A 249‐yr chronosequence of forest plots from eight successive fires in the Eastern Canada boreal mixedwoods

Abstract

A combination of wildfires and defoliating insect outbreaks play an important role in the natural successional dynamics of North American boreal mixedwood forests, which, in the long term, change the post‐disturbance composition and structure of forest stands. After stand‐replacing disturbances (mainly wildfires), early successional hardwoods typically dominate the affected areas. Provided enough time following disturbances, the increasing recruitment of mid‐ to late‐successional softwoods as well as the mortality of hardwoods gradually change forest composition from hardwoods to admixtures of hardwood‐conifer species and conifer‐dominated stands in mid and late successional stages, respectively. Such mixedwoods are abundant across the southern Canadian boreal forest. In boreal Canada, mixedwoods are the most structurally heterogeneous forest ecosystems, are highly productive, and form an important source of timber supply. Here we present the EASTERN BOREAL MIXEDWOODS CANADA data set, which documents the changes in composition and structure of stands originating from eight different wildfires representing a chronosequence of 249 yr since fire in eastern Canada. This data set has been used in several different projects to study and model the influence of natural (e.g., insect outbreaks) and anthropogenic disturbances (e.g., harvesting) on the dynamics of post‐fire stands. The data set covers a high range of variability in stand composition and structure, explained by species establishment, dominance, and mixture. It thus constitutes a useful source of information to trace the dynamics of the main boreal tree species of eastern North America, from their establishment to their replacement at different spatial scales (e.g., from stand to landscape level). Please cite this data paper when the data are used in publications. We also request that researchers and teachers inform us of how they are using the data. We are open to collaborate in developing or co‐authoring relevant research projects based on this data set.

Seedling recruitment in response to stand composition, interannual climate variability, and soil disturbance in the boreal mixed woods of Canada

“…This study uses the LDRTF‐SEEDLINGS data set available and documented in Maleki et al. (2021). One 400‐m 2 (20 m × 20 m) plot was established in 1990 in each of eight stands with different times since fire (fires occurring in 1760, 1797, 1823, 1847, 1870, 1916, 1944, and 1964) (Figure 1).…”

“…Recurrent wildfires and defoliating insect outbreaks are the main natural disturbances of the study region, with episodes affecting thousands of hectares of forestlands. Eight major wildfires since 1760 and three spruce budworm outbreaks during the last century have been documented for the study area (Maleki et al, 2021). No spruce budworm outbreak occurred during the study period (2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018)) and the previous outbreak ended in 1987 (Morin et al, 1993).…”

Competitive interactions under current climate allow temperate tree species to grow and survive in boreal mixedwood forest

“…In this study, we retained 37 RESEF plots where temperate tree species coexisted with boreal tree species. We also added to the RESEF data 6 additional mapped 1‐ha plots located in the FERLD, which have been inventoried 5 times since 1991 (Maleki et al 2021). The full parameterization dataset for our growth model thus included 43 plots, 19 184 different trees, for a total of 72 964 DBH observations.…”

“…For our simulation experiment, we obtained initial conditions for the SORTIE simulations from plots in the FERLD territory where tree DBH was sampled in a 400 m 2 area (Maleki et al 2021). These plots were unharvested post‐fire stands and harvested stands representing different successional forest stages and tree compositions (Maleki et al 2021). Unharvested post‐fire stands included plots with the following years of last fire: 1760, 1797, 1823, 1870, 1916 and 1964 (Fig.…”