COS 137-2 - Cattle pastures as carbon sinks: an analysis of tree carbon, beef production, and woody species diversity in temperate and tropical pasturelands
Abstract: Forest restoration is the most effective natural climate solution, with the potential to sequester 37% of the carbon dioxide (CO2) needed to reach the Paris climate mitigation goal. Cattle pastures offer an underutilized opportunity to increase global restoration efforts, improve biodiversity, and maximize carbon storage through the adoption of management strategies that prioritize the incorporation of trees into pasturelands. Yet, the effect of increased trees on cattle production is not well-documented across biomes. Furthermore, the restoration potential of these landscapes as a byproduct of tree carbon remains to be studied. Therefore, the aims of this study were (i) evaluate the effect of increasing tree carbon (MgC/ha) on the pastoral stocking density (AU/ha), (ii) quantify the woody species diversity (H’) within pastures, and (iii) compare findings between farms in temperate (n = 26) and tropical (n = 16) ecosystems. The pastoral carbon storage in temperate forest ecosystems of Virginia, USA and dry tropical forest ecosystems of Los Santos, Panama was estimated remotely and verified with in-situ plots. Woody plant species were also quantified to determine diversity as a metric of ecological restoration potential within these systems. There was no difference in MgC/ha between tropical farms and temperate farms, but H’ (p < 0.001) and stocking density (AU/ha) were significantly higher in Los Santos, Panama (p = 0.003). Additionally, farms enrolled in conservation programs had lower stocking densities than those that practiced traditional management (p = 0.026), but no significant differences in H’ or MgC/ha. There was also no effect of MgC/ha on stocking density, which suggests that pastures with more trees did not result in a decrease in beef production. Woody species diversity (H’) was positively associated with increasing MgC/ha (p < 0.001), in Los Santos, but not in Virginia. These findings demonstrate the potential for pastures to increase above ground tree carbon and potentially woody species diversity without decreasing beef production. Moreover, such efforts support landscape restoration and offer potentially novel revenue streams for farmers through carbon credit programs.
