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

Abstract

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.

Effects of forest structure on litter production, soil chemical composition and litter-soil interactions

“…Litter in forest fragments is known to decompose more rapidly under a subtropical climate than under a tropical climate, which suggests an effect of climate (Scheer 2008;Terror et al 2011;) through precipitation seasonality in subtropical regions. However, leaf decomposition in exotic species from the same region was previously found to be slower than in this study (Sausen et al 2014;Vieira et al 2014).…”

“…Th e decomposition rate of litter varies with the quality of the substrate, and also with the amount and activity of decomposers (Xiaogai et al 2013), which are closely associated (Wardle et al 2006). Litter decomposition can also infl uence soil properties and alter the stability of soil organic C and cation exchange processes in plant-soil interactions (Sausen et al 2014).…”

“…Forest decomposition systems have been the focus of several studies in recent years (Pimenta et al 2011;Terror et al 2011;Wang et al 2013;Sausen et al 2014). However, the influence of species richness and litter composition on nutrient cycling remains a topic of hot debate (Szanser et al 2011).…”

A Complete Assessment of Carbon Stocks in Above and Belowground Biomass Components of a Hybrid Eucalyptus Plantation in Southern Brazil

“…Forest plantations play an important role in the global carbon cycle [3,4], as when forests grow, carbon is removed from the atmosphere and stored in the plants [5][6][7]. New forest establishment is of ecological, environmental, social, and economic value [6] and results in large amounts of C being sequestered [7][8][9], although trade-offs involving the impacts on hydrology and biogeochemistry should be taken into account [10]. Plantations can maximize carbon sequestration, but also have adverse side effects such as reduced stream flow [11] and decreased soil pH and base saturation [10].…”

“…Biomass allocation depends on the resources available at the site as well as the type of management [13], stand age [3,9], and rotation length [14]. Likewise, the accumulation of soil carbon depends on the type of land use [15,16], soil chemical and physical properties [8], climatic conditions [7], net primary productivity, fertilization, site preparation, and soil drainage [17].…”