A model for estimating windbreak carbon within COMET-Farm

Agroforestry as a land management practice presents a method for partially offsetting greenhouse gas emissions from agricultural land. Of all agroforestry practices in the United States, windbreaks in particular are used throughout the United States providing a useful starting point for deriving a modelling system which could quantify the amount of carbon sequestered on U.S. agricultural land and provide for broad usability. We present our first approximation to this end by presenting a model that estimates current and future stocks within multiple carbon pools of windbreak systems such as live trees, the O horizon, downed woody debris and standing dead trees. In this article, we describe each modelled process driving carbon fluxes within carbon pools including novel windbreak tree growth and mortality models. Our model is generalized by region and species group allowing us to run scenarios for any common tree species in any location within the contiguous United States. Integrated into the agricultural greenhouse gas accounting tool, COMET-Farm™, the windbreak component gives landowners and land managers power to view agroforestry systems in the same context as agricultural operations and provides an alternative to intensive biomass inventories.