Leaf decomposition across broadleaf and conifer tree species in South Korea and its relation to root decay: effects of initial traits and microbiota

초록

Background and AimsLitter decomposition is an essential biogeochemical process for nutrient cycling and represents an important component of global carbon fluxes. We aimed to examine leaf decomposition rates of broadleaf (Quercus mongolica) and conifer tree species (Pinus densiflora, Pinus koraiensis, and Larix kaempferi) in relation to initial traits and microbiota. We also investigated the correlation between leaf and root decay rates across different species and root diameter classes.MethodsA 359-day litterbag decomposition experiment was conducted from December 5, 2022, to November 29, 2023. Initial leaf chemical traits (C, N, C:N, P, K, Mg, Ca, hemicellulose, cellulose, and lignin) and specific leaf area were determined. Organic soil (fermented and humic horizons) was sampled to analyze microbial communities. Further, we compared leaf decay with root decay data provided by a previous study.ResultsLeaf decomposition rates did not differ significantly among species, and leaf and root decomposition were not correlated. However, when both leaf and root litter were analyzed together, analyses revealed significant effects of litter type, species, and their interaction on k-values. In addition, several initial traits and microbial genera influenced k-values.ConclusionThe lack of correlation between leaf and root decay, together with the significant effects of litter type, species, and their interaction, suggests that leaf and root decomposition dynamics are species-specific rather than governed by a generalized relationship. Our results also support that litter quality and microorganisms are key determinants of decomposition. This study provides important insights into litter decomposition and highlights the complexity of decomposition processes.

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