Ten-year Growth Response of Black Spruce to Thinning and Fertilization Treatments

1975 ◽  
Vol 5 (2) ◽  
pp. 302-309 ◽  
Author(s):  
G. F. Weetman

A 65-year-old upland black spruce (Piceamariana Mill. B.S.P.) stand near Baie Comeau, Quebec, was thinned and fertilized with urea; each treatment was at 2 levels in a split plot factorial design. The trees responded to the nitrogen addition after 1 year and to thinning after 7 years. The trees were still growing faster in response to most treatments after 10 years. Trees of all size classes responded to the treatments. The periodic increment was not increased by 25% thinning, but was increased by 50% thinning and was always increased by nitrogen additions. Absolute increases over control values ranged from 130 to 290 ft3 (11 to 24.6 m3) for an application of 100 lb N per acre (112 kg N per hectare) and 238 to 297 ft3 (20 to 25.2 m3) for 400 lb N per acre (444 kg N per hectare) (1 ha = 104 m2). Some synergistic effect of combined thinning and fertilizer treatments is indicated.Mortality losses in the 10-year period were appreciable because of excessive stand density. The roles of thinning and fertilizer treatments in black spruce management are discussed.

2016 ◽  
Vol 38 (3) ◽  
Author(s):  
JULIANA DOMINGUES LIMA ◽  
JÉSSICA SANTA ROSA ◽  
DANILO EDUARDO ROZANE ◽  
EDUARDO NARDINI GOMES ◽  
SILVIA HELENA MODENESE GORLA DA SILVA

ABSTRACT Plant growth regulators can influence fruit yield and quality. This study aimed to evaluate the effect of cytokinin and gibberelin on the agronomic and physicochemical characteristics of banana fruits cv. ‘Prata’ (Musa spp. AAB), according to the formation period and position in the bunch. The experiment was conducted in a completely randomized 2 x 5 factorial design, two periods of bunch development (summer and winter), five treatments and ten replicates. To study the effect of position in the bunch, split plot was adopted, considering in the plot, 2 x 5 factorial and in subplots, hand 1, hand 4 and last hand. Treatments consisted of 2 pulverizations with water, 150 mg L-1 cytokinin, 200 mg L-1 of gibberellic acid, 100 mg L-1 of cytokinin plus 200 mg L-1 of gibberellic acid and 200 mg L-1 of cytokinin plus 200 mg L-1 of gibberellic acid, applied from the fourth to the last hand of the bunch. Cytokinin and gibberellin, alone or associated, regardless of formation period and position, did not affect the size and physicochemical characteristics of fruits, only delayed the bunch harvest.


1996 ◽  
Vol 13 (2) ◽  
pp. 68-72 ◽  
Author(s):  
Joanie Burns ◽  
Klaus J. Puettmann ◽  
Don Perala

Abstract Two different thinning methods were applied to three 6- or 7-yr-old black spruce stands in northern Minnesota which were measured after 20 yr. Overall, thinning improved the growing conditions for crop trees. Strip thinning with a 0.6 m leave strip and three widths of cleared strips (1.5 m, 2.1 m, and 2.7 m), and spacing to 1.5 m, 2.1 m, and 2.7 m resulted in reduced numbers of crop trees, but with larger diameters and, in the spacing thinned plots, greater heights. Because of these contradicting trends, stand volume was unaffected by thinning. Crop tree growth was not affected by the width of the cleared strip, but the distances between the leave trees in the square spacing were positively related to the increased growth response after thinning. The study is still too young to evaluate the economic feasibility of both thinning treatments, but shorter rotations or substantially increased volume seem possible by early thinnings of black spruce. North. J. Appl. For. 13(2):68-72.


1994 ◽  
Vol 70 (1) ◽  
pp. 65-74 ◽  
Author(s):  
P. F. Newton ◽  
G. F. Weetman

A stand density management diagram for managed black spruce (Picea mariana (Mill.) B.S.P.) stands was developed using data derived from 37 variable-size temporary and permanent sample plots, and 257 open-grown sample trees. The plots were situated within 15 plantations and 4 precommercially thinned stands located throughout central and western Newfoundland, north-western New Brunswick and northern Ontario. The basic components of the diagram included: (1) an approximate crown closure line (2) the self-thinning rule (3) expected size-density trajectories and (4) isolines for dominant height, relative density index, quadratic mean diameter and merchantability ratio. The utility of the diagram was demonstrated by deriving yields for various initial spacings by site class and subsequently evaluating various outcomes in terms of operability criteria. In addition, the potential of estimating the time of crown closure by initial spacing and site class is discussed in relation to minimizing the adverse effects of Kalmia angustifolia (L.) on black spruce growth and development. Key words: stand density management diagram, initial spacing, black spruce, operability, Kalmia angustifolia (L.)


1998 ◽  
Vol 74 (1) ◽  
pp. 106-115 ◽  
Author(s):  
Brian E. McLaren ◽  
John K. Jeglum

We report tenth-year growth and yield improvements in the Wally Creek area, an experimental, systematic drainage project established in 1984 and fertilized in 1986, in a forested Ontario peatland. We analyzed and compared results for dominant–codominant and intermediate black spruce in two site types. Response of trees to NPK-fertilization was more immediate than to drainage. Response to drainage took about five to seven years, whereas response to fertilization occurred earlier, from three to five years. Some indication of an asymmetric response, with larger trees experiencing higher growth increases, was observed for the OG 11 (Ledum) site type, while yield increases were potentially higher in the OG 12 (Alnus herb-poor) site type. Drainage was most effective in combination with fertilization. Consistent for both site types were increases in phosphorus associated with fertilization. The Wally Creek project is a benchmark in the analysis of growth and yield response from intensive peatland silviculture. Key words: black spruce, drainage, fertilization, foliar analysis, growth response, growth and yield, Lake Abitibi Model Forest, Ontario, stem analysis


2007 ◽  
Vol 37 (9) ◽  
pp. 1563-1571 ◽  
Author(s):  
H. C. Thorpe ◽  
S. C. Thomas ◽  
J. P. Caspersen

Variants of partial harvesting are gaining favour as means to balance ecosystem management and timber production objectives on managed boreal forest landscapes. Understanding how residual trees respond to these alternative silvicultural treatments is a critical step towards evaluating their potential from either a conservation or a wood supply perspective. We used dendroecological techniques combined with a chronosequence approach to quantify the temporal radial growth response pattern of residual black spruce ( Picea mariana (Mill.) BSP) trees to partial harvest in northeastern Ontario. At its peak, 8–9 years after harvest, radial growth of residual trees had doubled. The growth pattern was characterized by a 2-year phase of no response, a subsequent period of increase 3–9 years after harvest, and a stage of declining rates 10–12 years after harvest. The magnitude of tree growth response depended strongly on tree age: peak postharvest growth was substantially higher for young trees, while old trees displayed only modest growth increases. Both the large magnitude and the time delay in postharvest growth responses have important implications for the development of more accurate quantitative tools to project future yields and, more generally, for determining whether partial harvesting is a viable management option for the boreal forest.


2017 ◽  
Author(s):  
Carole Bastianelli ◽  
Adam A. Ali ◽  
Julien Beguin ◽  
Yves Bergeron ◽  
Pierre Grondin ◽  
...  

Abstract. At the northernmost extent of the managed forest in Quebec, the boreal forest is currently undergoing an ecological transition between two forest ecosystems. Open lichen woodlands (LW) are spreading southward at the expense of more productive closed-canopy black spruce-moss forests (MF). The objective of this study was to investigate whether soil properties could distinguish MF from LW in the transition zone where both ecosystem types coexist. All the soils studied were typical podzolic soil profiles evolved from glacial till deposits that shared a similar texture of the C layer. However, soil humus and the B layer varied in thickness and chemistry between the two forest ecosystems at the pedon scale. Multivariate analyses of variance were used to evaluate how soil properties could help distinguish the two types at the site scale. MF humus (FH horizons) showed significantly higher concentrations of organic carbon and of the main exchangeable base cations (Ca, Mg) than LW soils, which were nutritionally poorer. The B horizon of LW sites held higher concentrations of total Al and Fe oxides, and particularly greater concentrations of inorganic amorphous Fe oxides than MF mineral soils, while showing a thinner B layer. Overall, our results show that MF store three times more organic carbon in their soils (B + FH horizons, roots apart) than LW. We suggest that variations in soil properties between MF and LW are linked to a cascade of events involving the impacts of natural disturbances such as wildfires on forest regeneration that determines the of vegetation structure (stand density) and composition (ground cover type) and their subsequent consequences on soil environmental parameters (moisture, radiation rate, redox conditions, etc.). Our data underline significant differences in soil biogeochemistry under different forest ecosystems and reveal the importance of interactions in the soil–vegetation–climate system for the determination of soil composition.


Sign in / Sign up

Export Citation Format

Share Document