Infrared Thermal Profiles in Silvopastoral and Full-Sun Pastures in the Eastern Amazon, Brazil

Abstract

There is a great need to identify interactions among silvopastoral systems and microclimatic indicators that describe the effect of trees compared to conventional pasture systems without trees. The objective of this study was to evaluate thermal conditions in a silvopastoral system and a pasture area exposed to full sunlight in the eastern Amazon, Brazil. The silvopastoral system was composed of the forest tree species Bertholletia excelsa H.B.K., Dipteryx odorata (Aubl.) Willd, and Khaya grandifoliola C.DC.. During the monitoring period, a forest inventory was carried out that included 30 trees from each species for which thermal profiles were created using a high-precision thermographic camera. Near-infrared thermography showed a positive and direct correlation with dendrometric variables. Silvopastoral systems with K. grandifoliola reduced the heat profile the most compared to conditions in a pasture fully exposed to sunlight, which demonstrates the ecosystem service provided by trees for thermal regulation in these systems. The microclimatic conditions explain the greater presence of bovines in the silvopastoral system as they were most likely in search of the thermal comfort provided by the trees during the period of the highest daytime temperatures. The silvopastoral system benefits the caloric balance and thermal comfort of pasture animals.