Carbon stocks and tree diversity in scattered tree silvopastoral systems in Chiapas, Mexico

Carbon sequestration in livestock systems through silvopastoral practices can help reduce the net greenhouse gas emissions. In this study, we evaluated the above and belowground carbon storage potential of a silvopastoral system and compared to a conventional open pasture system in two sites of Chiapas, Mexico. We established a total of 20 carbon monitoring plots, 10 plots for each system. All the trees of2.5cm DBH were measured within the plots of 1000m(2). Allometric equations were used to calculate biomass carbon stocks. Grass biomass, ground litter, and soil samples were collected from four random locations within the plot. We also calculated tree diversity and other ecological indices of the silvopastoral systems. The aboveground biomass carbon stocks in dispersed tree silvopastoral systems varied between 11.53 +/- 1.80 to 14.63 +/- 5.50Mg C ha(-1). Soil organic carbon concentrations were higher in silvopastoral systems while soil bulk density was higher in open pasture systems, both affecting the soil organic carbon storage. A total of 29 tree species were registered in the dispersed tree silvopastoral systems. The Sorenson's similarity index showed that the two study sites significantly differed in terms of their tree community compositions. Such differences were also observed in soil properties and carbon storage. We showed that there was a positive correlation between aboveground biomass and soil organic carbon concentrations. Further research is required to better understand the contributions of fine root and litter turnover on soil organic carbon storage in these systems.