Relative importance of various regeneration mechanisms in different restoration stages of Quercus variabilis forest after selective logging

Aim of study: Quercus variabilis (Chinese cork oak) reproduces asexually and sexually. This study aimed to determine the status and growth of asexual and sexual recruits of Q. variabilis in different forest recovery stages. Area of study: Three selective logged stands and one unlogged stand in Q. variabilis forest, Shaanxi Province, China. Material and methods: Origin, number, basal diameter, height and size structure of Q. variabilis shoots (height <= 200 cm) were investigated in the plots of 5, 10, and 20-years post-logging stands and unlogged stand. Effects of recovery stage on the density and growth of the three original recruits (stump sprouts, stem base sprouts and true seedlings) were analysis by One-way ANOVA. Main results: Sprouts dominated logged stands, whereas true seedlings dominated unlogged stand, stem base sprouts only existed in 20-years post-logging and unlogged stands. Stump sprout density and sprout number per stump both declined with extended post-logging time. True seedlings density increased from 7 to 20 shoots/100 m(2) as the post-logging time extended, and peaked in unlogged stand (94 shoots/100 m(2)). An ongoing size structure was observed in true seedlings in all stands. Stump sprouts were taller and greater than true seedlings. Research highlights: Stump sprouts contributed more to Q. variabilis forest recovery in the early stage after disturbance. The contribution of true seedlings was limited in the same stage, but they were beneficial for population long-term development. Stem base sprouts were most likely to be a survival strategy rather than a reproductive strategy.