Five-year light, vegetation, and regeneration dynamics of boreal mixedwoods following silvicultural treatments to establish productive aspen–spruce mixtures in northeastern Ontario

2010 ◽  
Vol 40 (8) ◽  
pp. 1529-1541 ◽  
Author(s):  
Rongzhou Man ◽  
James A. Rice ◽  
G. Blake MacDonald
Keyword(s):  
Populus Tremuloides ◽  
Light Availability ◽  
Spatial Arrangement ◽  
Shrub Cover ◽  
Herbicide Application ◽  
Short Term ◽  
Partial Cutting ◽  
Silvicultural Treatments ◽  
Conifer Plantation ◽  
Boreal Mixedwoods

Given the extent of boreal mixedwoods in Canada and the challenges of maintaining their conifer component following harvest, we investigated the effects of intimate mixtures versus a mosaic spatial arrangement on mixedwood establishment and growth in northeastern Ontario. The silvicultural treatments were preharvest aerial herbicide spray, postharvest ground herbicide in conifer corridors, partial cutting, conventional conifer plantation with postharvest aerial herbicide, and an untreated reference stand. Fifth-year results suggest that preharvest herbicide application followed by clearcutting controlled trembling aspen ( Populus tremuloides Michx.) regeneration density and height growth nearly as effectively as postharvest herbicide in conifer corridors or the conventional conifer plantation treatments. Partial cutting reduced aspen regeneration in both harvested and leave corridors but did not affect shrub cover. Survival of spruce regeneration did not differ among silvicultural treatments; however, more spruce seedlings progressed from small to intermediate height classes in the preharvest spray and partial cut than in the postharvest herbicide treatment plots. Based on short-term responses in light availability, vegetation cover, and regeneration as well as cost comparisons among options, the treatment objectives were generally met: the stand has the desired species density and composition of a healthy and productive mixedwood.

Natural regeneration of white spruce in aspen-dominated boreal mixedwoods following harvesting

2010 ◽  
Vol 40 (3) ◽  
pp. 585-594 ◽  
Author(s):  
Jonathan Martin-DeMoor ◽  
Victor J. Lieffers ◽  
S. Ellen Macdonald
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Natural Regeneration ◽  
Boreal Forests ◽  
Weather Conditions ◽  
White Spruce ◽  
Woody Vegetation ◽  
Silvicultural Treatments ◽  
Boreal Mixedwoods ◽  
Time Of Harvest

In some boreal forests sites, there are considerable amounts of natural regeneration of white spruce ( Picea glauca (Moench) Voss) after logging, even without silvicultural treatments to encourage establishment. We assessed the factors controlling the amount of this regeneration 8–15 years postharvest on previously aspen-dominated ( Populus tremuloides Michx.) boreal mixedwood sites. We surveyed 162 transects across 81 cutovers, exploring the effects of mast years, season of harvest, distribution of seed trees, weather conditions around the time of harvest, and abundance of grass or woody vegetation on white spruce regeneration. Substantial amounts of naturally regenerated white spruce were found; however, sites with no seed trees had virtually no spruce regeneration. Average stocking was 7% (percentage of 9 m2 plots along a transect across a cutover that had at least one seedling), ranging from 0% to 62%. Stocking levels were higher in cutblocks that had been harvested in the summer, prior to seedfall of a mast year, and where there was a seed source within 60 m. Stocking was lower when conditions were cool and wet the year before and 2 years after harvest and when the site contained extensive cover of grass or woody vegetation.

Young Spruce-Fir Forests Released by Herbicides I. Response of Hardwoods and Shrubs

1992 ◽  
Vol 9 (4) ◽  
pp. 126-130 ◽  
Author(s):  
Michael Newton ◽  
Elizabeth C. Cole ◽  
Diane E. White ◽  
Maxwell L. McCormack
Keyword(s):  
High Rate ◽  
Shrub Cover ◽  
Short Term ◽  
Release Experiment ◽  
Total Cover ◽  
West Central ◽  
Herbicide Treatments ◽  
Phenoxy Herbicides

Abstract Responses of shrubs and hardwoods to 9 aerial herbicide treatments were evaluated in a replicated conifer-release experiment in a 7-year-old spruce-fir clearcut in west-central Maine. All herbicides and rates of application reduced hardwood and shrub cover by 50% or more in year 9, 2 years after treatment. Cover more than 1.5 m tall was nearly eliminated by treatments with triclopyr amine (Garlon 3A®), glyphosate (Roundup®), or a high rate of 2,4,5-T. Phenoxy herbicides (2,4-D and 2,4,5-T) led to short-term reductions in birches, maples, aspen, and raspberry, and little change in willows. Pin cherry was also controlled by these treatments but died out before year 16, regardless of whether it was sprayed. Untreated controls increased in total cover by about 50% between years 7 and 9 and also in abundance of cover >1.5 m tall. Much cover less than 1.5 m tall was left by all treatments other than triclopyr at a high rate. By the 16th year, major differences in height and cover still existed between all treatments and the controls. North. J. Appl. For. 9(4):126-130.

Phytoplankton photoadaptation during the spring period in Lake Zürich

1995 ◽  
Vol 32 (4) ◽  
pp. 59-62 ◽  
Author(s):  
Ferdinand Schanz ◽  
Judith Burri
Keyword(s):  
Species Composition ◽  
Light Availability ◽  
Plankton Community ◽  
Short Term ◽  
Spring Period ◽  
Constant Structure ◽  
Phytoplankton Communities ◽  
Lake Zürich

Long- and short-term photoadaptations as a response to increased light availability in spring phytoplankton communities in Lake Zürich have been investigated. At various stages fundamental changes in species composition and species adaptation in a plankton community of approximately constant structure were apparent.

Short-term Performance of Two Sulfonylurea Herbicides: Efficacy, Seedling Survival, and Growth

1995 ◽  
Vol 12 (2) ◽  
pp. 80-85
Author(s):  
Phillip E. Reynolds ◽  
Micheal J. Roden
Keyword(s):  
Black Spruce ◽  
Seedling Survival ◽  
Stem Volume ◽  
Silty Clay ◽  
Herbicide Application ◽  
Short Term ◽  
Growing Seasons ◽  
Survival And Growth ◽  
Term Performance ◽  
Survival Of Seedlings

Abstract Metsulfuron (ALLY or ESCORT), 36 and 72 g ai/ha (~ 0.5 and 1.0 oz ai/ac), and sulfometuron (OUST), 150, 300, and 450 g ai/ha (~ 2.1, 4.2, and 6.3 oz ai/ac), were applied to a northern New Brunswick clearcut (silty clay loam and silty clay soils) to reduce raspberry competition. Treatment, using skidder-mounted herbicide application equipment, occurred in May and August 1986, with planting of 2+2, bareroot, black spruce seedlings in June 1986 and in June 1987. Seedling survival and growth were measured yearly for 5 growing seasons after planting. By August 1991, raspberry cover was less in some treatments than in controls. Survival of seedlings planted 1 month after spring treatments was less than controls, and no significant stem volume increases were observed. Survival of seedlings planted approximately 1 yr after spring treatments was greater than that of control seedlings. Survival of seedlings planted after some summer treatments also was poor, and no significant stem volume increases were noted for seedlings planted after site preparation with sulfometuron. Optimal stem volume increases over control seedlings were observed for seedlings planted 1 yr after spring sulfometuron treatment. These increases occurred sooner than for seedlings planted 1 yr after spring metsulfuron treatment or after summer metsulfuron treatment. Fifth-year stem volume for these seedlings was correlated with raspberry cover (r² = 0.44), decreasing as raspberry cover increased. We conclude that the use of other less expensive silvicultural herbicides may provide equally effective raspberry control and better black spruce seedling survival and growth. North. J. Appl. For. 12(2):80-85.

Are mixtures of aspen and white spruce more productive than single species stands?

1999 ◽  
Vol 75 (3) ◽  
pp. 505-513 ◽  
Author(s):  
Rongzhou Man ◽  
Victor J. Lieffers
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
White Spruce ◽  
Single Species ◽  
Physical Separation ◽  
Soil Resource ◽  
Mixedwood Forests ◽  
Environmental Extremes ◽  
Spruce Stands ◽  
Boreal Mixedwoods

In boreal mixedwood forests, aspen (Populus tremuloides) and white spruce (Picea glauca) commonly grow in mixture. These species may avoid competition through differential shade tolerance, physical separation of canopies, phenological differences, successional separation, and differences in soil resource utilization. Aspen may also be able to positively affect the growth of white spruce by improving litter decomposition and nutrient cycling rates, controlling grass and shrub competition, ameliorating environmental extremes, and reducing pest attack. These positive relationships likely make mixed-species stands more productive than pure stands of the same species. The evidence regarding the productivity of pure versus mixed aspen/white spruce stands in natural unmanaged forests is examined in this paper. Key words: Tree mixture; productivity; boreal mixedwoods; aspen; white spruce

scholarly journals Coefficients de distribution de la régénération, cinq ans après des coupes avec protection des petites tiges marchandes appliquées dans des sapinières et des pessières noires du Québec

2011 ◽  
Vol 87 (05) ◽  
pp. 669-683 ◽  
Author(s):  
Martin Riopel ◽  
Jean Bégin ◽  
Jean-Claude Ruel
Keyword(s):  
Black Spruce ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Annual Rainfall ◽  
Deciduous Species ◽  
Partial Cutting ◽  
Coniferous Species ◽  
Breast Height ◽  
Silvicultural Treatments ◽  
Heavy Equipment

For certain mature forests dominated by balsam fir (Abies balsamea [L.] Mill.) or black spruce (Picea mariana [Mill.] BSP), it may be preferable to harvest trees with diameter at breast height greater than 15 cm while conserving smaller ones. This treatment, called harvesting with protection of small merchantable trees, produces strips, where partial cutting is applied, alternating with corridors, which are disturbed by heavy equipment during harvesting. This project studied stocking levels five years after treatment on 4896 sub-plots of 4 m2 in 22 blocks. Stocking coefficients (SC) for coniferous and deciduous species were modeled in order to identify variables affecting stocking. The strips had well-distributed coniferous regeneration, while SC in the corridors were more variable and lower, occasionally less than 60%. Black spruce-dominated sites were not as well stocked as balsam fir-dominated sites. Stocking levels of protected coniferous merchantable trees positively influence coniferous and deciduous SC in the corridors. The presence of coniferous species is also affected by harvest season and total annual rainfall. Alternative silvicultural treatments applicable in certain corridors are presented.

Linking deadwood-associated beetles and fungi with wood decomposition rates in managed black spruce forests1This article is one of a selection of papers from the International Symposium on Dynamics and Ecological Services of Deadwood in Forest Ecosystems.

2012 ◽  
Vol 42 (8) ◽  
pp. 1477-1490 ◽  
Author(s):  
Jenna M. Jacobs ◽  
Timothy T. Work
Keyword(s):  
Stand Structure ◽  
Black Spruce ◽  
Wood Decomposition ◽  
Decomposition Rates ◽  
Partial Cutting ◽  
Saprotrophic Fungi ◽  
Silvicultural Treatments ◽  
Saproxylic Beetle ◽  
Main Effects ◽  
The Relationship

Deadwood-associated insects and saprotrophic fungi are principal agents of wood decomposition in boreal forest. Silvicultural treatments that alter microclimate and availability of deadwood likely affect composition and growth rates of both insect and fungal communities, leading to changes in wood decomposition rates. Here, we relate both saproxylic beetle and dominant polypore assemblages with woody decomposition rates and environmental variables in experimental partial cuts, clearcuts, and uncut controls using a series of causal models to determine the relationship between stand structure, biodiversity, and ecosystem function in black spruce ( Picea mariana (Mill.) BSP) forests. Overall beetle and fungal composition differed between uncut stands and harvested stands. Main effects of harvesting included large increases in wood-feeding beetles and the fungus Gloeophyllum sepiarium (Wul.:Fr.) Karst. We suggest that these species were promoted by specific alterations in microhabitat conditions of deadwood. Within clearcuts specifically, changes in species composition and significantly more fungal degree-days resulted in significantly higher decomposition rates. We concluded that levels of partial cutting in the range of 15%–20% retention were not sufficient to maintain predisturbance communities but were sufficient to maintain wood decomposition rates similar to uncut stands.

scholarly journals Comparative leaf growth strategies in response to low-water and low-light availability: variation in leaf physiology underlies variation in leaf mass per area in Populus tremuloides

2017 ◽  
Vol 37 (9) ◽  
pp. 1140-1150 ◽  
Author(s):  
Alec S. Baird ◽  
Leander D.L. Anderegg ◽  
Melissa E. Lacey ◽  
Janneke HilleRisLambers ◽  
Elizabeth Van Volkenburgh
Keyword(s):  
Populus Tremuloides ◽  
Leaf Growth ◽  
Light Availability ◽  
Leaf Mass Per Area ◽  
Growth Strategies ◽  
Low Light ◽  
Leaf Mass ◽  
Leaf Physiology

scholarly journals POTENTIAL OF MULTI-TEMPORAL UAV-BORNE LIDAR IN ASSESSING EFFECTIVENESS OF SILVICULTURAL TREATMENTS

2017 ◽  
Vol XLII-2/W6 ◽  
pp. 393-397 ◽  
Author(s):  
U. Vepakomma ◽  
D. Cormier
Keyword(s):  
Resource Competition ◽  
Distribution Patterns ◽  
Forest Stand ◽  
Partial Cutting ◽  
Silvicultural Treatments ◽  
Short Period ◽  
The Difference ◽  
Silvicultural System ◽  
Individual Trees ◽  
Almost All

Silvicultural treatments are practiced to control resource competition and direct forest stand development to meet management objectives. Effective tracking of thinning and partial cutting treatments help in timely mitigation and ensuring future stand productivity. Based on a study conducted in autumn 2015, our findings in a white pine dominant forest stand in Petawawa (Ontario, Canada) showed that almost all individual trees were detectable, structure of individual trees and undergrowth was well pronounced and underlying terrain below dense undisturbed canopy was well captured with UAS based Riegl Vux-1 lidar even at a range of 150 m. Thereafter, the site was re-scanned the following summer with the same system. Besides understanding the difference in distribution patterns due to foliage conditions, co-registering the two datasets, in the current study, we tested the potential of quantifying effectiveness of a partial cutting silvicultural system especially in terms of filling of 3D spaces through vertical or lateral growth and mortality in a very short period of time.

Seasonal Response and Recovery of Eelgrass (Zostera marina) to Short-Term Reductions in Light Availability

2019 ◽  
Vol 43 (1) ◽  
pp. 120-134 ◽  
Author(s):  
Melisa C. Wong ◽  
Gwendolyn Griffiths ◽  
Benedikte Vercaemer
Keyword(s):  
Zostera Marina ◽  
Light Availability ◽  
Short Term ◽  
Response And Recovery
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