Mechanistic Fire Disturbance and Ecosystem Response Model: Cycled fire disturbances in longleaf pine ecosystems
Abstract
Approximately half of the world's ecoregions are fire-dependent, all of which provide multiple ecosystem services including critical habitat for threatened and endangered species. One such fire-dependent ecosystem is the longleaf pine ecosystem where successive prescribed fire intervals are used to manage ecosystem structure and function. However, the consequences of how these ecosystems will interact with shifts in both managed and unmanaged fire behavior as a result of climate change is not known. Given that climate change will drive the system outside of the observed conditions, current modeling techniques based on those observations are poorly suited to capture fire-dependent ecosystem trajectory over multiple fire disturbances. Here mechanistic modeling based on the underlying physics of fire behavior and ecohydrologic response offers a possible path to understanding fire-dependent ecosystem trajectory in a climate perturbed condition. We demonstrate a proof of concept disturbance and response model (DRM) that incorporates a physics-based approach to simulating fire behavior, hydrologic conditions, and ecosystem response. The DRM is built from a fully coupled surface and subsurface hydrologic model (ParFlow) that provides fuel moisture conditions to a fire behavior model (FIRETEC) that resolves fire-atmosphere interactions. The fire disturbance simulated by FIRETEC then produces a fire disturbance footprint onto a longleaf pine ecosystem growth model (LLM) that simulates the growth of fire-dependent species. In turn, the LLM is used to both evaluate habitat suitability of species of concern as well as set-up the fuel loads for the succeeding fire disturbances. This cycled fire disturbance and response model then provides a metric to assess ecosystem condition as it evolves from successive fire disturbance. We can further demonstrate how changing fire behavior in response to unique fuel moisture profiles create different disturbance regimes, and further how those differing disturbance regimes produce altered ecosystem structure.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.B41A..07A
- Keywords:
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- 0428 Carbon cycling;
- BIOGEOSCIENCES;
- 0486 Soils/pedology;
- BIOGEOSCIENCES;
- 0496 Water quality;
- BIOGEOSCIENCES;
- 1807 Climate impacts;
- HYDROLOGY