Following the appointment of the new Cabinet, the Forest Sector now reports to the ministère des Ressources naturelles et des Forêts, while the Wildlife and Parks Sectors report to the ministère de l'Environnement, de la Lutte aux changements climatiques, de la Faune et des Parcs. Adjustments will be made to the website over time.

Back to publications

Is the past history of acidic deposition in eastern Canada reflected in sugar maple’s tree rings 87Sr/86Sr, Sr and Ca concentrations?

Summary

Published in Applied Geochemistry 125: 104860. https://doi.org/10.1016/j.apgeochem.2020.104860

How calcium (Ca) uptake by trees in eastern Canadian forests has responded to decades of atmospheric acid deposition and its sharp decrease that started three decades ago is still largely unknown. Here, we tested a novel approach based on the measurements of Ca and strontium (Sr) concentrations and Sr isotope signature (87Sr/86Sr ratio) in sequential extracts of sugar maple tree rings and soils to assess changes in Ca availability and sources through time. The study was conducted at three sites showing a gradient of one order of magnitude in soil mineral weathering fluxes and exchangeable pools of Ca. We found that wood Ca and Sr concentrations increased with Ca and Sr concentrations in the exchangeable fraction (NH4Cl extracts) of the top mineral soil across sites. In addition, wood 87Sr/86Sr ratio was strongly correlated with 87Sr/86Sr ratio of this soil fraction. Both Ca and Sr concentrations in the exchangeable fraction of the wood decreased from pith to bark at all sites, whereas no trend was observed for the wood residual fraction. This was interpreted as a result of radial mobility of Ca in sapwood rather than a decline in the uptake of Ca and Sr by tree roots over time. The 87Sr/86Sr ratio of tree rings slightly increased over time only at the site with the higher soil exchangeable Ca pool, suggesting an increase in the contribution of soil mineral weathering relative to atmospheric deposition. In contrast with our hypothesis, our results show i) no evidence of pronounced changes in the relative contribution of the atmospheric vs. soil mineral weathering Ca components over time at the site with the smallest soil exchangeable Ca pools; and ii) the difficulty of assessing the temporal changes in the availability and the sources of Ca from sequential extractions of the wood due to a dynamic exchange process of Sr (and therefore Ca) between the exchangeable and residual fractions of the wood.

Sector(s): 

Forests

Categorie(s): 

Scientific Article

Theme(s): 

Forestry Research, Forests, Silviculture

Departmental author(s): 

Bilodeau-Gauthier, Simon, Houle, Daniel

Author(s)

HOULE, Daniel, Charles MARTY, C. Gagnon, Simon Bilodeau-Gauthier, N. Bélanger

Year of publication :

2021

Format :

PDF

ISSN

0883-2927

Keywords :

dendrochimie, forêts tempérées, acidification du sol, érable à sucre, sylviculture et rendement des forêts naturelles - peuplements de feuillus, article scientifique de la recherche forestière, Acer saccharum, calcium, strontium, forestry research scientific article, silviculture and yield of natural forests - hardwood stands, dendrochemistry, temperate forests, soil acidification, sugar maple

Partagez