title: Functional responses and resilience of boreal forest ecosystem after reduction of deer density.
abstract: The functional trait-based approach is increasingly used to predict responses of ecological communities to disturbances, but most studies target a single taxonomic group. Here, we assessed the resilience of a forest ecosystem to an overabundant herbivore population by assessing changes in 19 functional traits for plant, 13 traits for ground beetle and 16 traits for songbird communities after six years of controlled browsing on Anticosti Island (Quebec, Canada). Our results indicated that plants were more responsive to 6 years of reduced browsing pressure than ground beetles and songbirds. However, co-inertia analysis revealed that ground beetle communities responded in a similar way than plant communities with stronger relationships between plant and ground beetle traits at reduced deer density, a pattern not detected between plant and songbird. High deer density favored plants species that reproduce vegetatively and with abiotic pollination and seed dispersal, traits implying little interaction with animal. On the other hand, traits found at reduced deer density mostly involved trophic interaction. For example, plants in this treatment had fleshy fruits and large seeds dispersed by birds or other animals whereas ground beetle species were carnivorous. Overall, our results suggest that plant communities recovered some functional components to overabundant herbivore populations, since most traits associated with undisturbed forests were reestablished after six years of deer reduction. The re-establishment of functional plant communities with traits involving trophic interaction induces changes in the ground-beetle trait community, but forest structure remains likely insufficiently heterogeneous to shift the songbird trait community within six years.
authors.affiliation: Chaire de recherche industrielle CRSNG-Produits Forestiers Anticosti, Département de biologie, Université Laval, Québec, Québec, Canada ; Centre d'études nordiques, Université Laval, Québec, Québec, Canada ; Québec Centre for Biodiversity Science, McGill University, Montréal, Québec, Canada.
authors.forename: Marianne
authors.initials: M
authors.lastname: Bachand
authors.affiliation: Chaire de recherche industrielle CRSNG-Produits Forestiers Anticosti, Département de biologie, Université Laval, Québec, Québec, Canada ; Québec Centre for Biodiversity Science, McGill University, Montréal, Québec, Canada ; Institut de recherche en biologie végétale, Jardin Botanique de Montréal, Montréal, Québec, Canada.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Pellerin
authors.affiliation: Swiss Federal Research Institute WSL, Bellinzona, Switzerland.
authors.forename: Marco
authors.initials: M
authors.lastname: Moretti
authors.affiliation: Great Lake Forestry Centre, Canadian Forest Service, Sault-Sainte-Marie, Ontario, Canada.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Aubin
authors.affiliation: Chaire de recherche industrielle CRSNG-Produits Forestiers Anticosti, Département de biologie, Université Laval, Québec, Québec, Canada ; Centre d'études nordiques, Université Laval, Québec, Québec, Canada.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Tremblay
authors.affiliation: Chaire de recherche industrielle CRSNG-Produits Forestiers Anticosti, Département de biologie, Université Laval, Québec, Québec, Canada ; Centre d'études nordiques, Université Laval, Québec, Québec, Canada.
authors.forename: Steeve D
authors.initials: SD
authors.lastname: Côté
authors.affiliation: Chaire de recherche industrielle CRSNG-Produits Forestiers Anticosti, Département de biologie, Université Laval, Québec, Québec, Canada ; Centre d'études nordiques, Université Laval, Québec, Québec, Canada ; Québec Centre for Biodiversity Science, McGill University, Montréal, Québec, Canada.
authors.forename: Monique
authors.initials: M
authors.lastname: Poulin
mesh_terms: D000704:Analysis of Variance; D063147:Animal Distribution / Q000502:physiology; D000818:Animals; D001517:Coleoptera / Q000502:physiology*; D003670:Deer / Q000502:physiology*; D017753:Ecosystem; D062312:Islands; D063148:Plant Dispersal / Q000502:physiology; D011157:Population Dynamics; D011792:Quebec; D012098:Reproduction; D012639:Seeds / Q000033:anatomy & histology / Q000502:physiology*; D020308:Songbirds / Q000502:physiology*; D014197:Trees / Q000502:physiology*