2014. Long-term soil response to variable-retention harvesting in the EMEND (Ecosystem Management Emulating Natural Disturbance) experiment, northwestern Alberta. Can. J. Soil Sci. 94: 263Á279. We report on soil responses to variable-retention (VR) harvesting from a large-scale experiment ( 1000 ha). Samples were taken prior to treatment, and 1 and 6 yr after treatment under cover types representing the successional trajectory for boreal mixedwood forests in northwestern Alberta, Canada. Variable-retention harvesting at six overstoryretention levels [100 (control), 75, 50, 20, 10, and 0% (clearcut)] were applied to 10-ha experimental units under four cover types: deciduous-dominated (80Á95% trembling aspen); deciduous-dominated with coniferous understory (80Á95% trembling aspen with white spruce understory at 60Á80% of full stocking); mixed coniferous-deciduous (35Á65% of each); and coniferous-dominated (80Á95% white spruce). Only a few clear differences in soil properties attributable to VR harvesting were evident 6 yr post-harvest: (1) both extractable NH 4 -N in forest floor and 0Á7 cm mineral-soil, and forest floor exchangeable K decreased with increasing canopy removal, and (2) forest floor exchangeable Ca increased with canopy removal. There was a decreasing trend in forest floor and mineral soil C (kg ha (1 ) in undisturbed stands between 1998 and 2005. Differences in soil properties among cover types included higher pH and N concentration in forest floors, and higher cation exchange capacity and exchangeable Ca and Mg in mineral soils in deciduous-dominated stands. Deciduous-dominated stands appear to have distinct soil properties that change under stand development. . et Prescott, C. 2014. Re´percussions a`long terme du re´gime de coupe a`re´tention variable sur le sol, dans le cadre de l'expe´rience EMEND (Ecosystem Management Emulating Natural Disturbance) mene´e dans le nord-ouest de l'Alberta. Can. J. Soil Sci. 94: 263Á279. Les auteurs pre´sentent les re´percussions du re´gime de coupe ar e´tention variable (RV) sur le sol, dans le cadre d'une expe´rience de grande envergure ( 1 000 ha). Les e´chantillons ont e´teṕ re´leve´s avant le traitement ainsi qu'un an et six ans apre`s le traitement, sous un couvert forestier correspondant aux stades successifs d'une foreˆt bore´ale mixte, dans le nord-ouest de l'Alberta, au Canada. Des parcelles expe´rimentales de 10 ha ont e´te´soumises a`un re´gime de coupe selon six niveaux de re´tention de l'e´tage dominant (100 % [te´moin], 75 %, 50 %, 20 %, 10 % et 0 % [coupe a`blanc]). Le couvert forestier e´tait compose´de quatre types : arbres a`feuilles caduques dominants (80 a`95 % de trembles); arbres a`feuilles caduques dominants avec sous-e´tage de conife`res (80 a`95 % de trembles et 60 a`80 % de la surface du sous-e´tage occupe´par l'e´pinette blanche); foreˆt mixte de conife`res et d'arbres a`feuilles caduques (35 a6 5 % dans chaque cas); conife`res dominants (80 a`95 % d'e´pinettes blanches). Seules quelques nettes diffe´rences dans les proprie´te´s du sol ...