This is a dataset of sapling regeneration within canopy gaps in a temperate montane riparian forest. The followings are details of each file. GapSeedlings_v1.0.0.csv Plot Integer. The ID of plots, some plots include more than one gap. Gap Factor. The ID of gaps. Quadrat Integer. The ID of quadrats within a gap. stemID Character. The ID of stems. Sp. Factor. The species names. Family Factor. The family name of the species. Substrate Factor. Established substrates. NA means that it was not recorded. Heightyyyy Numeric. Vertical heights of trees (cm) in yyyy. The individuals with CensusIn2020 = 0, their Height2020 is NA because they had not been censused in 2020. Lengthyyyy Numeric. Length of trees (cm) in yyyy. The individuals with CensusIn2020 = 0, their Length2020 is NA because they had not been censused in 2020. DBH1_yyyy, DBH2_yyyy Numeric. Diameter at breast height (mm) in yyyy. DBH1 and DBH2 were measured to cross at right angles. The individuals with CensusIn2020 = 0, their DBH2020_1 and DBH2020_2 are NA because they had not been censused in 2020. Cmtyyyy Character. Comments in yyyy. CensusIn2020 Factor. 1 means that the plot was censused in 2020, 0 does not. Map_Gaps.pdf p. 1: The overall picture of the positional relations between each gap. pp. 2-19: The details of gaps. Metadata_GapSeedlings.txt Metadata of "GapSeedlings_v0.1.0.csv". It is the same as this description.