Fig. 2

Relative yield total for each species (a) and relative yield total for total standing fine root biomass (b) and in Pinus–Cinnamomum mixed stands at ages of 10, 24, and 45 years old stand age in comparison to monocultures (reference level = 1). Asterisks denote significant differences from 1 with t test or Mann–Whitney U test, P < 0.05. Each datum shows the mean ± SE