Venier, L.A., Work, T.T., Klimaszewski, J., Morris, D.M., Bowden, J.J., Kwiaton, M.M., Webster, K., and Hazlett, P.
We tested the response of species composition of three dominant litter-dwelling arthropod taxa (carabid beetles, spiders, and rove beetles) to wildfire and harvest. This study was conducted in north-central Ontario (47[degrees]42'N, 83[degrees]36'W) in jack pine (Pinus banksiana Lamb.) dominated stands in 2013 using pitfall trapping. Using 222 species (12 015 individuals), we compared the effects of disturbance using recently burned (3 years since fire) and clearcut sites (3 years since harvest; tree length, full tree, stump removal, and blading), as well as older, closed-canopy stands that have regenerated following clearcutting (51 years since harvest) and fire (92 years since fire), with multivariate regression trees. Taxa were more similar in the three controls (including recent fire) than between controls and harvest treatments, with increased forest floor disturbance in harvested plots being a likely explanation. In addition, taxa were different in the younger (51 years) harvest-origin plots than in the older (92 years) fire-origin plots, suggesting that communities had not yet recovered from the harvest disturbance possibly due to insufficient coarse woody debris in the younger stand. These results indicate that forest management practices that match natural forest floor disturbance could ameliorate short-term effects, whereas the maintenance of more coarse woody debris could reduce the recovery time of epigaeic communities. Key words: natural disturbance emulation, ecosystem management, carabid beetle, rove beetle, ground spider. Nous avons etudie l'impact des feux de foret et de la recolte sur la composition en especes de trois taxons dominants d'arthropodes qui vivent dans la litiere (carabes, araignees et staphylins). Cette etude a ete realisee en 2013 dans le centre-nord de l'Ontario (47[degrees]42'N, 83[degrees]36'O), dans des peuplements domines parle pin gris (Pinus banksiana Lamb.), au moyen du piegeage dans des trappes. A l'aide de 222 especes (12 015 individus), nous avons compare les effets de la perturbation en utilisant des sites recemment brules (3 ans apres un feu) et des sites coupes a blanc (3 ans apres la recolte; bois en longueur, arbre entier, enlevement des souches et coupe a la cisaille), ainsi que des peuplements plus vieux a couvert ferme qui se sont regeneres apres une coupe a blanc (51 ans apres la recolte) ou un feu (92 ans apres le feu) en utilisant des arbres de regression multivariee. Les taxons etaient plus semblables dans les trois temoins (incluant le feu recent) que entre les temoins et les traitements impliquant une coupe, ce qui s'explique vraisemblablement par la perturbation accrue de la couverture morte dans les parcelles recoltees. De plus, les taxons etaient differents dans les parcelles plus vieilles (92 ans) issues de feux comparativement aux plus jeunes (51 ans) issues d'une coupe, ce qui indique que les communautes n'avaient pas encore recupere a la suite de la perturbation due a la recolte, probablement a cause du manque de debris ligneux grossiers dans le peuplement plus jeune. Ces resultats indiquent que les pratiques d'amenagement forestier qui correspondent a une perturbation naturelle de la couverture morte pourraient ameliorer les effets a court terme tandis que le maintien de plus de debris ligneux grossiers pourrait reduire la periode de recuperation des communautes epigees. [Traduit par la Redaction] Mots-cles: imitation des perturbations naturelles, amenagement de l'ecosysteme, carabe, staphylin, araignee qui vit au sol., 1. Introduction Ecological comparisons of resident biota between managed and naturally disturbed sites are the premise of natural disturbance based approaches to forest management. Natural disturbance based management is founded [...]