2020 ESA Annual Meeting (August 3 - 6)

LB 19 Abstract - A model comparison of how fire return intervals impact carbon and species dynamics in a southeastern U.S. pineland

Steve Flanagan, Wildland Fire Science, Tall Timbers Research Station and Land Conservancy, Tallahassee, FL, E. Louise Loudermilk, Southern Research Station, Center for Forest Disturbance Science, USDA Forest Service, Athens, GA, J. Kevin Hiers, Fire Research, Tall Timbers Research Station, Tallahassee, FL and Mac A. Callaham Jr., Southern Research Station, USDA Forest Service, Athens, GA
Background/Question/Methods

Ecosystem models predict how forests respond to disturbances at a range of scales. Selection of the class of model used should depend on the scale of the research question, and model type on the desired ecosystem attributes of interest. Cases exist where multiple classes of model could be used to address a research question, each scale with potential benefits and drawbacks. This study illustrated the similarities and differences between two classes of models in relation to how fire return intervals impact carbon and species dynamics in a southeastern U.S. pineland. A global class (ED) and landscape class (LANDIS-II) model were parameterized with data provided by The Jones Center at Ichauway, calibrated with literature values, and validated with eddi-covariance flux tower data also from the The Jones Center. Scenarios that represented prescribed fire (2 yr frequency), fire exclusion, and three wildfire scenarios (20, 50, 100 yr frequency), were then run to compare and contrast ecosystem carbon and species response.

Results/Conclusions

ED illustrated that prescribed fire provided the greatest carbon benefit and most stable above ground biomass and species through time, which LANDIS-II also found except for when fire exclusion occurred on the order of centuries, which is unlikely in this fire prone landscape. Differences, which were found in the wildfire scenarios, were primarily the result of the inherent differences in heterogeneity associated with each class of model. The benefits and drawbacks of each approach is highlighted. This study, at multiple scales, supports an aggressive prescribed fire regime in southeastern U.S. pinelands for carbon and species benefits, which would also aid the prevention of biodiversity loss and preservation of endemic species in an ecosystem that is a hotspot of diversity.