Skip to main content
SLU publication database (SLUpub)

Research article2010Peer reviewed

Does soil organic layer thickness affect climate-growth relationships in the black spruce boreal ecosystem?

Drobyshev Igor, Simard Martin, Bergeron Yves, Hofgaard Annika


The observed long-term decrease in the regional fire activity of Eastern Canada results in excessive accumulation of organic layer on the forest floor of coniferous forests, which may affect climate–growth relationships in canopy trees. To test this hypothesis, we related tree-ring chronologies of black spruce (Picea mariana (Mill.) B.S.P.) to soil organic layer (SOL) depth at the stand scale in the lowland forests of Quebec’s Clay Belt. Late-winter and early-spring temperatures and temperature at the end of the previous year’s growing season were the major monthly level environmental controls of spruce growth. The effect of SOL on climate–growth relationships was moderate and reversed the association between tree growth and summer aridity from a negative to a positive relationship: trees growing on thin organic layers were thus negatively affected by drought, whereas it was the opposite for sites with deep (>20–30 cm) organic layers. This indicates the development of wetter conditions on sites with thicker SOL. Deep SOL were also associated with an increased frequency of negative growth anomalies (pointer years) in tree-ring chronologies. Our results emphasize the presence of nonlinear growth responses to SOL accumulation, suggesting 20–30 cm as a provisional threshold with respect to the effects of SOL on the climate–growth relationship. Given the current climatic conditions characterized by generally low-fire activity and a trend toward accumulation of SOL, the importance of SOL effects in the black spruce ecosystem is expected to increase in the future


succession; dendroecology; paludification; soil conditions; climate change

Published in

2010, Volume: 13, number: 4, pages: 556-574

    UKÄ Subject classification

    Forest Science

    Publication identifier


    Permanent link to this page (URI)