Soil Respiration and Its Seasonal Variation among Five Young Plantations in South China

Abstract:

In order to understand the mechanisms of soil carbon sequestration of plantations in South China, the total soil respiration (R_s) and autotrophic respiration (R_a) and their seasonal dynamics of five plantations in Heshan, Guangdong at 2-5-year-old were studied from 2007 to 2012. The plantations include Eucalyptus urophylla plantation, 30 species mixed plantation, 10 species mixed plantation Castanopsis hystrix plantation, and Acacia crassicarpa plantation. The results showed that average R_s, R_a and contribution rate of R_a to R_s (RC) of these plantations ranged within 81.3-103.9 mg C m^-2h^-1, 11.2-22.3 mg C m^-2h^-1, and 12.4%-26.9%, respectively. The average R_s in wet season of these plantations were 311.4% higher than that in dry season; while R_a and RC had not significant difference between wet and dry seasons. The soil temperature in wet season had significant relation with R_s among five plantations, which explained the variation of R_s for 90.2%, but they had no relation in dry season. The difference of microenvironment and soil condition among these young plantations was no obvious, in which soil was still restoring from disturbance, so that soil respiration had no significant difference among five plantations.