Rapid mixed forest encroachment and the expansion of red maple

• Published in: Botany Vol. 100; no. 8; pp. 677 - 690
• Main Authors: Lavoie, Martin, Grondin, Pierre, Caron, Catherine, Larouche, Alayn C, Poirier, Veronique
• Format: Journal Article
• Language: English
• Published: NRC Research Press 01.08.2022
• Subjects: Analysis; Dendrochronology; Distribution; Environmental aspects; Peat-bogs; Plant succession; Red maple; Canada
• ISSN: 1916-2790
• DOI: 10.1139/cjb-2021-0171

Some ombrotrophic peatlands in temperate regions have been characterized by a process of rapid densiflcation of their forest cover for several decades. This phenomenon is particularly marked in southern Quebec (Canada), where a number of peatlands now contain mixed forest stands. The present study aimed to document the woody encroachment dynamics of a peatland colonized by Larix laricina (Du Roi) K. Koch and Acer rubrum L. The specific objectives were to characterize the contemporary dynamics of the forest cover through analysis of dendrometric, dendrochronological, and aerial photographs, and to reconstruct the evolution of tree species present in situ since the peatland's origin through botanical identification of ligneous remains collected in excavations of the peat as well as macro fossil analysis of a sedimentary core. The vegetation cover underwent rapid transformation beginning in the 1970s, first by the densiflcation of L. laricina, followed by the expansion of A rubrum. This transformation followed several millennia during which the peatland continuously presented a shrub-dominated cover with a few scattered coniferous trees. The rapid expansion of a mixed forest cover is a unique event in the peatland's history. Acer rubrum progressively replaced L. laricina and, in the more or less long-term, should become the dominant species.