Abstract: Fine roots are the main organ for plants to absorb nutrients and water, and their decomposition  is an important pathway for soil nutrient return. Studying the stoichiometric characteristics of fine roots is of great significance for understanding plant-soil nutrient cycle in forest ecosystems. This study focused on the middle-aged natural Mongolian oak forest, natural broad-leaved mixed forest and larch plantation in Bajiazi Forestry Bureau, Jilin Province. Based on the stand survey data of 15 plots of 30 m × 30 m, the C, N, P stoichiometric characteristics of fine roots and soils (0-20 cm) in different stand types and their relationships were analyzed. The results showed that fine-root and soil C, N, P stoichiometric characteristics differed across different stands (P<0.05). Fine roots of all the three stand types were limited by N. Soil nutrients were rich in the natural broad-leaved mixed forest, but soil P of the natural Mongolian oak forest were relatively poor. The correlations between fine-root and soil C-N-P stoichiometric characteristics were significantly higher in larch plantation and natural broad-leaved mixed forest than that in the natural Mongolian oak forest. As for the three stand types, fine-root C∶N, C∶P, and C were more affected by soil C-N-P stoichiometric characteristics with soil C∶P as the major affecting factor. Our results provide a certain theoretical basis for soil nutrient management and sustainable forest management of natural Mongolian oak forest, natural broad-leaved mixed forest and larch plantation in Changbai Mountain forested area.

Key words: stand type, fine root, soil, stoichiometric characteristics, correlation analysis, redundancy analysis