Effects of thinning intensity on fine root biomass and morphological characteristics of middle-aged Pinus tabulaeformis plantations in the Huanglong Mountains

A study on the Huanglong Scenic and Historic Interest Area reveals that moderate thinning intensity (retaining a canopy closure of 0.7) maximizes fine root biomass, root length density, and surface area density in middle-aged Pinus tabulaeformis plantations, promoting optimal tree growth by efficiently utilizing site resources. The research employed root auger sampling across three soil layers (0-20 cm, 20-40 cm, and 40-60 cm) to assess fine root biomass and morphological traits under four thinning intensities: control, light, moderate, and heavy. Results showed that while fine root biomass initially increased with thinning intensity, it declined significantly under heavy thinning, particularly in the topsoil (0-20 cm). Moderate thinning also enhanced specific root length and surface area, benefiting smaller diameter roots (0-1.0 mm) more than larger ones (1.0-2.0 mm). This finding underscores the ecological balance required to sustain healthy Pinus tabulaeformis forests in the Huanglong Mountains.

YOU Jianjian, 尤健健, ZHANG Wenhui, 张文辉, DENG Lei, 邓磊, YU Biyun, 余碧云, LI Gang, 李罡, HE Ting, 何婷, & FAN Rongrong, 樊蓉蓉. (2017). Effects of thinning intensity on fine root biomass and morphological characteristics of middle-aged Pinus tabulaeformis plantations in the Huanglong Mountains. Acta Ecologica Sinica, 37(9). https://doi.org/10.5846/stxb201601150100