Ectomycorrhizal colonization of Alnus acuminata Kunth in northwestern Argentina in relation to season and soil parameters Alejandra Becerra, Karin Pritsch, Nilda Arrigo, Martha Palma and Norberto Bartoloni Ann. For. Sci., 62 4 (2005) 325-332 DOI: 10.1051/forest:2005027