Silvopastoral system for wood production: opportunities and challenges in tropical and subtropical environments

Tropical and subtropical regions have the largest potential area and climatic conditions for sustainably hosting silvopastoral systems focused on the production of wood and livestock in at least two "production modes". These regions concentrate extensive areas with pastures, in which there is a great opportunity to match forestry production to the profile of regional production rather than competing for land use. This can be beneficial for both productive sectors since certification standards for both forestry and livestock encompass a wide range of economic, social, environmental, and technical management aspects, including people's well-being and livelihoods. It could converge objectives for both businesses toward a central element and disruptive of an innovative bio-based economy. The "wood model" focuses on producing a greater volume of wood biomass. It requires a high tree-stocking rate (33-47%) into pastures. The "cattle model" integrates more pasture production with fewer trees (< 33% tree-stocking rate). This model requires larger spaces between trees to allow for thicker logs (sawn wood). Both models protect herds and forage. In the "wood model", negative interactions occur with still young trees. Spacing between strips generates alleys; alleys need to have a width between 3.5 and 5 times the tree canopy depth. Wide alleys facilitate herding; cattle perceive alleys as open spaces without being spooked by the cowboy approximation. Parallel strips facilitate silvicultural and harvest tree operations, animal herding, uniformity of tree density, minimization of runoff surface, and soil erosion.