Linking litter decomposition of above‐ and below‐ground organs to plant–soil feedbacks worldwide

Abstract

Summary 1.Conceptual frameworks relating plant traits to ecosystem processes such as organic matter dynamics are progressively moving from a leaf-centred to a whole-plant perspective. Through the use of meta-analysis and global literature data, we quantified the relative roles of litters from above-and below-ground plant organs in ecosystem labile organic matter dynamics. 2.We found that decomposition rates of leaves, fine roots and fine stems were coordinated across species worldwide although less strongly within ecosystems. We also show that fine roots and stems had lower decomposition rates relative to leaves, with large differences between woody and herbaceous species. Further, we estimated that on average below-ground litter represents approximately 33 and 48% of annual litter inputs in grasslands and forests, respectively.3. These results suggest a major role for below-ground litter as a driver of ecosystem organic matter dynamics.We also suggest that, given that fine stem and fine root litters decompose approximately 1.5 and 2.8 times slower, respectively, than leaf litter derived from the same species, cycling of labile organic matter is likely to be much slower than predicted by data from leaf litter decomposition only. Synthesis.Our results provide evidence that within ecosystems, the relative inputs of above-versus belowground litter strongly control the overall quality of the litter entering the decomposition system. This in turn determines soil labile organic matter dynamics and associated nutrient release in the ecosystem, which potentially feeds back to the mineral nutrition of plants and therefore plant trait values and plant community composition.

Soil CO<sub>2</sub> efflux from mountainous windthrow areas: dynamics over 12 years post-disturbance

“…Whether this 12-year-old windthrow area acts as a C sink or source cannot be assessed with our data. Rhizosphere respiration will contribute a large share of the overall F soil (Chen et al, 2006;Subke et al, 2006), and the dense grass cover produces comparatively high amounts of above-and below-ground litter (Freschet et al, 2013). Therefore, it is likely that the old windthrow area is losing comparatively less C than the more recently disturbed areas.…”

New Multicentury Evidence for Dispersal Limitation during Primary Succession

“…1), allowing more time for C to accumulate (Percival et al 2000). Greater soil C in the foreland evergreen sere may also be related to the low quality of litter from the dominant evergreen woody species, which is high in lignin and suberin and tends to form recalcitrant organic matter (Hobbie and Gough 2004;Freschet et al 2013). Analysis of quality and age of the soil C could clarify mechanisms underlying successiondriven sequestration.…”

Characteristics of Fine Roots of Pinus massoniana in the Three Gorges Reservoir Area, China

“…Fine root decomposition provides a major pathway for nutrient cycling and energy flow in forest ecosystems [12,13]. Research shows that, compared to aboveground leaf litter, belowground fine roots are continuously growing, dying, and decomposing, which contributes to increase soil organic matter content, especially in deep soil, and provides a major route for ecosystem C and nutrient input [14,15].…”