Do understory sapling respond to both light and below-ground competition?: a field experiment in a north-eastern American hardwood forest and a literature review Jean-Pierre Ricard, Christian Messier, Sylvain Delagrange and Marilou BeaudetAnn. For. Sci., 60 8 (2003) 749-756DOI: https://doi.org/10.1051/forest:2003069