The model version DART-BIO has been developed especially for analyzing global land use change and biofuel policies. The version depicts the special features of a disaggregated agricultural sector. Primary agricultural goods are produced with capital, labor, intermediate inputs, and land. In DART-BIO we use the GTAP-AEZ database containing 18 AEZs which are characterized by six different lengths of growing periods spread over three different climatic zones. By incorporating AEZs, the model accounts for land heterogeneity in terms of crop suitability, productivity potential and environmental impact.
Another feature of DART- BIO is a detailed representation of the agricultural sector and biofuel industries. As explained in Calzadilla et al. (2016), some sectors are not explicitly included in the original GTAP database (such as maize and biodiesel) and are therefore carved out from embedded sectors. Thus, new sectors/ products are added to the standard GTAP database, so that DART-BIO includes in total 38 sectors and 45 products. In addition, DART-BIO explicitly accounts for the by-products generated during the production of different vegetable oils and bioethanol. Those by-products are used as fodder in livestock production and their inclusion in DART-BIO allows analyzing feedbacks between livestock and biofuel industries (Caldazilla et al. 2016).
Production is incorporated via the respective nesting structures expressed by a CES production function. DART-BIOthus captures the complex value chains in agriculture by simultaneously accounting for sectoral linkages, the heterogeneity of land and different uses of land. Furthermore, by aggregating the model into 23 regions and 38 sectors, regional changes can be evaluated. Recent publications using DART-BIO include Mauser et al. (2015), and Delzeit et al. (2016), Delzeit et al. (2017), Delzeit et al. (2018). Currently, it is used in the BIONEX project. In Calzadilla et al. (2016) further information on DART-BIO can be found.