Simulating Regional Vegetation‐climate Dynamics for Middle America: Tropical Versus Temperate Applications

Regional vegetation‐climate modelling studies have typically focused on boreal or temperate ecosystems in North America and Europe, almost completely overlooking tropical ecosystems. We present the first results of simulated regional vegetation‐climate dynamics in Middle America as simulated by the model, LPJ‐GUESS. The Kappa statistic indicated poor agreement, with a Kappa value of 0.301. When we modified the Kappa statistic by aggregating cell sizes and using generalized biomes, the Kappa value increased to 0.543, indicating a fair agreement. Total LAI simulated from LPJ‐GUESS was strongly correlated to remotely sensed LAI values (r = 0.75). Our simulations indicate that fire frequency was overestimated in tropical moist forests and underestimated in savannas. This underestimation of fire resulted in an over‐simulation of dry tropical forest at the expense of savanna. We highlight additional reasons for the initially poor representation of vegetation in Middle America, including factors such as non‐parameterized plant functional types (desert shrub, cacti, and other succulents), rugged topography, and an insufficient representation of soil.