Short‐term carbon emissions: Effect of various tree harvesting, transport, and tillage methods under a eucalyptus plantation

• Published in: Land degradation & development 2018-11, Vol.29 (11), p.3995-4004
• Main Authors: Fialho, Ricardo Cardoso, Silva Teixeira, Rafael, Teixeira, Ana Paula Mendes, Silva, Ivo Ribeiro
• Format: Article
• Language: English
• Subjects: 13C; Carbon dioxide; C–CH4; C–CO2; Design of experiments; eucalypt harvest residue; Eucalyptus; Experimental design; Fluxes; Harvesting; Methane; Organic carbon; Organic matter; Organic soils; Pasture; Plantations; Soil density; Soil moisture; soil organic carbon; Soil organic matter; Tillage
• ISSN: 1085-3278; 1099-145X
• DOI: 10.1002/ldr.3161

Eucalyptus forests stand out for their potential to sequestrate atmospheric CO2 in soil organic matter throughout their growth. Our study evaluated the harvesting and tillage effect in eucalyptus plantations to the soil CO2, 13C–CO2, and CH4 fluxes. This study was carried out in a eucalyptus plantation, on Typic Haplustox soil. The study used stands cultivated with eucalyptus at the end of the first rotation (7 years), established over degraded pastures. The effect of harvesting was assessed through comparisons of samples taken before and after harvesting with Feller + Skidder (F + S) and Harvester + Forwarder (H + F) methods and separate samples of plant rows (R) and plant interrows (IR). The effect of tillage was assessed through comparisons of R and IR samples taken before and after subsoiling tillage in areas harvested with F + S and H + F methods. A nested experimental design was used with eight replicates. The harvest operation (F + S and H + F methods) in eucalyptus plantations increased soil CO2 fluxes, which were primarily derived from eucalyptus materials (‘new C’). The F + S harvesting method resulted in the highest soil density and soil moisture reduction in the IR. The tillage operation (subsoiling) resulted in higher soil CO2 fluxes in eucalyptus plantations harvest with F + S and H + F methods. However, the H + F method preserved the older soil organic carbon (40.8% in R and 50.4% IR of C4–CO2). The soil in the eucalyptus plantations showed soil CH4 influxes, and the harvest and tillage (subsoiling) operations did not negatively affect the net soil CH4 influx in the studied eucalyptus plantations.