imposes a geomorphic feedback, impacting topography. Communities affect storm response by impacting pre-storm state, post-storm recovery, and landscape evolution. Despite their importance, beach-dune and other ecogeomorphic land-sea sys-tems are deteriorating with increased anthropogenic modification and amplified natural disaster impact linked to climate change. A structured approach is needed to develop a more comprehensive understanding of coastal vegetation community interactions with the environment as these interactions underpin topographic change, strom response, and restoration and management efforts. Toward this goal, a spatially explicit process-based grid model, the DOONIES Model, encompassing biological, physiological, and geomorphological drivers of land-scape change is presented. DOONIES simulates critical biotic and abiotic processes of vegetation growth, abun-dance, and spatial distribution dynamics impacting topography and storm response. Biological processes and ecogeomorphic responses are tailored to generalizable dune functional-communities with species-specific repre-sentatives. Estimates of the balance between photosynthesis and respiration dictate plant growth and morphol-ogy spatiotemporally which in turn impact sediment erosion and deposition. Relative sensitivity analyses indicate that the model is fundamentally driven by the photosynthesis formulation, where parameters such as maximum daily photosynthesis (grams of carbohydrate per day) and light intensity impact vegetation growth. These in turn, indirectly impact topographic change in modeled ecogeomorphic links. DOONIES is standalone and with a biological focus making it unique compared to more physical morphodynamic and hydrodynamic models with which this model is designed to couple. The model was evaluated by comparing simulation topog-raphy to actual across 6 years at Island Beach State Park, NJ while modeling Hurricane Sandy and daily wind con-ditions driving sediment input and output events. The predicted results were within the measurement error for the elevation datasets that the simulations were based on. This new model affords dynamic predictions of the re-sponse of naturally occurring and planted dune vegetation communities to typical abiotic conditions, as a tool for supporting and exploring restoration decisions.Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons. org/licenses/by-nc-nd/4.0/).

Automated summary

In ecogeomorphic systems, there are complex couplings between geomorphology and ecology, where abiotic conditions influence vegetation growth and distribution, and the feedback from vegetation impacts topography. Communities play a role in storm response and landscape evolution. However, these systems, such as beach-dune habitats, are deteriorating due to anthropogenic modification and climate change. In order to develop a better understanding of the interactions between coastal vegetation communities and the environment, a structured approach is needed. The DOONIES Model, a spatially explicit process-based grid model, is presented to simulate the biological, physiological, and geomorphological drivers of landscape change in beach-dune habitats. The model focuses on vegetation growth, abundance, and spatial distribution dynamics, and it can be used to support restoration decisions.