Mechanistic Biogeochemical Model Applications for Everglades Restoration: A Review of Case Studies and Suggestions for Future Modeling Needs

Abstract

Mechanistic biogeochemical model applications for freshwater wetland ecosystems are reviewed with an emphasis on applications in the Florida Everglades. Two significant human impacts on the Everglades have been hydrologic alteration and phosphorus (P) enrichment. Thus, it is important for research conducted in support of Everglades restoration to integrate understanding of the coupled effects of hydrologic and biogeochemical processes. Models are tools that can facilitate such integration, but an important challenge in model development is determining the appropriate level of model complexity. Previous wetland biogeochemical and flow modeling efforts are categorized across the spectrum of complexity from empirical and spatially aggregated to mechanistic and spatially distributed. The focus of this review is on mercury and P, as these two elements represent major environmental concerns in this ecosystem. Two case studies of coupled hydrologic and biogeochemical modeling for P transport are described in further detail to illustrate the implications of different levels of model complexity. The case study simulation results on time series TP data revealed that the mechanistic biogeochemical model with more complexity did not guarantee significantly better simulation accuracy compared to the simpler one. It is concluded that the level of model complexity should be represented appropriately based on the modeling objectives, hypotheses to be tested, and data availability. Finally, better integration between data collection and model development is encouraged as cross-fertilization between these processes may stimulate improved system understanding.

KEYWORDS:

• biogeochemical model
• Everglades
• mechanistic model
• phosphorus cycling
• restoration
• wetland