Surface soil carbon size–density fractions altered by loblolly pine families and forest management intensity for a Spodosol in the southeastern US

Abstract

The effects of genotypic differences on soil organic carbon (SOC) cycling and their interactions with forest management systems are poorly understood. This study was undertaken to examine the effects of family and family × management interactions on SOC and to evaluate the distribution of SOC across different size-density fractions in a forested Spodosol. The study site consisted of a 6-year-old loblolly pine plantation that was managed under two intensities (high and low level of fertilization and chemical understory control) and included three fullsib families (fast, medium and slow growers, designated a priori based on above ground growth). The fast growing family exhibited 59% higher C (p=0.04) than the slow growing family in the 2,000 to 250-μm light density fraction. The medium grower exhibited 8% higher aggregate C than the fast grower in the 250 to 150-μm medium density (p=0.05) and 2,000 to 250-μm heavy density (p=0.06) fractions. Family and management effects were detected among all three density fractions. The 2,000 to 250-μm medium density fraction contained the most C. A modified size-density fractionation and sonication procedure proved sensitive for detecting significant family and management effects in as few as 6 years. These results highlight the potential of genotypic deployment as a factor influencing C sequestration and the need to fully understand the long-term effects of genotypic differences and forest management activities on SOC pools.

Effects of forest conversion on soil labile organic carbon fractions and aggregate stability in subtropical China

“…In addition, losses of labile fraction organic C after forest transition mainly occurred in 0-10 cm topsoil. Our results are consistent with the previous findings (Guo and Gifford 2002;Chen et al 2004a;Sarkhot et al 2008).…”

Effect of Forest Structural Change on Carbon Storage in a Coastal Metasequoia glyptostroboides Stand

“…Some studies also found that the LFOC was higher at the soil surface, which was strongly related to root carbon inputs [45] and other organic residues accumulated in this layer. Our results are consistent with the previous findings [12, 46]. In this study, the higher LFOC at the 0–15 cm layer in the thinned and underplanted stands could be related to more root and litterfall carbon inputs (Table 2).…”

Black Spruce Soils Accumulate More Uncomplexed Organic Matter than Aspen Soils

“…To the best of our knowledge, this study is the first to specifically address the effect of forest types on SOC stabilization through soil aggregation and soil physical fractions in a natural ecosystem. The very few studies focusing on this topic took place in managed plantation systems (e.g., Blanco-Canqui et al, 2007;Gama-Rodrigues et al, 2010;Quideau et al, 1998;Saha et al, 2010;Sarkhot et al, 2008), where soil disturbance is high and naturally-associated understory is generally lacking. In addition, the tree species selected in these studies were mostly genetically improved species [e.g., loblolly pine {Pinus taeda L.) and hybrid poplar clones].…”