Information on forest plant communities of Central Canada collected during 1956-1995

Over a period of 40 years Paul F. Maycock (1930-2012) and associates surveyed 1391 stands of late-successional, natural forest throughout all vegetation zones of east central Canada, many in parks and remote areas. The group generated an enormous body of detailed quantitative information on forest communities of Ontario and Quebec, subsets of which have figured in various graduate theses and publications, one in a classic paper on southern deciduous forest. Comparable survey information was recorded in all locations through consistent use of the same quantitative field method, the Point-quarter system of vegetational analysis. Vegetationally and environmentally homogeneous forest stands of at least a few hectares each were selected in tracts of natural forest, and environmental features such as topography, moisture availability, soil texture, and pH were recorded in most of them. Vegetation was usually sampled at 40 points per site, with the area around each point apportioned into four imaginary quadrats by a pair of meter sticks crossed directly over the point. In each quadrat, the tree and sapling nearest the point was recorded, along with its distance to the point and, for trees, its basal area, generating a sample of 160 trees and saplings. Information provided consists of various statistics at the stand-level that, for trees, includes stem density and total basal area and percent contribution of each species to total basal area and stem density. For saplings, the percent contribution of each species to total sapling stem density is provided. Occurrences of understory plants, including tree seedlings, recorded within 1-m² plots at alternate sampling points, are expressed as the percentage of plots in which each species was encountered. A separate list was compiled of plant species noted in the stand, but not recorded in the sampling. When necessary, plants of uncertain identity were determined with input from taxonomic specialists, and 1248 plant taxa were encountered in the entire study. Approximately 30,000 voucher specimens were collected, which together with the database constitute a valuable resource for both ecological and systematic research in plant biology. Records of species in forest communities expand current knowledge of plant distributions, including occurrences within provincial parks and other protected areas. The dataset supplies context for determining the ecological significance of threatened forests, guiding judgments of which are in most urgent need of protection and prioritizing conservation efforts. Data not only document composition and structure at a point in time, but serve as a baseline against which reanalysis decades later can offer insight into stand dynamics. The data are available for reuse under CC BY 4.0 licensing. Please cite the data release on Figshare and this data paper when reusing the data.