Reduced postfire tree regeneration along a boreal forest-forest-tundra transect in northern Quebec

Journal Article · Mon Apr 01 00:00:00 EST 1991 · Ecology; (United States)

DOI:https://doi.org/10.2307/2937202· OSTI ID:5720201

Sirois, L; Payette, S ^[1]

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1. Univ. Laval, Sainte-Foy, Quebec (Canada)

The large 1950s fires that burned > 5,500 km{sup 2} of land across a south-to-north climatic gradient in northern Quebec provide an opportunity to evaluate the role of fire in forest-tundra development on a demographic basis. The tree population density before and {approx} 30 yr after fire was estimated by censusing trees in plots of 400 m{sup 2} located in upland and lowland within four representative ecoregions of northern Quebec. The analysis of tree recruitment before and after fire, in 410 randomly selected sites along a transect crossing the upper boreal forest and forest-tundra zones, indicated that wildfires induced substantial depletion of tree populations. Taken as a whole, fires have significantly reduced the density of black spruce populations in forest-tundra uplands, but not in the lowlands. Sustained reduction of tree population density after several destructive fires appears as one of the main deforestation processed in the subarctic zone. This leads to the patchy distribution of forest stands and scattered tree populations typical of the forest-tundra biome. Comparisons with paleoecological data suggest that the impact of the 1950s fires contributed to the expansion of the forest tundra into the upper boreal forest. The ecological impact of these fires was probably similar to those fires responsible for development of the forest tundra during the Holocene. It is suggested that the fire-climate interaction should be considered in order to predict the ecological impact of warming climate on high-latitude forest ecosystems.

• OSTI ID: 5720201
• Journal Information: Ecology; (United States), Vol. 72:2; ISSN 0012-9658
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
FIRES
BIOLOGICAL EFFECTS
FORESTS
ECOLOGY
BIOLOGICAL STRESS
CLIMATES
DEFORESTATION
GREENHOUSE EFFECT
LICHENS
PALEOCLIMATOLOGY
POPULATION DENSITY
QUEBEC
SPRUCES
ALGAE
CANADA
CLIMATIC CHANGE
CONIFERS
DEVELOPED COUNTRIES
EUMYCOTA
FUNGI
NORTH AMERICA
PALEONTOLOGY
PINOPHYTA
PLANTS
TREES
540110*