scholarly journals Performance of planted spruce and natural regeneration after pre- and post-harvest spraying with glyphosate and partial cutting on an Ontario (Canada) boreal mixedwood site

2013 ◽  
Vol 86 (4) ◽  
pp. 475-480 ◽  
Author(s):  
R. Man ◽  
J. A. Rice ◽  
G. B. MacDonald
2015 ◽  
Vol 91 (01) ◽  
pp. 52-59 ◽  
Author(s):  
Rongzhou Man ◽  
G. Blake MacDonald

The conventional plantation approach to regenerating jack pine (Pinus banksiana) after harvesting maximizes pine growth but may reduce wood quality. In this study we examined growth of planted jack pine and natural regeneration after herbicide spraying and partial cutting treatments on a boreal mixedwood site in northeastern Ontario. Treatments were pre-harvest aerial spray, post-harvest ground spray in strips (partial spray), partial cut, and post-harvest aerial broadcast spray; an untreated reference stand was used for comparison. Pre-harvest spray was as effective as partial cutting and post-harvest broadcast spray in suppressing trembling aspen regeneration and providing adequate light for survival and growth of planted jack pine. Ten years after planting, mortality and growth of pines in the pre-harvest treatment were comparable to those in the partial and broadcast spray treatments. Due to vigorous growth of broadleaf species [mostly red maple; (Acer rubrum)], and shade from the residual overstory, jack pine was smallest in the partial cut treatment; however, based on branch size, branch-free stem length and stem taper, wood quality was highest in this treatment. Considering factors important to forest managers such as growth and quality of planted jack pine, treatment costs, and proportion of the harvested blocks allocated to conifer production, the preferred treatment was pre-harvest spray.


2013 ◽  
Vol 89 (04) ◽  
pp. 512-524 ◽  
Author(s):  
Martin Béland ◽  
Bruno Chicoine

We examined applicability of various partial cutting systems in order to regenerate tolerant hardwood stands dominated by sugar maple (Acer saccarhum), American beech (Fagus grandifolia) and yellow birch (Betula alleghaniensis) on northern New Brunswick J.D. Irving Ltd. freehold land. Sampling of 1065 one-m2 plots in 31 stands managed by selection cutting, shelterwood method and strip or patch cutting and in six control stands allowed a 15-year retrospective study of natural regeneration in stands of low residual densities and with minimal soil disturbance and no control of competing vegetation. Beech regeneration was most abundant in the patch cuts, yellow birch in shelterwood stands and sugar maple in the selection system areas. Results suggest that initial stand conditions influence the composition of the regeneration more than the prescribed treatment. At the stand scale (a few hectares), sugar maple recruitment was positively influenced by its proportion in the initial stand, and negatively by the cover of herbs and shrubs. Yellow birch regeneration was mainly affected by shrub competition. At the plot (1 m2) scale, mineral soil and decayed wood substrates and ground-level transmitted light were determinant factors for yellow birch regeneration. Beech-dominated stands were likely to regenerate to beech. A dense beech sucker understory was promoted in harvested patches. Areas with dense understory of American beech, shrubs, or herbs require site preparation to reduce interference either before or at the time of partial cutting. Shelterwood seed cutting and selection cutting should leave a residual of 12 m2/ha and 17 m2/ha respectively in seed trees uniformly distributed.


2006 ◽  
Vol 23 (3) ◽  
pp. 192-196 ◽  
Author(s):  
Amanda Farrar ◽  
William D. Ostrofsky

Abstract Root sprouting following harvesting of American beech has resulted in the development of dense, slow-growing thickets in many stands throughout Maine and the northeastern United States. The problem is compounded by the presence of beech bark disease, as most sprouts arise from roots of disease-susceptible genotypes. Ten-year post-harvest regeneration conditions were examined in a central Maine beech stand harvested in both winter and summer with partial cutting and clearcuts. Initially, sprouts in winter cuts survived longer than those in summer cuts. After 10 years, we found that beech regeneration survival in the winter treatments continued to be higher than in the summer treatments. Disease-resistant American beech of high vigor left in clearcuts without the protection of surrounding trees were highly susceptible to decline and death from exposure. Leaving a small buffer of unharvested trees around resistant beech is recommended.


Rangifer ◽  
2011 ◽  
pp. 119-134 ◽  
Author(s):  
Michaela J. Waterhouse ◽  
Harold M. Armleder ◽  
Amanda F. L. Nemec

In west-central British Columbia, terrestrial lichens located in older, lodgepole pine (Pinus contorta) forests are important winter forage for woodland caribou (Rangifer tarandus caribou). Clearcut harvesting effectively removes winter forage habitat for decades, so management approaches based on partial cutting were designed to maintain continuous lichen-bearing habitat for caribou. This study tested a group selection system, based on removal of 33% of the forest every 80 years in small openings (15 m diameter), and two irregular shelterwood treatments (whole-tree and stem-only harvesting methods) where 50% of the stand area is cut every 70 years in 20 to 30 m diameter openings. The abundance of common terrestrial lichens among the partial cutting and no-harvest treatments was compared across five replicate blocks, pre-harvest (1995) and post-harvest (1998, 2000 and 2004). The initial loss of preferred forage lichens (Cladonia, Cladina, Cetraria and Stereocaulon) was similar among harvesting treatments, but there was greater reduction in these lichens in the openings than in the residual forest. After eight years, forage lichens in the group selection treatment recovered to pre-harvest amounts, while lichen in the shelterwood treatments steadily increased from 49 to 57% in 1998 to about 70% of pre-harvest amounts in 2004. Although not part of the randomized block design, there was substantially less lichen in three adjacent clearcut blocks than in the partial cuts. Regression analysis pre- and post-harvest indicated that increased cover of trees, shrubs, herbs, woody debris and logging slash corresponded with decreased forage lichen abundance. In the short-term, forestry activities that minimize inputs of woody debris, control herb and shrub development, and moderate the changes in light and temperatures associated with canopy removal will lessen the impact on lichen. Implementation of stand level prescriptions is only one aspect of caribou habitat management. A comprehensive approach should consider all factors and their interactions to maintain a viable population of woodland caribou in west-central British Columbia.


2011 ◽  
Vol 41 (5) ◽  
pp. 1082-1090 ◽  
Author(s):  
Rongzhou Man ◽  
James A. Rice ◽  
G. Blake MacDonald

Silvicultural options to obtain mixtures of broadleaved and conifer tree species in boreal forests remain limited, especially for mixtures of broadleaves and shade-intolerant conifers. In this study, we tested a series of treatment packages that included variation in harvesting pattern, site preparation, renewal treatments, and timing and patterns of tending to establish trembling aspen (Populus tremuloides Michx.) and jack pine (Pinus banksiana Lamb.) mixedwoods in intimate mixtures or spatial mosaics in northeastern Ontario. Preharvest spray resulted in fewer but better growth of aspen suckers compared with postharvest spray, which both reduced sucker density and decreased their vigour. Partial cutting reduced aspen regeneration in both the harvested and leave corridors but did not affect other broadleaved species, in this case predominantly red maple (Acer rubrum L.). After treatment, the rapid development of understory vegetation (shrubs, herbs, and grasses) and regeneration reduced total light transmittance at 0.5 m but had no effect at 4.0 m after 5 years. Future stands will be jack pine dominated following both pre- and post-harvest sprays, despite higher density, more uniform distribution, and better growth of broadleaved regeneration with preharvest spray, but will be balanced broadleaf and conifer mixtures in the partial cut areas.


1998 ◽  
Vol 76 (5) ◽  
pp. 872-883 ◽  
Author(s):  
Meiqin Qi ◽  
John B Scarratt

The effects of harvesting on seed bank dynamics in a boreal mixedwood forest were studied on replicated 10-ha treatment blocks harvested by different clear-cutting or partial-cutting systems in the fall of 1993. From 1994 to 1995 we monitored seed rain, soil seed banks, and seasonal changes in species composition in understory vegetation and seed banks in all harvest blocks plus three uncut controls. No persistent conifers were found in the soil seed banks of any treatment. The number of seeds of other species generally decreased with soil depth in all treatments, with the lower layer of organic soil yielding the highest numbers of seedlings. Many seeds of sedges and some herbs were found in the upper mineral soil horizon, indicating significant longevity. While disturbance by harvesting operations altered the distribution of seeds in the soil profile, harvesting method had little effect on the total number of species present in post-harvest seed banks or understory vegetation. There were no differences in seasonal compositional changes between treatments. Seed rain monitoring indicated that few conifer seeds were added to the seed bank. Betula papyrifera Marsh. was the dominant tree species in seed rain in the partial cutting treatments. However, in the second post-harvest year on clear cut sites sedges and grasses increased from less than 1 to 14% of seed rain. The results suggest that predominantly hardwood stands with prolific understory vegetation will initially develop on the treated sites, with a variable, but depleted conifer content.Key words: boreal mixedwood forest, natural regeneration, seed rain, seed bank, succession, vegetative propagation.


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