Clay content drives carbon stocks in soils under a plantation of Eucalyptus saligna Labill. in southern Brazil

• Published in: Acta Botânica Brasílica 2014-06, Vol.28 (2), p.266-273
• Main Authors: Sausen, Tanise Luisa, Schaefer, Guilherme Frederico de Paula, Tomazi, Michely, Santos, Lívia Scheunemann dos, Bayer, Cimélio, Rosa, Luís Mauro Gonçalves
• Format: Article
• Language: English
• Subjects: decomposition; litter input; soil organic matter fractions; weathered soils
• ISSN: 0102-3306; 1677-941X; 0102-3306
• DOI: 10.1590/S0102-33062014000200013

Soil carbon accumulation is largely dependent on net primary productivity. To our knowledge, there have been no studies investigating the dynamics of carbon accumulation in weathered subtropical soils, especially in managed eucalyptus plantations. We quantified the seasonal input of leaf litter, the leaf decomposition rate and soil carbon stocks in an commercial plantation of Eucalyptus saligna Labill. in southern Brazil. Our goal was to evaluate, through multiple linear regression, the influence that certain chemical characteristics of litter, as well as chemical and physical characteristics of soil, have on carbon accumulation in soil organic matter fractions. Variables related to the chemical composition of litter were not associated with the soil carbon stock in the particulate and mineral fractions. However, certain soil characteristics were significantly associated with the carbon stock in both fractions. The concentrations of nutrients associated with plant growth and productivity, such as phosphorus, sulfur, copper and zinc, were associated with variations in the labile carbon pool (particulate fraction). Clay content was strongly associated with the carbon stock in the mineral fraction. The carbon accumulation and stabilization in weathered subtropical Ultisol seems to be mainly associated with the intrinsic characteristics of the soil, particularly clay content, rather than with the quantity, chemical composition or decomposition rate of the litter.