Avances en la estimación de los cambios en las existencias de carbono de un monte de reparo de Eucalyptus sp. en un sistema ganadero en el norte de Buenos Aires

Abstract

Shelter belts or small stands provide animal welfare on livestock farms (MR). They can be designed considering their capacity also as carbon sinks and to offset the emissions of a bovine livestock system. The objective of this work was to quantify the changes in the stocks of carbon (C), sequestered by commercial stands of Eucalyptus that fulfill the function of MR. A commercial plantation of 4.5 ha was used in the lowlands of the province of Buenos Aires, with relatively high (Al), medium (Me) and low (Ba) sectors. In 2017, a base pasture of wheatgrass (Thinopyrum ponticum) and 25 stands of 5 Eucalyptus cultivars with 300 plants each were implanted. In the fifth year, the diameter was measured at 1.3 meters above the ground in plots of each cultivar; Soil and forage biomass samples were taken in RM and pasture. The estimation of sequestered carbon was made using the IPCC 2006 Gain and Loss Method. At the fifth year, the estimated annual change in C of the MR (t CO2 ha-1year- 1) was 38.17 (±7.02), varying between cultivars: H105 (43.39 ±5.32); INTAGC12 36.55 (±2.07); INTAGC27 36.24 (±2.47); INTAGC9 31.01 (±2.36); INTAHSP216B 24.56 (±3.19) and between sectors: Al 57.6 (±3.33), Me 38.8 (±2.49) and Ba 16.7 (±1.58). The same differences were found in volumetric yield, between cultivars and between sectors. The MR pasture lost -2.31 (±1.82) t d.m ha-1year-1 (dry matter) due to the different shade of the cultivars. No differences were found in soil C between MR and pasture.

Los sistemas integrados han sido identificados como una estrategia para compensar las emisiones de gases de efecto invernadero (GEI) al adicionar el componente forestal al secuestro de C en pastura y suelo (de Figueredo, 2017). En los sistemas de cría (SCB) o sistemas de ciclo completo (SCC) de la región pampeana, habitualmente se incorporan cortinas forestales y montes de reparo (MR), para dotar de sombra y refugio al ganado. Sin embargo, no se diseñan con el objetivo potencial de compensar emisiones de carbono. Esto evidencia la necesidad de cuantificar el carbono retenido en los MR en los sistemas ganaderos de la región.