[Gap features and renewal dynamics in secondary natural Pinus tabulaeformis forest in hilly loess region].

Taking the secondary natural Pinus tabulaeformis forest in hilly loess region as research object, the shape, size structure, distribution, gap-maker features, and renewal dynamics of gaps were investigated. The results showed that the areas of canopy gap (CG) and extended gap (EG) appeared to have a skewed and small gap- dominated distribution. The CGs had an average area of 31.