Tree Species Impact on Soil Carbon Dynamics

Tree species exert a profound influence on the storage, stabilisation and turnover of soil organic carbon (SOC) through variations in litter quality, root traits, microbial interactions and soil fauna communities. Deciduous and coniferous species differ in litter chemistry, leading to distinct rates of decomposition and degrees of mineral-associated organic matter formation. Fine root turnover and mycorrhizal associations further regulate carbon inputs to the mineral soil horizon, while aboveground biomass and species mixtures alter microclimatic conditions that affect microbial activity. The interplay of species identity, functional traits and site properties determines both the quantity and persistence of SOC stocks across climatic gradients and soil textures. Understanding these dynamics is essential for predicting feedbacks to climate change and for designing silvicultural practices that enhance long-term carbon sequestration.

Research from Nature Portfolio

Recent studies have demonstrated that tree functional traits, standing biomass and species diversity collectively explain approximately half of the local variability in forest SOC. A global analysis revealed that traits related to tissue density and litter chemistry exert the strongest effects under boreal climates and on acidic, coarse-textured soils. Mixing species enhances SOC storage, provided mixed stands achieve biomass over-yielding relative to monocultures. The work proposes three key strategies to optimise the forest carbon sink at a local scale: increasing standing biomass, promoting species richness, and selecting species combinations based on trait–environment matching. This trait-based framework offers a predictive approach for forest management to bolster carbon sequestration under diverse site conditions.

Tree Species Impact on Soil Carbon Dynamics publication trend

The graph below shows the total number of articles in tree species impact on soil carbon dynamics across all publications each year (not limited to Nature Index journals).

Technical terms

Soil organic carbon (SOC): The total carbon stored in soil organic matter, including plant residues, microbial biomass and humified materials.

Mineral-associated organic matter (MAOM): Organic compounds bound to soil minerals, representing a stable fraction of SOC.

Functional traits: Measurable characteristics of trees, such as wood density or leaf litter nutrient content, that influence ecosystem processes.

Biomass over-yielding: The phenomenon where mixed-species stands produce more biomass than the average of their constituent monocultures.

Mycorrhizal association: Symbiotic relationships between fungal groups (arbuscular or ectomycorrhizal) and roots that affect nutrient uptake and carbon allocation.

Litter quality: The chemical composition of fallen leaves or needles, typically described in terms of nutrient and lignin content, which governs decomposition rates.

References

1. A northward range shift of sugar maple (Acer saccharum) in Eastern Canada should reduce soil carbon storage, with no effect on carbon stability. Geoderma (2023).
2. Tree biomass does not correlate with soil carbon stocks in forest‐tundra ecotones along a 1100 km latitudinal gradient in Norway. Ecography (2023).
3. Litter quality, mycorrhizal association, and soil properties regulate effects of tree species on the soil fauna community. Geoderma (2022).
4. Tree functional traits, forest biomass, and tree species diversity interact with site properties to drive forest soil carbon. Nature Communications (2022).