scholarly journals The effect of roots and litter of Calamagrostis canadensis on root sucker regeneration of Populus tremuloides

2007 ◽  
Vol 80 (4) ◽  
pp. 481-488 ◽  
Author(s):  
S. M. Landhausser ◽  
T. L. Mulak ◽  
V. J. Lieffers
Keyword(s):  
Populus Tremuloides ◽  
Calamagrostis Canadensis ◽  
Root Sucker

Wounding of aspen roots promotes suckering

2004 ◽  
Vol 82 (3) ◽  
pp. 310-315 ◽  
Author(s):  
Erin C Fraser ◽  
Victor J Lieffers ◽  
Simon M Landhäusser
Keyword(s):  
Populus Tremuloides ◽  
Growth Rates ◽  
Growing Season ◽  
Organic Layer ◽  
Trembling Aspen ◽  
Layer Depth ◽  
Injury Type ◽  
Organic Layers ◽  
Root Injury ◽  
Root Sucker

In early May, 1-m sections of trembling aspen (Populus tremuloides Michx.) roots in a forest cutblock were carefully exposed and examined for damage. Undamaged roots were subjected to one of three wounding treatments (scrape, sever, or uninjured control) and were then reburied to either the full normal organic layer depth or to one third of the normal depth. Following one growing season, the roots were reexposed and assessed for aspen sucker numbers and growth rates. Results indicate that injured roots produced suckers nearly twice as often as uninjured roots. Further, injured roots produced more suckers per root, and these suckers were taller and had greater leaf area. Roots buried under shallow organic layers also generated more suckers, regardless of injury type. The side of injury (distal or proximal) did not affect any of the measured variables. The present study suggests that moderate wounding of aspen roots increases initial sucker numbers and growth rates.Key words: trembling aspen, root sucker, root injury, regeneration.

Growth of Populus tremuloides in association with Calamagrostis canadensis

1998 ◽  
Vol 28 (3) ◽  
pp. 396-401 ◽  
Author(s):  
Simon M Landhäusser ◽  
Victor J Lieffers
Keyword(s):  
Populus Tremuloides ◽  
Inhibitory Effect ◽  
Root Competition ◽  
Total Biomass ◽  
Nutrient Regime ◽  
Calamagrostis Canadensis ◽  
Negative Effect ◽  
Soil Temperatures ◽  
Biomass Plant ◽  
Root Collar

Three experiments were conducted to examine the effects of Calamagrostis canadensis (Michx.) Beauv. on the growth of Populus tremuloides Michx. Containerized seedlings of P. tremuloides were transplanted into large pots and subjected to (1) three soil temperatures (20, 12, and 6°C), (2) root competition with C. canadensis, or (3) presence or absence of C. canadensis litter, each at two nutrient regimes. In the first experiment, significant differences (p = 0.0001) in pre- and neo-formed leaf area and root and shoot dry weights were observed for plants subjected to the three different soil temperatures. In experiment two, the presence of C. canadensis significantly (p < 0.001) reduced total biomass, plant height, and root collar calliper of P. tremuloides. In the third experiment, a significant interaction (p = 0.027) between C. canadensis litter and nutrient regime was observed, with the greatest inhibitory effect on P. tremuloides growth resulting from litter at the low nutrient regime. Low soil temperature had the strongest negative effect on P. tremuloides of the four factors investigated. However, direct competition with C. canadensis, low nutrient conditions, and C. canadensis litter likely would add to the growth suppression of P. tremuloides by this grass. The results of this study have significant implications for the management of P. tremuloides after harvesting.

scholarly journals Use of an Aspen Overstory to Control Understory Herbaceous Species, Bluejoint Grass (Calamagrostis canadensis), and Fireweed (Epilobium angustifolium)

2004 ◽  
Vol 21 (2) ◽  
pp. 74-79 ◽  
Author(s):  
Chris Maundrell ◽  
Chris Hawkins
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Ground Cover ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photosynthetic Photon Flux ◽  
Calamagrostis Canadensis ◽  
Canopy Opening ◽  
Epilobium Angustifolium

Abstract To enhance white spruce [Picea glauca (Moench) Voss] regeneration and growth, the potential for using an aspen (Populus tremuloides Michx.) overstory to suppress bluejoint grass [Calamagrostis canadensis (Michx.)] and fireweed (Epilobium angustifolium L) was investigated. Response to canopy opening was assessed on 10 treatments where the canopy had been incrementally opened. At the summer solstice, measurements of attenuated light were taken at 1.3 meters (breast height). Bluejoint grass and fireweed both responded with greater ground cover as the photosynthetic photon flux density increased (R2 = 0.84, P = 0.0002; R2 = 0.90, P = 0.0001; respectively). Where aspen has developed an overstory canopy, it may be possible to control competing vegetation to create favorable environmental conditions for spruce re-establishment, growth, and release while encouraging a sustainable mixedwood stand.

Dynamics of regeneration gaps following harvest of aspen stands

2006 ◽  
Vol 36 (7) ◽  
pp. 1818-1833 ◽  
Author(s):  
Daniel A MacIsaac ◽  
Philip G Comeau ◽  
S Ellen Macdonald
Keyword(s):  
Spatial Heterogeneity ◽  
Populus Tremuloides ◽  
Picea Glauca ◽  
Natural Disturbance ◽  
White Spruce ◽  
Deciduous Trees ◽  
Trembling Aspen ◽  
Calamagrostis Canadensis ◽  
Edaphic Conditions ◽  
Over Time

This study assessed the dynamics of gap development in postharvest regeneration in five stands in northwestern Alberta dominated by trembling aspen (Populus tremuloides Michx.). The pattern of gap development over time was determined from analysis of air photographs taken preharvest and 1, 4, 10, and 12 years postharvest. The area of each stand covered by gaps increased after harvest because of the addition of harvest-related gaps over and above those that had been present prior to harvest. The blocks we studied had a combined gap area of up to 29% of stand area 12 years postharvest. We measured regeneration characteristics, microsite, soil, light, and browse conditions in 30 aspen regeneration gaps (gaps in regeneration that were not gaps preharvest and were not due to obvious harvest-related disturbance) 14 years following harvest. Although deciduous trees within postharvest regeneration gaps were the same age as those outside (i.e., in a fully stocked matrix of newly established even-aged aspen stems), they were often suppressed, with significantly lower density and growth. Within the 14-year-old postharvest regenerating aspen stands, aspen height varied from 1 to 11 m; this substantial variability appeared to be largely due to the influence of browsing. There was little evidence of ongoing regeneration within postharvest regeneration gaps, indicating that these gaps will probably persist over time. This may impact future deciduous stocking and volume. It is unknown what may have initiated the formation of these gaps, although results suggest that they are not due to edaphic conditions or disease in the preharvest stands. There is evidence that bluejoint (Calamagrostis canadensis (Michx.) Beauv.) cover and browsing are important factors in the maintenance of postharvest regeneration gaps. The spatial heterogeneity resulting from gaps could be advantageous, however, either as part of ecosystem-based management emulating natural disturbance or as a template for mixedwood management, where white spruce (Picea glauca (Moench) Voss) are established in gaps.

Changes in the shrub and herb layers of vegetation after prescribed burning in Populus tremuloides woodland in southern Ontario

1978 ◽  
Vol 56 (15) ◽  
pp. 1792-1797 ◽  
Author(s):  
D. W. Smith ◽  
T. D. W. James
Keyword(s):  
Species Richness ◽  
Populus Tremuloides ◽  
Prescribed Burning ◽  
Canopy Cover ◽  
Abundant Species ◽  
Southern Ontario ◽  
Calamagrostis Canadensis ◽  
Cornus Stolonifera ◽  
Shrub Canopy ◽  
Microscale Heterogeneity

The undisturbed condition in the shrub and herb layers of a Populus tremuloides woodland in southern Ontario was characterized by a mosaic of two main vegetation groupings, one being relatively species rich and the other species poor. Their distribution was related chiefly to two environmental variables: (a) relative degree of shrub canopy cover, and (b) microtopographic position. Species-poor vegetation was associated with those sites having a closed shrub canopy and low, wet positions on the microtopographic gradient.Prescribed burning added a further dimension to the clumped pattern and species richness of the vegetation. Microscale heterogeneity created by the burns tended to increase species richness, but in general, richness was reduced by burning. Rapid postburn changes in the vegetation were largely restricted to shifts in dominance by the three most abundant species; Cornus stolonifera Michx., Calamagrostis canadensis (Michx.) Beauv., and Carex stricta var. strictior Lam. The changes in the dominants after burning appeared to be short lived but affected the overall structure of the shrub and herb vegetation.

Nitrogen uptake characteristics for roots of conifer seedlings and common boreal forest competitor species

2003 ◽  
Vol 33 (1) ◽  
pp. 156-163 ◽  
Author(s):  
Ryan D Hangs ◽  
J Diane Knight ◽  
Ken CJ Van Rees
Keyword(s):  
Boreal Forest ◽  
Populus Tremuloides ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
N Uptake ◽  
White Spruce ◽  
Jack Pine ◽  
Calamagrostis Canadensis ◽  
Successional Species ◽  
Menten Kinetic

Little is known about the N uptake abilities of competitor species and planted seedlings in the boreal forest. The objective of this study was to determine the Michaelis–Menten kinetic parameters of NH4+ and NO3– for white spruce (Picea glauca (Moench) Voss) and jack pine (Pinus banksiana Lamb.) seedlings, and three competitive common boreal forest early successional species: aspen (Populus tremuloides Michx.), fireweed (Epilobium angustifolium L.), and cala magrostis (Calamagrostis canadensis (Michx.) Beauv.). Uptake kinetics were measured in hydroponic cultures and expressed as maximum uptake (Imax) and ion affinity (Km). The ranking of Imax values (pmol·cm-2·s–1) for NH4+ uptake was calamagrostis (84.6), fireweed (58.1), white spruce (20.7), aspen (12.5), and jack pine (10.9), and for NO3– uptake was calamagrostis (17.7), fireweed (12.5), aspen (5.8), white spruce (4.5), and jack pine (2.1). The ranking of Km values (µM) for NH4+ uptake was calamagrostis (125.9), fireweed (163.8), aspen (205.7), white spruce (217.1), and jack pine (270.5), and for NO3– uptake was calamagrostis (229.9), fireweed (274.6), aspen (336.5), white spruce (344.5), and jack pine (350.5). Calamagrostis exhibited the greatest uptake rates and affinity for NH4+ and NO3–, suggesting that silviculture practices that specifically reduce establishment of this grass should benefit the growth of planted seedlings.

Competition and facilitation in mixtures of aspen seedlings, alfalfa, and marsh reedgrass

2004 ◽  
Vol 34 (9) ◽  
pp. 1858-1869 ◽  
Author(s):  
George W Powell ◽  
Edward W Bork
Keyword(s):  
Soil Moisture ◽  
Populus Tremuloides ◽  
Relative Yield ◽  
Herbaceous Species ◽  
Soil N ◽  
Negative Effects ◽  
Calamagrostis Canadensis ◽  
Growing Seasons ◽  
Successful Establishment ◽  
Increasing Demand

Increasing demand for aspen (Populus tremuloides Michx.) and related poplar species is generating interest in their intensive cultivation. Successful establishment of aspen plantations requires minimizing the negative effects of associated plant species. Competitive and facilitative effects were isolated in field plots containing fixed-density mixtures of aspen seedlings, alfalfa (Medicago sativa L.), and marsh reedgrass (Calamagrostis canadensis (Michx.) Beauv.) in central Alberta. Although aspen survival was unaffected in mixtures, damage to aspen leaf area was lower when grown with either herbaceous species than when grown in monoculture, possibly reflecting facilitation through plant defense guilds. Over the first two growing seasons, net competition was expressed as most aspects of aspen growth were reduced. Herbaceous species reduced photosynthetically active radiation, soil moisture, and soil N available to aspen. Moreover, relative yield totals from the species mixtures examined consistently indicated either neutral effects (combined yields equaled monoculture yields) or underyielding. Despite this, evidence of facilitation was also found when aspen was grown with alfalfa, including increases of overall available soil N and transient increases in soil moisture with pulsed precipitation during drought. These results indicate that short-term facilitative aspects of aspen–legume mixtures may be exploited through an agroforestry scheme by appropriately timed harvest of the herbaceous component. Conversely, aspen establishment has limited potential for integrated production with marsh reedgrass.

scholarly journals In-woods chipping: Possible evidence for allelochemical interaction of leachate generated from trembling aspen (Populus tremuloides Michx.) bark and wood waste

2001 ◽  
Vol 77 (2) ◽  
pp. 345-349 ◽  
Author(s):  
Timothy S. S. Conlin
Keyword(s):  
Populus Tremuloides ◽  
Lodgepole Pine ◽  
Height Growth ◽  
Control Treatment ◽  
Trembling Aspen ◽  
Regenerative Capacity ◽  
Wood Residue ◽  
Calamagrostis Canadensis ◽  
Paper Birch ◽  
Tree Length

A portable delimber-debarker-chipper, designed for in-woods chipping operations, was used to produce waste bark and wood residue from winter-harvested tree-length trembling aspen logs. The residue was then utilized to create leachate, which was subsequently used to treat white spruce, lodgepole pine, paper birch, aspen and Calamagrostis canadensis seedlings grown in sand-filled pots. Treatment with the leachate significantly decreased height growth and shoot and root dry weights of all species relative to the control treatment. Root: shoot ratios of all tree species except lodgepole pine were increased significantly by application of leachate. The root: shoot ratios of treated C. canadensis were significantly increased during one season, but significantly reduced in the following season. The data indicated that leachate from aspen bark and wood residue contain allelochemical properties that could affect the regenerative capacity of aspen cutblocks harvested for in-woods chipping operations. Key words: aspen, leachate, allelochemistry, Populus tremuloides, in-woods chipping

Impact of chipping residues and its leachate on the initiation and growth of aspen root suckers

2007 ◽  
Vol 87 (4) ◽  
pp. 361-367 ◽  
Author(s):  
Simon M Landhäusser ◽  
Victor J Lieffers ◽  
Pak Chow
Keyword(s):  
Phenolic Compounds ◽  
Populus Tremuloides ◽  
Thick Layer ◽  
Root Systems ◽  
Water Soluble ◽  
The Other ◽  
Similar Amount ◽  
Physical Barrier ◽  
Root Sucker ◽  
Root Suckers

Field chipping operations often disperse chipping residues of bark and branches in layers or piles in cut-overs. We tested the effects of these residues on the root sucker regeneration of aspen (Populus tremuloides Michx.), using root systems established in large pots. After decapitation of the stems, the root systems were covered with a 4 cm thick layer of chipping residues. Other root systems were treated with an extract of the water-soluble compounds leached from a similar amount of residues while others were left untreated as controls; all three treatments were left to sucker for 7 wk. There were no differences in the number of root suckers that were initiated on the aspen root system among the three treatments. There were, however, significantly lower numbers of suckers that emerged through the chipping residue and their emergence was delayed relative to the other treatments. The delay in emergence and the reduction in sucker numbers were likely a result of the residues acting as a physical barrier. After 7 wk, concentrations of water-soluble phenolic compounds, sugars, and carbon from the chipping residues were elevated in the soil; however, they appeared to be below a level that affects sucker emergence and development. Key words: Allelochemistry, leachate, physical barrier, Populus tremuloides, regeneration

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