scholarly journals Twenty-five years post-treatment conifer responses to silviculture on a Kalmia-dominated site in eastern Canada

2017 ◽  
Vol 93 (02) ◽  
pp. 161-170 ◽  
Author(s):  
Nelson Thiffault ◽  
Brian D. Titus ◽  
Basil English
Keyword(s):  
Pinus Banksiana ◽  
Black Spruce ◽  
Eastern Canada ◽  
Positive Effects ◽  
Kalmia Angustifolia ◽  
Silvicultural Treatments ◽  
Stand Productivity ◽  
Soil Scarification ◽  
Productivity Gains

Research has demonstrated the potential of soil scarification, fertilization, and herbicide application to improve conifer seedling establishment and early growth. However, tree responses to and interactions among silvicultural treatments vary, making it difficult to predict mid- and long-term impacts of silviculture on stand productivity. We thus evaluated the 25-year effects of scarification and herbicide–fertilization combinations on black spruce (Picea mariana), jack pine (Pinus banksiana) and tamarack (Larix laricina) planted on a Kalmia angustifolia-dominated site. Our results show that the effects of scarification and herbicide–fertilization combinations diverged among species. Black spruce was the most responsive species to scarification for height and diameter at breast height. The combination of herbicide and fertilization treatments still had significantly positive effects on the long-term height and diameter growth of all species. Silvicultural treatments resulted in significant reductions in rotation length (based on height) when compared to height in nontreated-plots, depending on the species; reductions in years to attain a given height were greater for black spruce than for the other species. Our results illustrate the need to take species autecology into account when predicting productivity gains associated with early silviculture, and to provide managers with specific guidelines for the reforestation of ericaceous-dominated sites in Canadian boreal ecosystems.

scholarly journals Deep Planting Has No Short- or Long-Term Effect on the Survival and Growth of White Spruce, Black Spruce, and Jack Pine

2011 ◽  
Vol 28 (3) ◽  
pp. 146-151 ◽  
Author(s):  
Alain Paquette ◽  
Jean-Pierre Girard ◽  
Denis Walsh
Keyword(s):  
Black Spruce ◽  
White Spruce ◽  
Jack Pine ◽  
Eastern Canada ◽  
Planting Depth ◽  
Early Results ◽  
Significant Difference ◽  
Negative Effect ◽  
Tukey Honestly Significant Difference

Abstract Although studies in the past have reported that the deeper planting of conifers has no effect on seedling performance, most planting guidelines in use today still recommend that seedlings be planted to the rootcollar. Past studies were mostly observational, used bareroot seedlings, and often reported early results from just one or two depths of planting treatments. Most of the results available regarding planting depth for boreal species are anecdotal, although they are planted by the hundreds of millions every year. The present study reports no short-term (1 year) or long-term (15 to 19 years) negative effect of planting depth on the survival and height and diameter growth of black spruce, white spruce, and jack pine seedlings over three large, replicated experiments in the boreal forest of eastern and northern Quebec (eastern Canada). Four different depth treatments were compared, from manual planting at the rootcollar to the deepest mechanical planting treatment at 10 cm or more, making this the largest, longest-lasting study of its kind. Although, as expected, important differences in growth were present between species, all three commonly planted conifers reacted similarly to the planting depth treatments (no effect). This result can in part be attributed to an almost perfect control of frost heaving in the deepest two treatments. Planting depth effects were assessed using analysis of variance, multiple Tukey honestly significant difference, and uncorrected pairwise one-tailed t-tests to increase the probability of detecting a negative effect. Absolute differences and effect sizes (generally small and often positive with greater depths) were also analyzed.

scholarly journals Impact of soil scarification on reindeer pastures

Rangifer ◽  
1990 ◽  
Vol 10 (3) ◽  
pp. 99 ◽  
Author(s):  
Olof Eriksson ◽  
Tuomo Raunistola
Keyword(s):  
Standard Procedure ◽  
Plant Cover ◽  
Point Of View ◽  
Ground Vegetation ◽  
Long Term Effects ◽  
Surface Moisture ◽  
Positive Effects ◽  
Soil Scarification ◽  
Soil Temperatures

During recent years, soil scarification has become a standard procedure for improving seed beds after logging. Around 57 000 ha were treated, primarily through harrowing and ploughing, in the counties of Vâsterbotten and Norbotten during 1985. The positive effects of scarification, from a forestry point of view, are improved access to plant nutrients, raised soil temperatures and reduces surface moisture. The aim of the present study was to describe long-term changes in the ground vegetation following scarification. Harrowing affects 45-55% of the plant cover while ploughing affects 65-90%. 10 years after ploughing and harrowing about 20% of the surface is still without vegetation. Real long-term effects remain in dispute. It has been claimed that ploughing, at least, may lead to irreversible changes.

scholarly journals Modelling Post-Disturbance Successional Dynamics of the Canadian Boreal Mixedwoods

Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 3 ◽  
Author(s):  
Kobra Maleki ◽  
Mohamadou Alpha Gueye ◽  
Benoit Lafleur ◽  
Alain Leduc ◽  
Yves Bergeron
Keyword(s):  
Spruce Budworm ◽  
Eastern Canada ◽  
Species Dominance ◽  
Silvicultural Treatments ◽  
Composition And Structure ◽  
Long Time ◽  
Successional Stages ◽  
Boreal Mixedwoods ◽  
Natural Dynamics

Natural disturbances, such as fire and insect outbreaks, play important roles in natural forest dynamics, which are characterized over long time scales by changes in stand composition and structure. Individual-based forest simulators could help explain and predict the response of forest ecosystems to different disturbances, silvicultural treatments, or environmental stressors. This study evaluated the ability of the SORTIE-ND simulator to reproduce post-disturbance dynamics of the boreal mixedwoods of eastern Canada. In 1991 and 2009, we sampled all trees (including seedlings and saplings) in 431 (256 m2) plots located in the Lake Duparquet Research and Teaching Forest (western Quebec). These plots were distributed in stands originating from seven wildfires that occurred between 1760 and 1944, and which represented a chronosequence of post-disturbance stand development. We used the 1991 inventory data to parameterize the model, and simulated short- to long-term natural dynamics of post-fire stands in both the absence and presence of a spruce budworm outbreak. We compared short-term simulated stand composition and structure with those observed in 2009 using a chronosequence approach. The model successfully generated the composition and structure of empirical observations. In long-term simulations, species dominance of old-growth forests was not accurately estimated, due to possible differences in stand compositions following wildfires and to differences in stand disturbance histories. Mid- to long-term simulations showed that the secondary disturbance incurred by spruce budworm did not cause substantial changes in early successional stages while setting back the successional dynamics of middle-aged stands and accelerating the dominance of white cedar in late-successional post-fire stands. We conclude that constructing a model with appropriate information regarding stand composition and disturbance history considerably increases the strength and accuracy of the model to reproduce the natural dynamics of post-disturbance boreal mixedwoods.

Forest productivity after careful logging and fire in black spruce stands of the Canadian Clay Belt

2016 ◽  
Vol 46 (6) ◽  
pp. 783-793 ◽  
Author(s):  
Cécile Leroy ◽  
Alain Leduc ◽  
Nelson Thiffault ◽  
Yves Bergeron
Keyword(s):  
Organic Matter ◽  
Sustainable Forest Management ◽  
Black Spruce ◽  
Growth Potential ◽  
Juvenile Growth ◽  
Eastern Canada ◽  
Lower Growth ◽  
Soil Thickness ◽  
Study Region ◽  
Stand Productivity

Some regenerating stands of the boreal forest exhibit low juvenile growth after major disturbances, which compromises sustainable forest management objectives. In black spruce – feather moss stands of eastern Canada subject to paludification, careful logging methods could decrease stand productivity with time by preventing a beneficial reduction in organic soil thickness. The aim of this project was to confirm decreases in juvenile growth between stands originating from careful logging and the former stands originating from old fires on the same sites. Stem analyses showed that stands originating from CPRS had significantly better juvenile height growth than the former stands but significantly lower growth than stands originating from recent fire in the study region. If organic matter thickness apparently played a role in the growth differences observed between fire and harvesting, it was not the only factor determining stand productivity. According to our results, cohort status, climatic regime, and quality of the residual organic matter are other factors that seem to drive productivity. Our results show that postharvest management approaches (e.g., site preparation) should be used to increase yields after harvest for the sites to express their full growth potential.

Silviculture and planted species interact to influence reforestation success on a Kalmia-dominated site – a 15-year study

2010 ◽  
Vol 86 (2) ◽  
pp. 234-242 ◽  
Author(s):  
Nelson Thiffaul ◽  
Brian D Titus ◽  
Martin T Moroni
Keyword(s):  
Sustainable Forest Management ◽  
Black Spruce ◽  
Natural Disturbance ◽  
Vegetation Management ◽  
Jack Pine ◽  
Volume Index ◽  
Canopy Closure ◽  
Conifer Species ◽  
Kalmia Angustifolia ◽  
Silvicultural Treatments

Successful regeneration following harvesting or natural disturbance is a fundamental prerequisite for sustainable forest management. However, some regenerating stands have poor juvenile growth rates, which compromise sustainable management objectives. In particular, the presence of some ericaceous species that proliferate after forest disturbance, such as Kalmia angustifolia, can slow succession of boreal stands to the point that ecosystem retrogression is induced. We used data from a silvicultural field trial established in central Newfoundland to evaluate how various combinations of silvicultural treatments (trench scarification, herbicide application, fertilization at planting) influenced growth of three conifer species planted on a Kalmia-dominated cutover. Ground-level diameter (GLD), height, diameter at breast height (DBH), and percent Kalmia cover were assessed at the end of 15 growing seasons after planting. We detected several interactions between silvicultural treatments and planted conifer species. Globally, height and estimates of foliar biomass of all conifer species responded positively to scarification. Fifteen-year height in both scarified and unscarified treatments was in the order Picea mariana < Pinus banksiana < Larix laricina. Black spruce and jack pine height increased when Kalmia was controlled with herbicide, but height of tamarack was not. The use of herbicide significantly increased 15-year GLD and volume index of all three conifer species, but only black spruce responded positively to fertilization at planting. Our results confirm that species-specific responses to silvicultural treatments are to be expected when managing Kalmia-dominated sites. Although chemical vegetation management has great silvicultural potential, our results suggest that mechanical site preparation can also be effective in promoting early conifer seedling growth that leads to rapid canopy closure. It is anticipated that canopy closure will lead to exclusion of Kalmia later in the rotation through natural successional pathways. Key words: Kalmia angustifolia, vegetation management, scarification, herbicide, fertilizer, black spruce, jack pine, tamarack

scholarly journals Growth release of stunted black spruce (Picea mariana) in Kalmia heath: the role of ectomycorrhizal fungi and near-ground microclimate

2016 ◽  
Vol 46 (5) ◽  
pp. 666-673 ◽  
Author(s):  
Philippe St. Martin ◽  
Azim U. Mallik
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Chemical Properties ◽  
Root Tips ◽  
Eastern Canada ◽  
Stunted Growth ◽  
Growth Release ◽  
Kalmia Angustifolia ◽  
Significant Difference ◽  
Ecm Fungi

Naturally regenerating and planted black spruce (Picea mariana (Mill.) B.S.P.) in post-fire landscapes in eastern Canada often exhibit stunted growth in the presence of ericaceous shrubs such as Kalmia angustifolia L. After a period of stunted growth, some seedlings experience a growth release, exhibiting growth rates closer to normally growing seedlings. We hypothesized that an increase in colonization of root tips by ectomycorrhizal (ECM) fungi is responsible for this release and that the percentage of root tips colonized by ECM fungi would be higher on seedlings that had a released or normally growing neighbour within close proximity. We quantified ECM fungi diversity and abundance from 255 soil cores from stunted, released, and normally growing black spruce seedlings sampled in two Kalmia-dominated sites in Newfoundland. Growth and microsite characteristics around each seedling were also measured. We found that normal and released seedlings had significantly higher proportions of ECM fungi root tips than stunted seedlings, supporting our final hypothesis; however, there was no significant difference in distance between neighbours. Soil chemical properties are thought to inhibit the vegetative spread of ECM fungi species in this particular system and are identified as an important topic for further research.

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