Skip to main content
Research article - Peer-reviewed, 2020

Driving factors of conifer regeneration dynamics in eastern Canadian boreal old-growth forests

Martin, Maxence; Girona, Miguel Montoro; Morin, Hubert

Abstract

Old-growth forests play a major role in conserving biodiversity, protecting water resources, and sequestrating carbon, as well as serving as indispensable resources for indigenous societies. Novel silvicultural practices must be developed to emulate the natural dynamics and structural attributes of old-growth forests and preserve the ecosystem services provided by these boreal ecosystems. The success of these forest management strategies depends on developing an accurate understanding of natural regeneration dynamics. Our goal was therefore to identify the main patterns and drivers involved in the regeneration dynamics of old-growth forests with a focus on boreal stands dominated by black spruce (Picea mariana(L.) Mill.) and balsam fir (Abies balsamea(L.) Mill.) in eastern Canada. We sampled 71 stands in a 2 200 km(2)study area located within Quebec's boreal region. For each stand, we noted tree regeneration (seedlings and saplings), structural attributes (diameter distribution, deadwood volume, etc.), and abiotic (slope and soil) factors. The presence of seed-trees located nearby and slopes having moderate to high angles most influenced balsam fir regeneration. In contrast, the indirect indices of recent secondary disturbances (e.g., insect outbreaks or windthrows) and topographic constraints (slope and drainage) most influenced black spruce regeneration. We propose that black spruce regeneration dynamics can be separated into distinct phases: (i) layering within the understory, (ii) seedling growth when gaps open in the canopy, (iii) gradual canopy closure, and (iv) production of new layers once the canopy is closed. These dynamics are not observed in paludified stands or stands where balsam fir is more competitive than black spruce. Overall, this research helps explain the complexity of old-growth forest dynamics, where many ecological factors interact at multiple temporal and spatial scales. This study also improves our understanding of ecological processes within primary old-growth forests and identifies the key factors to consider when ensuring the sustainable management of old-growth boreal stands.

Published in

PLoS ONE
2020, volume: 15, number: 7, article number: e0230221
Publisher: PUBLIC LIBRARY SCIENCE

Authors' information

Martin, Maxence
Univ Quebec Chicoutimi
Montoro Girona, Miguel
Swedish University of Agricultural Sciences, Department of Wildlife, Fish and Environmental Studies
Montoro Girona, Miguel
University of Quebec Montreal (UQAM)
Montoro Girona, Miguel
Université du Québec en Abitibi-Témiscamingue (UQAT)
Morin, Hubert
Univ Quebec Montreal

Associated SLU-program

SLU Network Plant Protection

Sustainable Development Goals

SDG15 Life on land

UKÄ Subject classification

Forest Science

Publication Identifiers

DOI: https://doi.org/10.1371/journal.pone.0230221

URI (permanent link to this page)

https://res.slu.se/id/publ/107246