Fig 1.
Map of the study territory showing the location of the sample sites (red filled circles).
The insert map indicates the location of the study territory in the province of Quebec, Canada (red dot). The cartographic data used to generate this comes from freely available maps map (“Carte écoforestière du troisième inventaire” and “Classification écologique du territoire québécois”), published by the Government of Quebec (https://www.donneesquebec.ca/fr/). This map was produced with the ArcGIS Desktop software, version 10.7.1.
Fig 2.
Schematic representation of the experimental design used for the sample sites.
N: north; CWD: coarse woody debris.
Table 1.
Description of the regeneration, stand structure, and abiotic attributes measured at the study sites, adapted from Martin et al. [40].
Fig 3.
(A) Density of black spruce seedlings and saplings at the 71 studied sites, grouped by black spruce regeneration clusters. (B) Value of the SSI criterion according to the number of clusters for black spruce, using k-means clustering. Filled circle in (B) indicates the highest value of the SSI criterion.
Table 2.
Mean and standard deviation of the regeneration attributes for (A) black spruce regeneration clusters and (B) balsam fir regeneration clusters.
Fig 4.
(A) Density of balsam fir seedlings and saplings at the 48 studied sites of the balsam fir regeneration portion of the study, grouped by balsam fir regeneration clusters. (B) Value of the SSI criterion according to the number of clusters for balsam fir, using k-means clustering. Filled red circles in (B) indicate the highest value of the SSI criterion.
Fig 5.
Density of black spruce seedlings and saplings at the 71 studied sites.
The colors represent the gradients of values for the significant structural and environmental attributes, as determined by Spearman correlation tests.
Fig 6.
Density of balsam fir seedlings and saplings at the 48 studied sites of the balsam fir regeneration portion of the study.
The colors represent the gradients of values for the various significant structural and environmental attributes, as determined by Spearman correlation tests.
Table 3.
Spearman correlation coefficients between regeneration attributes and structural and environmental attributes.
Table 4.
Mean values and 95% confidence intervals (C.I.) of the partitioned R2 and total variance explained, of the bootstrapped regression models for the various regeneration attributes.
Table 5.
Mean and standard deviation of the structural and environmental attributes for black spruce regeneration clusters (BS).
Table 6.
Mean ± standard deviation of structural and environmental attributes for balsam fir regeneration clusters (BF).
Fig 7.
Dynamics of (A) black spruce and (B) balsam fir regeneration based on secondary disturbance regime and topography as derived from the identified regeneration clusters. Water paintings published under a CC BY license, with permission from Valentina Buttò, original copyright 2019.