Forest floor mass and nutrients in two chronosequences of plantations: Jack pine vs. black spruce

1998 ◽  
Vol 78 (1) ◽  
pp. 77-83 ◽  
Author(s):  
Helmut Krause

The purpose of this study was to determine whether change of forest cover had an effect on the development of the organic surface horizons, particularly on those variables that influence nutrient cycling and forest productivity. Jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana [Mill.] B.S.P.) plantations were selected from among the youngest to oldest (2–16 yr) within a 100 km2 area in southeastern New Brunswick. Natural forests were also included as benchmark sites. The forest floor and tree foliage was sampled and trees measured on 0.05-ha plots. The forest floor samples were used to determine organic mass, nutrient contents and pH. In pine plantations, organic matter accumulated rapidly during the period of exponential tree growth, but leveled off at about 45 Mg ha–1. This was within the range of benchmark sites with mixed conifer-hardwood cover. In spruce plantations, the forest floor mass ranged upward to 77 Mg ha–1. Development was strongly influenced by the nature of the previous forest. Spruce forest floors were on average more acid and had lower nutrient concentrations, particularly N and Ca. The observed differences suggest that nutrients are recycled more rapidly in the pine plantations, partly explaining the superior growth of the latter. Key words: Forest floor, Kalmia angustifolia L., Picea mariana (Mill.) B.S.P., Pinus banksiana Lamb., nutrient cycling, plantation forest

2004 ◽  
Vol 34 (9) ◽  
pp. 1938-1945 ◽  
Author(s):  
Isobel Waters ◽  
Steven W Kembel ◽  
Jean-François Gingras ◽  
Jennifer M Shay

This study compares the effects of full-tree versus cut-to-length forest harvesting methods on tree regeneration in jack pine (Pinus banksiana Lamb.), mixedwood (Picea glauca (Moench) Voss – Populus tremuloides Michx. – Abies balsamea (L.) Mill.), and black spruce (Picea mariana (Mill.) BSP) sites in southeastern Manitoba, Canada. We surveyed tree regeneration densities, disturbance characteristics, and understorey vegetation in replicated control and harvested plots in each site type preharvest (1993) and 1 and 3 years postharvest (1994, 1996). In jack pine sites, the full-tree harvest method promoted regeneration of Pinus banksiana through increased disturbance of soil and the moss layer, and decreased slash deposition relative to the cut-to-length method. Conversely, in mixedwood sites the cut-to-length method resulted in less damage to advance regeneration and proved better at promoting postharvest regeneration of Abies balsamea and Picea glauca relative to the full-tree method. In black spruce sites, there were few differences in the impact of the two harvesting methods on regeneration of Picea mariana, which increased in frequency and density after both types of harvesting.


2009 ◽  
Vol 85 (1) ◽  
pp. 43-56 ◽  
Author(s):  
Xiangdong Lei ◽  
Changhui Peng ◽  
Haiyan Wang ◽  
Xiaolu Zhou

Historically, height–diameter models have mainly been developed for mature trees; consequently, few height–diameter models have been calibrated for young forest stands. In order to develop equations predicting the height of trees with small diameters, 46 individual height–diameter models were fitted and tested in young black spruce (Picea mariana) and jack pine (Pinus banksiana) plantations between the ages of 4 to 8 years, measured from 182 plots in New Brunswick, Canada. The models were divided into 2 groups: a diameter group and a second group applying both diameter and additional stand- or tree-level variables (composite models). There was little difference in predicting tree height among the former models (Group I) while the latter models (Group II) generally provided better prediction. Based on goodness of fit (R2and MSE), prediction ability (the bias and its associated prediction and tolerance intervals in absolute and relative terms), and ease of application, 2 Group II models were recommended for predicting individual tree heights within young black spruce and jack pine forest stands. Mean stand height was required for application of these models. The resultant tolerance intervals indicated that most errors (95%) associated with height predictions would be within the following limits (a 95% confidence level): [-0.54 m, 0.54 m] or [-14.7%, 15.9%] for black spruce and [-0.77 m, 0.77 m] or [-17.1%, 18.6%] for jack pine. The recommended models are statistically reliable for growth and yield applications, regeneration assessment and management planning. Key words: composite model, linear model, model calibration, model validation, prediction interval, tolerance interval


1975 ◽  
Vol 51 (2) ◽  
pp. 53-54
Author(s):  
W. Stanek

Black spruce (Picea mariana [Mill.] B.S.P.) and jack pine (Pinus banksiana Lamb.) seedlings were grown in a green-house on peat-filled flats flooded with nutrient solution or distilled water. None was aerated. However, an O2 concentration gradient existed across the flats, 3.0 – 3.7 ppm along the edges, and 1.4 – 1.9 ppm in the centers. After 4½ months seedlings of both species grew taller with nutrient solution than with distilled water. In flats supplied with nutrient solution, seedlings of both species grew taller along the edges than in the centers, whereas in flats supplied with distilled water height differential did not develop. Jack pine grew taller than black spruce under similar conditions.


1986 ◽  
Vol 62 (5) ◽  
pp. 446-450 ◽  
Author(s):  
S. W. J. Dominy ◽  
J. E. Wood

Seeding trials were established on four different sites in northern Ontario (46°41′N to 49°19′N) in 1979 and 1980. Jack pine (Pinus banksiana Lamb.) was seeded on two medium sand sites, black spruce (Picea mariana [Mill.] B.S.P.) on a sandy clay site, and white spruce (P. glauca [Moench] Voss) on a clay site. Conventional bare spot seeding was compared with spot seeding under Finnish-designed plastic shelters. At least two seeding dates were compared in each trial. Third- and fifth-year stocking and fifth-year height data are presented.Stocking of all three species was increased, regardless of sowing date, when shelters were used. With the exception of June-sown black spruce and one June sowing of jack pine, height growth was not significantly improved through the use of seed shelters. Shelters may prove to be a viable regeneration option only on cooler, exposed sites with little vegetative competition. Key words: Shelter spot seeding, bare spot seeding, Pinus banksiana Lamb., Picea mariana [Mill.] B.S.P., P. glauca [Moench] Voss.


2005 ◽  
Vol 35 (11) ◽  
pp. 2655-2663 ◽  
Author(s):  
Jean-Gabriel Elie ◽  
Jean-Claude Ruel

In this study we compare the mechanical resistance of black spruce (Picea mariana (Mill.) BSP) and jack pine (Pinus banksiana Lamb.) and quantify the effect of species, forest cover type, and soil conditions on tree stability. To measure tree resistance to an applied load, 85 trees were pulled over using a cable and winch system. Predictive equations for the maximum turning moment that a tree can withstand (Mc) were developed with stem mass, and the other factors were used as explanatory variables. The presence of jack pine within the stand negatively affected black spruce resistance. In mixed stands, Mc was significantly influenced by the interaction between tree species and soil type. Jack pine was the only species with significantly lower resistance when grown on shallow and stony soils, which are likely to restrict root development. Black spruce resistance was not affected by soil conditions. Preliminary calculations of critical wind speeds required to cause damage using an adaptation of the ForestGALES model were much lower than those previously published for black spruce.


2012 ◽  
Vol 42 (8) ◽  
pp. 1456-1466 ◽  
Author(s):  
Suzanne Brais ◽  
Pascal Drouin

Decaying wood contribution to the heterogeneity of forest soils could depend on tree species and wood decay stage. The study was conducted in an 85-year-old trembling aspen ( Populus tremuloides Michx.) – jack pine ( Pinus banksiana Lamb.) forest in northwestern Quebec, Canada. Trees, snags, logs, and forest floor originating from wood buried within the forest floor (lignic FF) and from fine litter (alignic FF) were inventoried in fifteen 400 m2 plots (nine jack pine and six trembling aspen). Chemical properties of alignic and lignic FF and logs were measured and relative nutrient availability in the mineral soil assessed under logs and under lignic and alignic FF using PRS probes. No significant differences between forest covers were found for the proportion of C and nutrients contained in deadwood (snags, logs, and lignic FF) relative to tree biomass plus necromass (deadwood plus alignic FF) content. Lignic FF was characterized by a higher C/N ratio and exchangeable acidity than alignic FF and its nutrient concentrations were between those of alignic FF and logs. Differences in wood characteristics may explain some of the differences in forest floor properties observed between trembling aspen and jack pine. Nutrient availability in the mineral soil was affected by the overlaying materials and could reflect differences in the dynamics of individual nutrients.


2010 ◽  
Vol 86 (2) ◽  
pp. 193-199 ◽  
Author(s):  
G. Geoff Wang ◽  
Kevin J Kemball

Two boreal mixedwood stands burned by the 1999 Black River wildfire in southeastern Manitoba, Canada were selected to study the effect of fire severity on early survival and growth of planted jack pine (Pinus banksiana), black spruce (Picea mariana) and white spruce (Picea glauca) seedlings. In each stand, three fire severity classes (scorched, lightly burned, and severely burned) were identified based on the degree of forest floor consumption. Fire severity was not a significant factor on mortality. No mortality difference was found among species, except for year 5 when jack pine had significantly higher mortality than both black spruce and white spruce. Jack pine and black spruce had their highest mortality in year 4, while white spruce had its highest mortality in year 1. Under natural competition, seedling growth increased with increasing fire severity. When competition was removed, fire severity did not affect seedling growth. Regardless of fire severity and competition, jack pine had better diameter and height growth than black spruce, which, in turn, grew slightly taller than white spruce. Planted seedlings faced less intense vegetation competition on severely burned plots compared to scorched or lightly burned plots. Regardless of fire severity and species, competition increased with time since planting. Our study results indicate that planting immediately after a wildfire is a viable option to establish conifer components on burned boreal mixedwood stands. Key words: fire severity, plantation, regeneration, Pinus banksiana, Picea mariana, Picea glauca


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