Release efficiency of DOC, TDN and TDP
The release efficiency (VE ) against time was significantly fitted to the Michaelis-Menten equation (p< 0.05), as shown in the examples in Figure 1, except for TDN of aged oak (Quercus serrata ) and Japanese larch (Larix leptolepis ) leaf litter (Figure S1, S2, S3). TheV max estimated by fitting to the Michaelis−Menten equation exceeded 100% for TDP in leaf litter of Erman’s birch (Betula ermanii ), young oak (Quercus serrata ), Japanese larch and hinoki cypress (Chamaecyparis obtusa ). TheV max of TDP was higher than those for of DOC and TDN in all the leaf litter examined. However, the half saturation time of release efficiency (k ) was the shortest for DOC (2.41 days; Table S1), followed by TDN release (3.04 days; Table S1), and was the longest for TDP (16.99 days; Table S1). The V maxfor TOC, TDN, and TDP differed between the leaf litter types (Figure 2). Between broadleaf and coniferous leaf litter, the meanV max of DOC (mean V max = 22.54% and 19.37%, respectively) and TDN (meanV max = 5.20% and 2.10%, respectively) of broadleaf species was higher (t = 2.38, p < 0.01 and t = 7.44, p < 0.01, respectively). However, no significant difference was detected in V max of TDP between the broadleaf and coniferous species. We also examined the maximal release efficiency that was actually observed during the 28-day experiment (Max-VE ), which was, on average, 59.74 % for TDP across all species, and was also the highest among the elements, followed by that for DOC (20.76%), and the lowest for TDN (5.53%) (Table S1).