Organic Carbon Accumulation in Topsoil Following Afforestation with Willow: Emphasis on Leaf Litter Decomposition and Soil Organic Matter Quality

Abstract

Short-rotation intensive cultures (SRICs) of willows can potentially sequester carbon (C) in soil. However, there is limited information regarding the factors governing soil organic C (Corg) accumulation following afforestation. The objectives of this study were to: (i) determine whether willow leads to Corg accumulation in the topsoil (0-10 cm) two to six years after establishment in five SRICs located along a large climatic/productivity gradient in southern Quebec, and (ii) assess the influence of leaf litter decomposition and soil organic matter (OM) quality on Corg accumulation in the topsoil. Topsoil Corg concentrations and pools under SRICs were, on average, 25% greater than reference fields, and alkyls concentrations were higher under SRICs. On an annualized basis, Corg accumulation rates in the topsoil varied between 0.4 and 4.5 Mg ha −1 yr −1 .Estimated annual litterfall C fluxes were in the same order of magnitude, suggesting that SRICs can accumulate Corg in the topsoil during early years due to high growth rates. Leaf litter decomposition was also related to Corg accumulation rates in the topsoil. It was positively correlated to growing season length, degree-days, and growing season average OPEN ACCESSForests 2015, 6 770 air and topsoil temperature (r > 0.70), and negatively correlated to topsoil volumetric water content (r = −0.55). Leaf litter decomposition likely occurred more quickly than that of plants in reference fields, and as it progressed, OM became more decay resistant, more stable and accumulated as Corg in the topsoil.

Impact of short-rotation willow as riparian land-use practice on soil organic carbon fractions and composition from two contiguous wetland systems in the prairie pothole region

“…The quality, function, and biochemical stability of SOC depend on the relative abundance of soil LC versus RC functional groups (Beer et al 2008). As the soil organic matter (SOM) under different vegetation types from contrasting land-use practices decomposes, the chemical composition of SOC changes (La eur et al 2015;Deng et al 2019). Advanced analytical techniques such as Fourier Transform Infrared (FTIR) spectroscopy can reveal the biochemical characteristics at molecular-scale and relative abundance of C compounds (i.e., polysaccharides, phenolic, amides, aromatic, carboxylic) via the ratios of RC and LC fractions (Calderón et al 2013).…”

The effects of afforestation on soil bacterial communities in temperate grassland are modulated by soil chemical properties

“…Grassland afforestation is an artificial and direct change in vegetation that alters both the above- and underground ecosystems, including abiotic changes (Li et al, 2016; Peng et al, 2014; Khamzina, Lamers & Martius, 2016; Lafleur et al, 2015), biotic changes (Ma et al, 2013; Márquez et al, 2015; Pedley et al, 2014; Gunina et al, 2017; Šnajdr et al, 2013; Xiao et al, 2017), and ecological function changes (Lu et al, 2017; Ren et al, 2016; Cibils et al, 2015). Land use is a significant determinant of runoff and soil redistribution processes (Arnáez et al, 2015), and soil microbial species responses may be sensitive to compositional changes in both species and ecological functions (Xiao et al, 2017).…”

Soil Enzyme Activity as Affected by Land-Use, Salinity, and Groundwater Fluctuations in Wetland Soils of the Prairie Pothole Region

“…However, several studies on SRW suggested con icting results regarding SOC accumulation compared to other land-use practices. For example, the topsoil SOC increased under SRW plantation, on former agricultural land compared to conventional AC(Dimitriou et al 2012), adjoining agricultural elds(La eur et al 2015)…”