Incorporating plant-species variation in biogenic emission rates into regional weather and climate models

We introduce a method to incorporate vegetation-species-based variation of the emission of biogenic volatile organic compounds (BVOCs) into regional weather and climate models. We convert a species-based land-cover database for Texas into a database compatible with the Noah land-surface model (LSM) and into a database compatible with the Community Land Model (CLM). We link the LSM-compatible land-cover databases to the original species-based dataset as a means to derive region-specific BVOC emission capacities for each land cover type (in the Noah database) and for each plant functional type (in the CLM database).

The inherent BVOC flux rates (defined as the product of the BVOC emission capacity and the leaf biomass density) derived using the Texas-specific BVOC emissions capacities are well correlated with the inherent BVOC flux rates calculated using the original species data (r = 0.89). The mean absolute error for the emission-capacity–derived inherent flux rates is an order of magnitude lower than the range of inherent flux rates.

The ground-referenced land-cover databases derived here are likely more accurate than their satellite-derived counterparts; they can be used for a variety of regional weather and climate simulations in Texas. Inherent BVOC flux rates derived using region-specific BVOC emission capacities are more consistent with observations than are those derived using globally constant BVOC emission capacities. When used in conjunction with detailed land-cover datasets, region-specific BVOC emission capacities produce reasonably accurate inherent BVOC flux rates.