The Biology of Canadian Weeds. 146. Rhododendron groenlandicum (Oeder) Kron and Judd

2011 ◽  
Vol 91 (4) ◽  
pp. 725-738 ◽  
Author(s):  
François Hébert ◽  
Nelson Thiffault
Keyword(s):  
Soil Nitrogen ◽  
Organic Nitrogen ◽  
Forest Canopy ◽  
Black Spruce ◽  
Acidic Soils ◽  
Nitrogen And Phosphorus ◽  
Boreal Ecosystems ◽  
Water Dispersal ◽  
Labrador Tea ◽  
Forest Openings

Hébert, F. and Thiffault, N. 2011. The Biology of Canadian Weeds. 146. Rhododendron groenlandicum (Oeder) Kron and Judd. Can. J. Plant Sci. 91: 725–738. Rhododendron groenlandicum (Oeder) Kron and Judd, bog Labrador tea, is an evergreen shrub from the Ericacae family native to North America. Bog Labrador tea is associated with the later stages of forest successions in black spruce forest stands of the boreal ecosystems with cool climates, but responds aggressively to forest openings where it is already present. In general, bog Labrador tea is associated with nutrient-poor, acidic soils, with drainage ranging from moist to wet. Layering is the main regeneration strategy of the species; evidence suggests that this could be especially true following disturbances that open the forest canopy. Sexual reproduction maintains viability in undisturbed communities through wind or water dispersal. Rhododendron groenlandicum acclimates more rapidly relative to black spruce after perturbations through a higher rate of resource utilization when resources are available. The species is a highly competitive shrub for soil nutrients; it competes with regenerating conifers for soil nitrogen and phosphorus. It can also assimilate organic nitrogen from the soil through its mycorhizae. These characteristics may lead to the formation of ericaceous heaths that can stay unforested indefinitely. However, this species can be eradicated by herbicides (glyphosate) and heavy site scarification can limit its propagation.

Changes in DOC and DON fluxes in response to harvest intensity of black-spruce-dominated forest ecosystems in northwestern Ontario

2009 ◽  
Vol 89 (1) ◽  
pp. 67-79 ◽  
Author(s):  
Dave M Morris
Keyword(s):  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Black Spruce ◽  
Site Type ◽  
Northwestern Ontario ◽  
Clearcut Harvesting ◽  
Second Year ◽  
Forest Floors ◽  
Source Sink ◽  
Site Types

The current study was conducted to quantify and compare dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) fluxes through black-spruce-dominated forests, to compare the source/sink characteristics of sphagnum- versus feathermoss-dominated forest floors, and to identify changes in DOC and DON flow patterns occurring as a result of clearcut harvesting. After 2 yr of pre-harvest monitoring, replicated, experimental harvests of varying intensities of biomass removals were conducted followed by 4 yr of post-harvest sampling. Prior to harvest, the upland site type, dominated by feathermoss, was a significant source of DOC and DON, whereas, the wet-sphagnum-dominated sites exported minor amounts of these solutes. After harvest, DOC and DON fluxes peaked in the second year, but then dropped off significantly to at or below pre-harvest levels. On the upland site type, chipper debris appeared to be a major source of DOC and DON generating fluxes well above the pre-harvest levels. On the wetter site types, it appeared that microclimate differences between harvest treatments had a stronger influence on DOC and DON production than did the amount or type of harvest residue. Full-tree harvesting did not significantly alter the production of DOC and DON when compared with stem-only harvesting on the sites included in this study. Key words: DOC, DON, forest floor leachate, black spruce, harvesting response

Prescribed burning for lowland black spruce regeneration in northern Minnesota

1984 ◽  
Vol 14 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Scott E. Aksamit ◽  
Frank D. Irving
Keyword(s):  
Prescribed Burning ◽  
Black Spruce ◽  
Controlled Study ◽  
University Of Minnesota ◽  
Feather Moss ◽  
Wide Range ◽  
Labrador Tea ◽  
Tall Shrub ◽  
The University ◽  
Larger Sample

Concern over the variability of black spruce (Piceamariana (Mill.) B.S.P.) regeneration on peatlands in northern Minnesota following prescribed burning led to a cooperative study between the University of Minnesota and the Minnesota Department of Natural Resources. Twenty-seven black spruce cutovers on State lands that had been prescribed burned and either seeded or left to regenerate naturally were sampled. These were stratified into sphagnum – Labrador-tea – leather-leaf (SPHG) sites (10), feather moss (FM) sites (9), and alder – graminoid – other tall shrub (ALDR) sites (8). Results indicate that fire was not necessary to regenerate SPHG sites. FM sites required fire to modify unfavorable seedbeds and to reduce competition. Best results were obtained by burning when the upper layers of the peat were highly desiccated. ALDR sites occupied a wide range of ecological conditions which led to highly variable regeneration results. A larger sample size and possibly more carefully controlled study conditions are needed to fully understand ALDR site regeneration. Seeding results were uncertain for all sites.

Interaction of ethylaluminum dichloride with organic nitrogen and phosphorus compounds in three-component polyolefin catalysts

1965 ◽  
Vol 3 (6) ◽  
pp. 2135-2147
Author(s):  
Richard L. McConnell ◽  
Marvin A. McCall ◽  
G. O. Cash ◽  
F. B. Joyner ◽  
H. W. Coover
Keyword(s):  
Organic Nitrogen ◽  
Phosphorus Compounds ◽  
Nitrogen And Phosphorus

scholarly journals Improved ultraviolet photo‐oxidation system yields estimates for deep‐sea dissolved organic nitrogen and phosphorus

2019 ◽  
Vol 17 (4) ◽  
pp. 277-291 ◽  
Author(s):  
Rhea K. Foreman ◽  
Karin M. Björkman ◽  
Craig A. Carlson ◽  
Keri Opalk ◽  
David M. Karl
Keyword(s):  
Deep Sea ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Nitrogen And Phosphorus ◽  
Photo Oxidation ◽  
Oxidation System

scholarly journals Grouseberry (Vaccinium scoparium Leiberg ex Coville) fruit production in forest openings in Banff National Park, Alberta

2015 ◽  
Vol 128 (4) ◽  
pp. 400 ◽  
Author(s):  
Ian Pengelly ◽  
David Hamer
Keyword(s):  
National Park ◽  
Forest Canopy ◽  
Fruit Production ◽  
Fire Disturbance ◽  
Subalpine Forest ◽  
Prescribed Burns ◽  
Banff National Park ◽  
Open Forest ◽  
Understory Shrubs ◽  
Forest Openings

Grouseberry (Vaccinium scoparium Leiberg ex Coville) is an abundant dwarf shrub in the understory of many areas of subalpine forest in Banff National Park and has the potential to produce fruit important for wildlife. However, the suppression and prevention of wildfires, which began in the early 1900s in the park, have reduced fire-dependent shrubland and open forest and increased the extent of closed, mature forest. Because canopy closure is typically associated with decreased fruit production by understory shrubs, the decline in fire disturbance may be reducing Grouseberry fruit production. To quantify this effect, we measured Grouseberry fruit production under various forest canopies at 10 sites in Banff during 2004–2012. We measured site openness by modeling photosynthetically active direct solar radiation (dPAR) adjusted for overshadowing by topography and coniferous foliage. We found a positive relation between Grouseberry fruit production and dPAR in 2006 and 2010–2012, but not in 2008 or 2009, the 2 years of lowest fruit production; data were lacking for 2004, 2005, and 2007. We also recorded high Grouseberry fruit densities beginning 5 years after fire removed the forest canopy in four prescribed burns conducted during 2001: fruit production was 3.3 to more than 20 times that in adjacent mature forests in 5 of the 6 years analyzed. This study shows the potential ecological benefits of both prescribed burns and wildfire in upper subalpine forests where Grouseberry is widespread, but fruit production is low under the forest canopy.

scholarly journals Grazing impacts on soil nitrogen and phosphorus under Parkland pastures.

2006 ◽  
Vol 54 (6) ◽  
Author(s):  
V.S. Baron ◽  
A.C. Dick ◽  
E. Mapfumo ◽  
S.S. Malhi ◽  
M.A. Naeth ◽  
...  
Keyword(s):  
Soil Nitrogen ◽  
Nitrogen And Phosphorus ◽  
Grazing Impacts
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