Faber-Langendoen D.,NatureServe |
Keeler-Wolf T.,Biogeographic Data Branch |
Meidinger D.,British Columbia Ministry of forests |
Tart D.,U.S. Department of Agriculture |
And 7 more authors.
Ecological Monographs | Year: 2014
A vegetation classification approach is needed that can describe the diversity of terrestrial ecosystems and their transformations over large time frames, span the full range of spatial and geographic scales across the globe, and provide knowledge of reference conditions and current states of ecosystems required to make decisions about conservation and resource management. We summarize the scientific basis for EcoVeg, a physiognomic-floristic-ecological classification approach that applies to existing vegetation, both cultural (planted and dominated by human processes) and natural (spontaneously formed and dominated by nonhuman ecological processes). The classification is based on a set of vegetation criteria, including physiognomy (growth forms, structure) and floristics (compositional similarity and characteristic species combinations), in conjunction with ecological characteristics, including site factors, disturbance, bioclimate, and biogeography. For natural vegetation, the rationale for the upper levels (formation types) is based on the relation between global-scale vegetation patterns and macroclimate, hydrology, and substrate. The rationale for the middle levels is based on scaling from regional formations (divisions) to regional floristic-physiognomic types (macrogroup and group) that respond to meso-scale biogeographic, climatic, disturbance, and site factors. Finally, the lower levels (alliance and association) are defined by detailed floristic composition that responds to local to regional topo-edaphic and disturbance gradients. For cultural vegetation, the rationale is similar, but types are based on distinctive vegetation physiognomy and floristics that reflect human activities. The hierarchy provides a structure that organizes regional/continental vegetation patterns in the context of global patterns. A formal nomenclature is provided, along with a descriptive template that provides the differentiating criteria for each type at all levels of the hierarchy. Formation types have been described for the globe; divisions and macrogroups for North America, Latin America and Africa; groups, alliances and associations for the United States, parts of Canada, Latin America and, in partnership with other classifications that share these levels, many other parts of the globe. © 2014 by the Ecological Society of America.
Pureswaran D.S.,Natural Resources Canada |
De Grandpre L.D.,Natural Resources Canada |
Pare D.,Natural Resources Canada |
Taylor A.,Natural Resources Canada |
And 4 more authors.
Ecology | Year: 2015
Climate change is altering insect disturbance regimes via temperature-mediated phenological changes and trophic interactions among host trees, herbivorous insects, and their natural enemies in boreal forests. Range expansion and increase in outbreak severity of forest insects are occurring in Europe and North America. The degree to which northern forest ecosystems are resilient to novel disturbance regimes will have direct consequences for the provisioning of goods and services from these forests and for long-term forest management planning. Among major ecological disturbance agents in the boreal forests of North America is a tortricid moth, the eastern spruce budworm, which defoliates fir (Abies spp.) and spruce (Picea spp.). Northern expansion of this defoliator in eastern North America and climateinduced narrowing of the phenological mismatch between the insect and its secondary host, black spruce (Picea mariana), may permit greater defoliation and mortality in extensive northern black spruce forests. Although spruce budworm outbreak centers have appeared in the boreal black spruce zone historically, defoliation and mortality were minor. Potential increases in outbreak severity and tree mortality raise concerns about the future state of this northern ecosystem. Severe spruce budworm outbreaks could decrease stand productivity compared with their occurrence in more diverse, southern balsam fir forest landscapes that have coevolved with outbreaks. Furthermore, depending on the proportion of balsam fir and deciduous species present and fire recurrence, changes in regeneration patterns and in nutrient cycling could alter ecosystem dynamics and replace black spruce by more productive mixedwood forest, or by less productive ericaceous shrublands. Long-term monitoring, manipulative experiments, and process modeling of climate-induced phenological changes on herbivorous insect pests, their host tree species, and natural enemies in northern forests are therefore crucial to predicting species range shifts and assessing ecological and economic impacts. © 2015 by the Ecological Society of America.
Lapointe J.,University of Québec |
Lapointe J.,Direction Of Lexpertise Energie Faune Forets Mines Territoire Of Labitibi Temiscamingue |
Imbeau L.,University of Québec |
Tremblay J.A.,Ministere du Developpement Durable |
And 2 more authors.
Auk | Year: 2013
Intensive agriculture, as is typical of corn and soybean production, may be responsible for declines in the abundance and diversity of farmland birds. In Quebec, the transition to intensive crops is evidenced by marked increases of corn and soybean fields. From 2008 to 2010, we used satellite telemetry to study use of corn (Zea mays) and soybean (Glycine max) fields, other farmlands, wetlands, urban areas, and other habitats by 10 female Peregrine Falcons (Falco peregrinus) of the anatum-tundrius complex, a taxon of "special concern" in Canada. We monitored females during the nesting season, from hatching of eggs to independence of young, but before the young dispersed away from the nest site. Adult females were less likely to use corn and soybean fields than the "other farmlands" and "other habitats" categories during the nestling stage and the first month after young fledged. Once young fledged, other farmlands and urban areas were more likely to be used than the "other habitats" category when females were hunting in the areas that were farthest from the nest. The expansion of corn and soybean fields in the Quebec agricultural landscape has occurred to the detriment of other crops and may contribute to the decline in quality of hunting habitat of Peregrine Falcons and other avian top predators. © 2013 by The American Ornithologists' Union. All rights reserved.
Grondin P.,Ministere des Ressources naturelles |
Gauthier S.,Natural Resources Canada |
Borcard D.,University of Montréal |
Bergeron Y.,University of Québec |
Noel J.,Ministere des Ressources naturelles
Landscape Ecology | Year: 2014
Traditional approaches to ecological land classification (ELC) can be enhanced by integrating, a priori, data describing disturbances (natural and human), in addition to the usual vegetation, climate, and physical environment data. To develop this new ELC model, we studied an area of about 175,000 km2 in the Abies balsamea-Betula papyrifera and Picea mariana-feathermoss bioclimatic domains of the boreal forest of Québec, in eastern Canada. Forest inventory plots and maps produced by the Ministère des Ressources naturelles du Québec from 1970 to 2000 were used to characterize 606 ecological districts (average area 200 km2) according to three vegetation themes (tree species, forest types, and potential vegetation-successional stages) and four sets of explanatory variables (climate, physical environment, natural and human disturbances). Redundancy, cluster (K-means) and variation partitioning analyses were used to delineate, describe, and compare homogeneous vegetation landscapes. The resulting ELC is hierarchical with three levels of observation. Among the 14 homogeneous landscapes composing the most detailed level, some are dominated by relatively young forests originating from fires dating back to the period centered on 1921. In others, forest stands are older (fires from the period centered on 1851), some are under the influence of insect outbreaks and fires (southern part), while the rest are strongly affected by human activities and Populus tremuloides expansion. For all the study area and for parts of it, partitioning reveals that natural disturbance is the dominant data set explaining spatial variation in vegetation. However, the combination of natural disturbances, climate, physical environment and human disturbances always explains a high proportion of variation. Our approach, called "ecological land classification of homogeneous vegetation landscapes", is more comprehensive than previous ELCs in that it combines the concepts and goals of both landscape ecology and ecosystem-based management. © 2013 Springer Science+Business Media Dordrecht.
Bose A.K.,University of Québec |
Harvey B.D.,University of Québec |
Brais S.,University of Québec |
Beaudet M.,Ministere des Ressources Naturelles |
Leduc A.,University of Quebec at Montréal
Forestry | Year: 2014
Over the last 25 years, greater understanding of natural dynamics in the boreal forest has led to the integration of forest ecosystem management principles into forest policy of several Canadian provinces and, in turn, to greater interest in developing silvicultural treatments that are grounded in natural stand-level dynamics - often referred to as natural disturbance-based silviculture. As a result, alternative silvicultural practices including variants of partial cutting are increasingly being applied in the boreal forest as an approach to balancing economic and ecological management objectives. While the numerous benefits of partial cutting reported in the literature are acknowledged, the objective of this paper is to provide an overview of factors or constraints that potentially limit the application of these practices in boreal Canada in the context of forest ecosystem management and natural disturbance-based silviculture. Among constraining factors, numerous studies have reported elevated mortality rates of residual stems following partial cutting, initial growth stagnation of residual trees, problems related to recruitment of desirable species and, on certain flat or lowland sites, risks of long-term decline in site and stand productivity. A number of operational challenges to partial cutting in the boreal forest are also presented and several avenues of research are proposed. © 2013 Institute of Chartered Foresters, All rights reserved. For Permissions, please e-mail: email@example.com.
Tremblay S.,Ministere des Ressources naturelles |
Ouimet R.,Ministere des Ressources naturelles
Forests | Year: 2013
The objective of this study was to compare organic carbon (C) accumulation in plantations (PL) and natural succession (NS) established on fallow lands along a 50-year chronosequence in the eastern mixed forest subzone of Quebec (Canada). Above- and below-ground woody biomass were estimated from vegetation measurement surveys, and litter and soil (0-50 cm depth) C from samplings. At the year of abandonment, total C content of both PL and NS sites averaged 100 ± 13 Mg C ha-1. Over 50 years, total C content doubled on NS sites and tripled on PL sites (217.9 ± 28.7 vs. 285.7 ± 31.0 Mg ha-1) with respect to fallow land. On NS sites, the new C stocks accumulated entirely in the vegetation. On PL sites, C accumulated mostly in the vegetation and to a lesser extent in the litter, whereas it decreased by a third in the soil. As a result, the net C accumulation rate was 1.7 ± 0.7 Mg ha-1 yr-1 greater on PL sites than on NS sites over 50 years. By the 23rd year, PL sites became greater net C sinks than NS sites in the fallow lands of the study area, even with the loss of soil C. © 2013 by the authors.
Prevost M.,Ministere des Ressources naturelles |
Gauthier M.-M.,Ministere des Ressources naturelles
Forest Ecology and Management | Year: 2013
We evaluated the effectiveness of the regular shelterwood system in mitigating water table rise and regenerating a new cohort while favoring red spruce (Picea rubens Sarg.) in an 80-year-old, red spruce - balsam fir (Abies balsamea (L.) Mill.) lowland site. We used an experimental design established in 1994, with four completely randomized blocks and five treatments (uncut control, low, moderate, and heavy shelterwood cuttings, and clearcutting). In 2006, final overstory removal was carried out in the three shelterwoods and we monitored the first five growing seasons after treatment. Results showed that final cut did not lead to significant watering-up during the 2006-2010 period compared to levels measured in 1999, but water table levels did not fully recover from shelterwood cutting or clearcutting compared to precut levels measured in 1994. Under conditions of abundant seed supply, poor drainage, and low herbaceous and noncommercial woody competition, clearcutting (0.25. ha patches) provided the best red spruce cohort in terms of regeneration density, stocking, and growth. Balsam fir and red maple (Acer rubrum L.) regeneration was abundant in both silvicultural systems. Regeneration density and stocking of red spruce, balsam fir, and all commercial broadleaf species were generally lower inside logging trails than between trails, likely due to disturbance by machinery. For poorly-drained lowland sites, findings indicate patch clearcutting may be more effective in regenerating red spruce than the regular shelterwood system. © 2012 Elsevier B.V.
Prevost M.,Ministere des Ressources naturelles |
Dumais D.,Ministere des Ressources naturelles
Canadian Journal of Forest Research | Year: 2013
Estimating residual tree survival and growth is crucial for evaluating the overall merit of partial harvesting. In this case study, we present the effects of different cutting intensities (0%, 40%, 50%, and 60% of merchantable (diameter at breast height ≥ 9.1 cm) basal area (BA)) on the response of residual trees in two mixed yellow birch (Betula alleghaniensis Britt.)-conifer stands in eastern Quebec, Canada. Primarily aimed at promoting regeneration establishment, the experiment was conducted in two sites 90 km apart (Armagh and Duchesnay), each one containing four replicates of treatments in a randomized block design. Mortality after cutting decreased with increasing BA removal, but losses were two to three times higher at Armagh (62-138 stems/ha) than at Duchesnay (22-88 stems/ha). Loss of conifer stems involved primarily balsam fir (Abies balsamea (L.) Mill.) under natural conditions (control), whereas fir and red spruce (Picea rubens Sarg.) were equally affected in partial cuts. Red maple (Acer rubrum L.) and paper birch (Betula papyrifera Marsh.) were lost regardless of treatment. As a whole, growth in merchantable BA increased with cutting intensity. Uniform partial cuts produced good BA growth response from conifers at Armagh (0.27-0.28 m2·ha-1·year-1) and from hardwoods at Duchesnay (0.16-0.25 m2·ha-1·year-1), whereas BA growth was negligible for both species groups in the control. We examine the role of species composition and stand structure before cutting in the response of residual trees.
Dumais D.,Ministere des Ressources naturelles |
Prevost M.,Ministere des Ressources naturelles
Tree Physiology | Year: 2014
We examined the ecophysiology and growth of 0.3-1.3 m tall advance red spruce (Picea rubens Sarg.) and balsam fir (Abies balsamea [L.] Mill.) regeneration during a 5-year period following the application of different harvest types producing three sizes of canopy openings: (i) small gaps (<100 m2 in area; SMA) created by partial uniform single-tree harvest; (ii) irregular gaps of intermediate size (100-300 m2; INT) created by group-selection harvest (removal of groups of trees, mainly balsam fir, with uniform partial removal between groups); and (iii) large circular gaps (700 m2; LAR) created by patch-selection harvest (removal of trees in 30-m diameter circular areas with uniform partial removal between gaps). An unharvested control (CON) was monitored for comparison. At the ecophysiological level, we mainly found differences in light-saturated photosynthesis of red spruce and specific leaf area of balsam fir among treatments. Consequently, we observed good height growth of both species in CON and INT, but fir surpassed spruce in SMA and LAR. Results suggest that intermediate 100-300 m2 irregular openings create microenvironmental conditions that may promote short-term ecophysiology and growth of red spruce, allowing the species to compete with balsam fir advance regeneration. Finally, results observed for spruce in large 700-m2 openings confirm its inability to grow as rapidly as fir in comparable open conditions. © 2014 The Author.
Paquette A.,University of Quebec at Montréal |
Girard J.-P.,Ministere des Ressources Naturelles |
Walsh D.,University of Quebec at Chicoutimi
Northern Journal of Applied Forestry | Year: 2011
Although studies in the past have reported that the deeper planting of conifers has no effect on seedling performance, most planting guidelines in use today still recommend that seedlings be planted to the rootcollar. Past studies were mostly observational, used bareroot seedlings, and often reported early results from just one or two depths of planting treatments. Most of the results available regarding planting depth for boreal species are anecdotal, although they are planted by the hundreds of millions every year. The present study reports no short-term (1 year) or long-term (15 to 19 years) negative effect of planting depth on the survival and height and diameter growth of black spruce, white spruce, and jack pine seedlings over three large, replicated experiments in the boreal forest of eastern and northern Quebec (eastern Canada). Four different depth treatments were compared, from manual planting at the rootcollar to the deepest mechanical planting treatment at 10 cm or more, making this the largest, longest-lasting study of its kind. Although, as expected, important differences in growth were present between species, all three commonly planted conifers reacted similarly to the planting depth treatments (no effect). This result can in part be attributed to an almost perfect control of frost heaving in the deepest two treatments. Planting depth effects were assessed using analysis of variance, multiple Tukey honestly significant difference, and uncorrected pairwise one-tailed t-tests to increase the probability of detecting a negative effect. Absolute differences and effect sizes (generally small and often positive with greater depths) were also analyzed. Copyright © 2011 by the Society of American Foresters.