Impacts of mechanical site preparation on foliar nutrients of planted white spruce seedlings on mixed-wood boreal forest sites in Alberta

1998 ◽  
Vol 110 (1-3) ◽  
pp. 35-48 ◽  
Author(s):  
S. Ellen Macdonald ◽  
Margaret G. Schmidt ◽  
Richard L. Rothwell
Keyword(s):  
Boreal Forest ◽  
White Spruce ◽  
Site Preparation ◽  
Foliar Nutrients ◽  
Mechanical Site Preparation ◽  
Forest Sites

Impacts of harvesting and mechanical site preparation on soil chemical properties of mixed-wood boreal forest sites in Alberta

1996 ◽  
Vol 76 (4) ◽  
pp. 531-540 ◽  
Author(s):  
M. G. Schmidt ◽  
S. E. Macdonald ◽  
R. L. Rothwell
Keyword(s):  
Boreal Forest ◽  
Mineral Soil ◽  
Chemical Properties ◽  
Site Preparation ◽  
Available Phosphorus ◽  
Organic Layer ◽  
Mechanical Site Preparation ◽  
Forest Sites ◽  
Mineralizable Nitrogen ◽  
Surface Mineral

We examined the impacts of harvesting and mechanical site preparation (MSP) on soil chemical properties of mixed-wood boreal forest sites in west central Alberta. Treatments included: 1) disc trencher, hinge, and trench microsites; 2) ripper plow, hinge, and trench microsites; 3) blading thin (organic layer depth < 2 cm), and thick (organic layer depth > 2 cm) microsites; 4) harvested with no site preparation; and 5) unharvested. Twenty months after harvesting, the forest floor of harvested areas with no MSP (vs. unharvested) had higher carbon:nitrogen ratios lower pH, and lower concentrations of total and mineralizable nitrogen, available phosphorus, and exchangeable bases Fifteen months after MSP, treated areas had either reduced or unchanged concentrations of total nitrogen and carbon, available phosphorus, and mineralizable nitrogen in the surface mineral soil, compared with harvested sites with no site preparation. The MSP-treated areas also had increased or unchanged pH, base saturation, and exchangeable base concentrations. Microsites adjacent to the displaced forest floor (hinge for disc and ripper treatments) or with a thicker organic layer (thick for blading) generally had higher concentrations of total nitrogen and carbon, and mineralizable nitrogen in the surface mineral soil as compared to trench and thin microsites. Key words: Forest soils, mechanical site preparation, harvesting, N, P, mixed-wood boreal forest

Summary and Synthesis: Past and Future Changes in the Alaskan Boreal Forest

2006 ◽  
Author(s):  
Marilyn W. Walker ◽  
Mary E. Edwards
Keyword(s):  
Boreal Forest ◽  
Bark Beetles ◽  
Fire Regime ◽  
Black Spruce ◽  
Rapid Change ◽  
White Spruce ◽  
Late Glacial ◽  
Fire Frequency ◽  
Tree Resistance ◽  
Forest Sites

Historically the boreal forest has experienced major changes, and it remains a highly dynamic biome today. During cold phases of Quaternary climate cycles, forests were virtually absent from Alaska, and since the postglacial re-establishment of forests ca 13,000 years ago, there have been periods of both relative stability and rapid change (Chapter 5). Today, the Alaskan boreal forest appears to be on the brink of further significant change in composition and function triggered by recent changes that include climatic warming (Chapter 4). In this chapter, we summarize the major conclusions from earlier chapters as a basis for anticipating future trends. Alaska warmed rapidly at the end of the last glacial period, ca 15,000–13,000 years ago. Broadly speaking, climate was warmest and driest in the late glacial and early Holocene; subsequently, moisture increased, and the climate gradually cooled. These changes were associated with shifts in vegetation dominance from deciduous woodland and shrubland to white spruce and then to black spruce. The establishment of stands of fire-prone black spruce over large areas of the boreal forest 5000–6000 years ago is linked to an apparent increase in fire frequency, despite the climatic trend to cooler and moister conditions. This suggests that long-term features of the Holocene fire regime are more strongly driven by vegetation characteristics than directly by climate (Chapter 5). White spruce forests show decreased growth in response to recent warming, because warming-induced drought stress is more limiting to growth than is temperature per se (Chapters 5, 11). If these environmental controls persist, projections suggest that continued climate warming will lead to zero net annual growth and perhaps the movement of white spruce to cooler upland forest sites before the end of the twenty-first century. At the southern limit of the Alaskan boreal forest, spruce bark beetle outbreaks have decimated extensive areas of spruce forest, because warmer temperatures have reduced tree resistance to bark beetles and shortened the life cycle of the beetle from two years to one, shifting the tree-beetle interaction in favor of the insect (Chapter 9).

scholarly journals Caribou Conservation: Restoring Trees on Seismic Lines in Alberta, Canada

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 185 ◽  
Author(s):  
Angelo Filicetti ◽  
Michael Cody ◽  
Scott Nielsen
Keyword(s):  
Boreal Forest ◽  
Rangifer Tarandus ◽  
Site Preparation ◽  
Tree Regeneration ◽  
Tree Density ◽  
Petroleum Exploration ◽  
Rangifer Tarandus Caribou ◽  
Mechanical Site Preparation ◽  
Undisturbed Forest ◽  
Seismic Lines

Seismic lines are narrow linear (~3–8 m wide) forest clearings that are used for petroleum exploration in Alberta’s boreal forest. Many seismic lines have experienced poor tree regeneration since initial disturbance, with most failures occurring in treed peatlands that are used by the threatened woodland caribou (Rangifer tarandus caribou). Extensive networks of seismic lines, which often reach densities of 40 km/km2, are thought to have contributed to declines in caribou. The reforestation of seismic lines is therefore a focus of conservation. Methods to reforest seismic lines are expensive (averaging $12,500 per km) with uncertainty of which seismic lines need which treatments, if any, resulting in inefficiencies in restoration actions. Here, we monitored the effectiveness of treatments on seismic lines as compared to untreated seismic lines and adjacent undisturbed reference stands for treed peatlands in northeast Alberta, Canada. Mechanical site preparation (mounding and ripping) increased tree density when compared to untreated lines, despite averaging 3.8-years since treatment (vs. 22 years since disturbance for untreated). Specifically, treated lines had, on average, 12,290 regenerating tree stems/ha, which is 1.6-times more than untreated lines (7680 stems/ha) and 1.5-times more than the adjacent undisturbed forest (8240 stems/ha). Using only mechanical site preparation, treated seismic lines consistently have more regenerating trees across all four ecosites, although the higher amounts of stems that were observed on treated poor fens are not significant when compared to untreated or adjacent undisturbed reference stands.

White spruce establishment in boreal Ontario mixedwood: 5-year results

1995 ◽  
Vol 71 (5) ◽  
pp. 633-638 ◽  
Author(s):  
R. F. Sutton ◽  
T. P. Weldon
Keyword(s):  
Picea Glauca ◽  
Relative Effectiveness ◽  
Survival Rates ◽  
Growing Season ◽  
White Spruce ◽  
Site Preparation ◽  
Mechanical Site Preparation ◽  
Growing Seasons ◽  
Silvicultural Treatments ◽  
Block Experiment

Five-year results of a study to evaluate the relative effectiveness of nine silvicultural treatments for establishing plantations of white spruce (Picea glauca [Moench] Voss) in boreal Ontario mixed-wood are presented. The experimental design provided three levels of mechanical site preparation (none, disk trenching, and toothed-blading) in all combinations with three kinds of chemical weed control (none, Velpar L© at the time of planting, and Vision© during the second growing season). A randomized block experiment using 0.8-ha plots and two replications was established in Oates Twp. in 1985 and repeated in adjacent Oswald Twp. in 1986. Bareroot white spruce was planted throughout. Four 25-tree sub-plots, located systematically from a random start, were established in each plot. White spruce performance was monitored for five years. Fifth-year survival rates averaged 34% and 84% without and with mechanical site preparation, respectively. Mean total heights after five growing seasons differed significantly (P < 0.01) by category of mechanical site preparation: teeth > trencher > none. Other criteria of performance showed the same pattern. Because of operational exigencies, the herbicide treatments were not applied as scheduled, which might account for the apparent ineffectiveness of those treatments in the particular circumstances of this study. Key words: Site preparation, disk trencher, Young's teeth, herbicides

scholarly journals Alternatives to broadcast burning in the northern interior of British Columbia: Short-term tree results

2000 ◽  
Vol 76 (2) ◽  
pp. 349-353 ◽  
Author(s):  
J. M. Kranabetter ◽  
D. Yole
Keyword(s):  
British Columbia ◽  
Pinus Contorta ◽  
High Elevation ◽  
Site Preparation ◽  
Foliar Nutrients ◽  
Short Term ◽  
Positive Role ◽  
North Central ◽  
Mechanical Site Preparation ◽  
Foliar Concentrations

We compared the growth and foliar nutrients of lodgepole pine and hybrid white spruce following mechanical site preparation treatments and broadcast burning in a high-elevation plantation in north-central British Columbia. After five years, the largest trees were found on the broadcast burn (44% increase over raw planting), followed by disc-trenching (26% increase), and then windrow piling (9% increase). Height increment was similarly significantly different between treatments after seven years. Equal increases in nitrogen, phosphorus, and sulphur foliar concentrations were found across all site preparation treatments compared to controls. Foliar nutrients alone, however, did not further explain the differences in tree productivity between site preparation treatments. The results demonstrated how some sites can benefit from site preparation, in the short-term at least, and also emphasized the positive role fire can have on forest productivity. Key words: mechanical site preparation, broadcast burning, Picea gluaca, Pinus contorta

The effect of mechanical site preparation on ectomycorrhizae of planted white spruce seedlings in conifer-dominated boreal mixedwood forest

2008 ◽  
Vol 38 (7) ◽  
pp. 2072-2079 ◽  
Author(s):  
Lance W. Lazaruk ◽  
S. Ellen Macdonald ◽  
Gavin Kernaghan
Keyword(s):  
Picea Glauca ◽  
Untreated Control ◽  
White Spruce ◽  
Site Preparation ◽  
Organic Layer ◽  
Root Tips ◽  
Mechanical Site Preparation ◽  
Clear Cut ◽  
Mixed Treatment ◽  
Boreal Mixedwood Forest

We characterized the ectomycorrhizae (ECM) of planted white spruce ( Picea glauca (Moench) Voss) seedlings as affected by mechanical site preparation (MSP) of clear-cut conifer-dominated boreal mixedwood forest. Relative abundance, richness, and composition of the ECM community were compared among untreated control, mixed, mounded, and scalped site preparation treatments. On >11 000 root tips, we observed 16 ECM morphotypes. Those common to the nursery in which the seedlings were raised were most abundant ( Thelephora americana , Wilcoxina -like (E-strain), Amphinema byssoides , Phialocephala -like (MRA)). Seedlings in the untreated controls had lower abundances of these, but higher abundances of other ECM, which were not present in the nursery of origin but were indigenous to these forest stands. In terms of ECM composition, the “mixed” treatment was most similar to the untreated control, while the “scalped” and “mound” treatments showed significantly different ECM communities than the controls. Our results suggest that MSP may facilitate continued dominance by ECM that establish on seedlings in the nursery while slowing the natural succession towards the natural forest ECM. MSP treatments that leave some surface organic matter relatively intact may impact ECM less than those that remove or bury the organic layer.

Leaching of cations and sulphate after mechanical site preparation at a boreal forest clear-cut area

Geoderma ◽  
2009 ◽  
Vol 149 (3-4) ◽  
pp. 386-392 ◽  
Author(s):  
Sirpa Piirainen ◽  
Leena Finér ◽  
Hannu Mannerkoski ◽  
Michael Starr
Keyword(s):  
Boreal Forest ◽  
Site Preparation ◽  
Mechanical Site Preparation ◽  
Clear Cut

scholarly journals White spruce establishment in two boreal Ontario mixedwoods: 13-year results

2003 ◽  
Vol 79 (1) ◽  
pp. 127-131
Author(s):  
R F Sutton ◽  
T P Weldon
Keyword(s):  
Picea Glauca ◽  
Untreated Control ◽  
Growing Season ◽  
White Spruce ◽  
Site Preparation ◽  
Mechanical Site Preparation ◽  
Treatment Performance ◽  
Growing Seasons ◽  
Control Growth ◽  
Herbicide Treatments

An experiment to investigate techniques for establishing white spruce (Picea glauca [Moench] Voss) in boreal Ontario mixedwood was begun in 1985 in Oates Twp. Eight 25-tree plots were established in each of nine treatments: three mechanical site preparation treatments (none, disk- trenching, and toothed-blading) in combination with three kinds of chemical weed control (none, Velpar L® at the time of planting, and Vision® during the second growing season). The experiment was repeated the following year in the adjacent township of Oswald. The mechanical treatments were applied as planned, but the herbicide treatments deviated somewhat from the plan. Fifth-year results were reported in this journal in 1995. In the eighth growing season, a ground-spray release treatment with Vision® was applied to four randomly selected 25-tree plots in each original treatment. Performance of white spruce after 13 growing seasons was significantly influenced by site preparation: survival averaged 65 and 79% without release in the blading and trenching treatments, respectively, and 22% in the untreated control; with release, survival averaged 74 and 80% in the blading and trenching treatments, respectively, and 24% in the untreated control. Growth was greatest in the bladed treatment, poorest by far in the untreated control. The ineffectiveness of herbicides in these experiments is surprising in view of successes elsewhere. The modest response to release was significant for 13th -year increment. Key words: site preparation, toothed blading, trenching, release

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