Growth of tree species and hydrology in managed forested peatlands, Quebec

Jutras, Sylvain
Philosophiæ doctor (Ph.D.)
Université Laval
Doctorat en sciences forestières

Directeur(trice) de recherche : Bégin, Jean

Co directeur(trice) de recherche : Hokka, Hannu Kalevi

2006-05

Dédicace

À mes parents, je voudrais une fois de plus exprimer ma gratitude pour leur support inconditionnel.

Geneviève, mon amour, ton dévouement pour moi et pour notre petite famille n’est pas passé inaperçu. Je suis un homme heureux. Je t’aime.

Table des matières

General introduction
- References
CHAPTER 1 Draining an unproductive black spruce peatland stand: 18-year post-treatment tree growth assessment and future stand productivity estimation
CHAPTER 2 Water-table rise after harvesting in a treed fen previously drained for forestry
CHAPTER 3 Water table changes following precommercial thinning on post-harvest drained wetlands
CHAPTER 4 Beneficial influence of plant neighbours on tree growth in drained forested peatlands – A case study
CHAPTER 5 Influence of intra- and inter-specific competition on black spruce growth in post-harvest drained forested peatlands
General conclusion

Liste des illustrations

Figure 1. Map of the drained unproductive black spruce peatland stand, showing the numbered experimental plot locations. Aerial photography #Q98509-149, June 1998. © Gouvernement du Québec
Figure 2. Initial black spruce dimensions as a tree growth factor on a drained unproductive peatland stand. Values were estimated for a fixed distance to the center of the ditch (mean distance = 11.68 m).
Figure 3. Effects of ditch proximity on black spruce growth in a drained unproductive peatland stand. Values were estimated for a fixed diameter at drainage (Mean diameter = 2.48 cm).
Figure 4. Site productivity estimation for a drained unproductive black spruce peatland stand over an 80-year post-drainage period. Classes of distance to the center of the closest ditch (0-10 m, 10-20 m, 20-30 m) and the reference ditch (UP or DOWN) were used to classify the observations. Actual SI values were measured at year 0 and 18, while they were predicted for year 30 and beyond.
Figure 1: Drainage and sampling design on treated site.
Figure 2: Calibration curve of the water-table depth for the treated site without drainage effect and the water-table of the control site. Treated water-table from 1986 was collected before drainage. From 1987 to 1989, it was collected after drainage in the 60 m spacing, from the well located at 30 m from the closest ditch.
Figure 3: Predicted water-table depth (PWT) following drainage and timber harvesting of a forested peatland site in function of ditch spacing, distance to the closest ditch, period of observation and predicted water-table depth if no treatment was applied (PWTno).
Figure 1: Details of the experimental design of a hypothetical study site.
Figure 2: Daily precipitation and mean water table depth to the soil level for the control wells (diamonds, thin line) and the thinned wells (+, hatched line), before (2003) and after (2004-2005) precommercial thinning (all sites included).
Figure 3: Example of the regression between treated and control wells for the calibration period (2003) and the post-treatment values for 2004 and 2005 (Site I, Row 3, DIST = 20 m).
Figure 4: Least square means and error bars (± 2SE) of the water table rise (WTR) in function of the year of measurement and the soil type.
Figure 5: Predicted mean values of the water table rise (WTR) as a function of the basal area removal (TYPE = Mineral, DIST = 7 m, YEAR = 2004 and general mean values for the other covariates).
Figure 6: Predicted mean values of the water table rise (WTR) as a function of the predicted water table depth (TYPE = Mineral, DIST = 7 m, YEAR = 2004 and general mean values for the other covariates).
Figure 7: Predicted mean values of the water table rise (WTR) as a function of the observation day (TYPE = Mineral, DIST = 7 m, YEAR = 2004 and general mean values for the other covariates).
Figure 1: Annual stump diameter increment (ΔD_0.3) for eastern larch, 5, 10 and 15 years after plantation (TIME) as a function of distance to the closest ditch (NEAR: 1 to 6 m; FAR: 6 to 16 m) and neighbourhood occupancy (G_<3m). Mean values at each predicted TIME period were used for the other explanatory variables.
Figure 2: Annual stump diameter increment (ΔD_0.3) for black spruce, 5, 10 and 15 years after plantation (TIME) as a function of distance to the closest ditch (NEAR: 1 to 6 m; FAR: 6 to 16 m) and neighbourhood occupancy (G_<3m). Mean values at each predicted TIME period were used for the other explanatory variables.
Figure 3: Mean annual stump diameter increment (ΔD_0.3) of eastern larch and black spruce in function of the presence or absence of speckled alder in a 3 m radius from the subject tree. Different letters indicates significant differences between classes of the same species.
Figure 1: Annual diameter (A) and height (B) increments of naturally regenerated black spruce seedlings in post-harvest drained, forested peatlands as a function of the initial dimensions and the operational group (OG). Other variables have been fixed at specific values: DIST = 5 to 10 m, LI = M-Mixed, and ALDER = 0.
Figure 2: Annual diameter (A) and height (B) increments of naturally regenerated black spruce seedlings in post-harvest drained forested peatlands in function of the distance to the ditch (DIST). Different letters indicate significant differences at the 5 % level.
Figure 3: Annual diameter (A) and height (B) annual increments of naturally regenerated black spruce seedlings in post-harvest drained, forested peatlands as a function of light interception (LI). Different letters indicate significant differences at the 5 % level between LI classes of the same type. The 0 % LI class was repeated (hatched bars) for every type of LI to facilitate class comparisons. L = 5-30 % of total intercepted light; M = 35-60 % and H = >60 %.

Liste des tableaux

Table 1: Black spruce diameters at stump height (DSH), stem heights (H) and ages at stand drainage (1984) and 18 years after drainage (2002), together with mean pre- and post-drainage annual diameter increments.
Table 2: Analysis of covariance (ANCOVA) of the 18-year post-drainage mean annual stump diameter increment (ln(ADI84-02)).
Table 1: Site characteristics before drainage.
Table 1: Description of the six selected sites
Table 2: Analysis of covariance of the water table rise (WTR) after precommercial thinning (PCT).
Table 1: Attributes of the plots and the eastern larch and black spruce trees.
Table 2: Estimates, standard errors (SE) and p value of the fixed parameters and the variance components of the annual stump diameter increment models.
Table 1: Ecological descriptions of the study sites (OG adapted from Jones et al. 1983)
Table 2: Frequency tables of alder-willow in the permanent regeneration plots located in recently harvested and drained peatlands. Percentage appears in parenthesis .
Table 3: Frequency tables of aspen-birch in the permanent regeneration plots located in recently harvested and drained peatlands. Percentage appears in parenthesis
Table 4: Frequency tables of black spruce in the permanent regeneration plots located in recently harvested and drained peatlands. Percentage appears in parenthesis
Table 5: Logistic regression summaries on the occurrence of the principal black spruce’s competitive tree species in the permanent regeneration plots located in recently harvested and drained peatlands.
Table 6: Summary of the variance analysis on ln-transformed last annual diameter (ln(DI)) and height increment (ln(HI)) of black spruce seedlings located on drained peatland sites.


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