Predicting Fine Root Decomposition from Functional Traits in 10 Temperate Tree Species

Abstract

Decomposition of plant roots and their related fungal mutualists is a fundamental process of ecosystem material cycles. Despite the fact that fine roots are the dominant source of soil organic carbon (SOC) storage, our understanding of the functional traits controlling fine root decomposition is still far from clear. In the present study, the decomposition of fine roots among four arbuscular mycorrhizal (AM) and six ectomycorrhizal (EM) species was studied in a temperate forest after 570 days of exposure. Our results showed that fine roots among AM species decomposed faster than EM species. Our findings further suggested that initial aluminum (Al) and manganese (Mn) concentrations were the best predictors for decomposition of fine roots among the traits that we measured. Initial cellulose concentration, carbon:nitrogen ratio (C:N), and lignin:N ratio were closely related to decomposition among AM species. In contrast, among EM species, initial phosphorus (P), calcium (Ca), and non–structural carbohydrate (NSC) concentrations were the best predictors of fine root decomposition. The initial concentrations of Na, Fe, NSC, cellulose, and hemicellulose were useful predictors of fine root decomposition across the 10 studied tree species.