Track 1-16: Production, Environment and Social Benefit of Agroforestry Systems

Description

Little information is available about carbon (C) sequestration potentials in ecosystems on Andisols of the Chilean Patagonia. This study was undertaken to measure the size of the C stocks in three predominant ecosystems: Pinus ponderosa-based silvopastoral systems (SPS), pine plantations (PPP) and natural pasture (PST), and to examine how clover (Trifolium spp.) affect tree growth and stocks of soil C. The C contents of trees and pasture were determined by destructive sampling and dry combustion. Soil samples were taken at 0-5, 5-20, 20-40 cm depths in order to determine soil C and N. For PPP and SPS, respectively, 38.4 and 53.1 kg/tree of total tree C were stored aboveground, whereas 21.3 and 23.4 kg/tree were stored belowground. Tree diameter at breast height increased 1 and 2 cm/year in PPP and SPS, respectively, and was significantly higher in SPS, an interesting value for the region. Tree growth in SPS was enhanced by lower tree competition and the additional soil N provided by the leguminous pasture, resulting in larger amounts of C being sequestered. Soil organic C (SOC) stocks at 0-40 cm depth were 193.76, 177.10 and 149.25 Mg/ha in SPS, PST and PPP, respectively. The conversion of PPP to SPS and PST to PPP resulted in an increase of 44.51 Mg/ha and a decrease of 27.85 Mg/ha in SOC, respectively, at 0-40 cm soil depth. A favourable micro-climate (air temperature, soil moisture) has been observed in SPS as well as a synergistic effect between trees and pasture.

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Productivity and Carbon Storage in Silvopastoral Systems with Pinus ponderosa and Trifolium spp. Plantations and Pasture on a Volcanic Soil in the Chilean Patagonia

Little information is available about carbon (C) sequestration potentials in ecosystems on Andisols of the Chilean Patagonia. This study was undertaken to measure the size of the C stocks in three predominant ecosystems: Pinus ponderosa-based silvopastoral systems (SPS), pine plantations (PPP) and natural pasture (PST), and to examine how clover (Trifolium spp.) affect tree growth and stocks of soil C. The C contents of trees and pasture were determined by destructive sampling and dry combustion. Soil samples were taken at 0-5, 5-20, 20-40 cm depths in order to determine soil C and N. For PPP and SPS, respectively, 38.4 and 53.1 kg/tree of total tree C were stored aboveground, whereas 21.3 and 23.4 kg/tree were stored belowground. Tree diameter at breast height increased 1 and 2 cm/year in PPP and SPS, respectively, and was significantly higher in SPS, an interesting value for the region. Tree growth in SPS was enhanced by lower tree competition and the additional soil N provided by the leguminous pasture, resulting in larger amounts of C being sequestered. Soil organic C (SOC) stocks at 0-40 cm depth were 193.76, 177.10 and 149.25 Mg/ha in SPS, PST and PPP, respectively. The conversion of PPP to SPS and PST to PPP resulted in an increase of 44.51 Mg/ha and a decrease of 27.85 Mg/ha in SOC, respectively, at 0-40 cm soil depth. A favourable micro-climate (air temperature, soil moisture) has been observed in SPS as well as a synergistic effect between trees and pasture.