Mechanisms of interaction between Kalmia angustifolia cover and Picea mariana seedlings

2002 ◽  
Vol 32 (11) ◽  
pp. 2022-2031 ◽  
Author(s):  
Anna Wallstedt ◽  
Andrew Coughlan ◽  
Alison D Munson ◽  
Marie-Charlotte Nilsson ◽  
Hank A Margolis
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Water Soluble ◽  
Organic Layer ◽  
Belowground Competition ◽  
Soil Microbial ◽  
Kalmia Angustifolia ◽  
Seedling Biomass ◽  
Soluble Phenols ◽  
Different Levels

Sites dominated by Kalmia angustifolia L. are often associated with slow decomposition of organic matter, decreased nitrogen (N) mineralization rates, and low black spruce (Picea mariana (Mill.) BSP) productivity. The objective of this study was to separate the effects of belowground competition by Kalmia from the effects of water-soluble soil phenols on black spruce seedlings growing under different levels of Kalmia cover. A factorial greenhouse bioassay was established in which black spruce seedlings were grown for 6 months in intact blocks of soil with three different levels of Kalmia cover. The soil was treated with charcoal to reduce the amounts of water-soluble phenols, and (or) tubes were inserted to exclude Kalmia roots. At low Kalmia cover, reducing the level of belowground competition increased seedling biomass by 134%. However, reducing belowground competition did not increase seedling biomass at the two higher levels of Kalmia cover. It is possible that seedling biomass remained low because of an increased immobilization of N in the organic layer. Furthermore, the proportion of ectomycorrhiza morphotypes differed among seedlings growing under different levels of Kalmia cover. The effect of water-soluble phenols on seedling growth remains uncertain, since we observed a confounding effect of the charcoal treatment on soil microbial biomass and seedling response.

Growth and nitrogen retranslocation of nutrient loaded Picea mariana seedlings planted on boreal mixedwood sites

2001 ◽  
Vol 31 (8) ◽  
pp. 1357-1366 ◽  
Author(s):  
Moses Imo ◽  
Victor R Timmer
Keyword(s):  
Picea Mariana ◽  
Nutrient Loading ◽  
Black Spruce ◽  
N Uptake ◽  
Nutrient Mobilization ◽  
N Accumulation ◽  
Northern Ontario ◽  
Nursery Culture ◽  
Forest Sites ◽  
Seedling Biomass

Enhanced nutrient mobilization from old to current growth is a key mechanism that confers competitive ability to nutrient-loaded black spruce (Picea mariana (Mill.) BSP) seedlings planted on high-competition forest sites in northern Ontario. This study examines effects of nutrient loading and differing vegetation management (herbicide, fertilization, shading) on growth, partitioning, and net retranslocation of N between current and old shoots of newly planted black spruce seedlings on six contrasting boreal sites. Nutrient loading during nursery culture improved seedling growth and N uptake and retranslocation after transplanting. Herbicide application accelerated growth and N uptake only on the high-competition Alnus, hardwood, and mixedwood sites but had no effect on the less competitive feathermoss and Vaccinium sites. Weed removal on competitive sites reduced N retranslocation significantly. Field fertilization reduced N retranslocation in seedlings and promoting tree growth and N uptake on the less competitive feathermoss and Vaccinium sites. However, fertilization stimulated weeds on high-competition sites suppressing seedling biomass and N uptake. Factors that seem to affect net N retranslocation include the type and level of internal N reserves, biomass and N accumulation and partitioning, external N supply, and other stresses that limit plant growth such as competition.

Dynamics and morphology of giant circular patterns of low tree density in black spruce stands in northern Quebec

2001 ◽  
Vol 79 (4) ◽  
pp. 420-428 ◽  
Author(s):  
Jean-François Giroux ◽  
Yves Bergeron ◽  
Jean J Veillette
Keyword(s):  
Surface Water ◽  
Picea Mariana ◽  
Black Spruce ◽  
Mineral Soil ◽  
Tree Density ◽  
Surface Elevation ◽  
Organic Layer ◽  
Spruce Stands ◽  
Spruce Mortality ◽  
Soil Measurements

Giant circular patterns of low tree density in black spruce (Picea mariana) stands were investigated in the Abitibi region of Quebec. We used dendrochronological techniques to test the hypotheses that ring patterns of low tree density are caused either by radial changes in spruce mortality or productivity. Seven circles were sampled. We found no gradient in the age of spruce along circle radii suggesting that rings of low tree density do not expand radially, that is, they are not spatially dynamic entities. The results indicate, however, that spruce trees were less dense and productive within the rings due to excessive moisture in the soil. Measurements of surface elevation, thickness of the organic layer and elevation of the mineral substrate across the circles revealed that a depression in the mineral soil beneath the rings traps the surface water and this area of poor drainage seems to prevent the establishment of black spruce within the rings. The origin of the ring-shaped depressions was attributed to geological or geomorphological causes.Key words: black spruce, Picea mariana, mortality, productivity, rings, geomorphology.

The response of root and microbial respiration to the experimental warming of a boreal black spruce forest

2014 ◽  
Vol 44 (8) ◽  
pp. 986-993 ◽  
Author(s):  
Jason G. Vogel ◽  
Dustin Bronson ◽  
Stith T. Gower ◽  
Edward A.G. Schuur
Keyword(s):  
Picea Mariana ◽  
Microbial Respiration ◽  
Black Spruce ◽  
Control Treatment ◽  
Prolonged Release ◽  
Spruce Forest ◽  
Experimental Warming ◽  
Soil Microbial ◽  
Respiration Rates ◽  
And Control

We investigated the effects of a 5 °C soil + air experimental heating on root and microbial respiration in a boreal black spruce (Picea mariana (Mill.) B.S.P.) forest in northern Manitoba, Canada, that was warmed between 2004 and 2007. In 2007, the 14C/12C signatures of soil CO2 efflux and root and soil microbial respiration were used in a two-pool mixing model to estimate their proportional contributions to soil CO2 efflux and to examine how each changed in response to the warming treatments. In laboratory incubations, we examined whether warming had altered microbial respiration rates or microbial temperature sensitivity. The 14C/12C signature of soil CO2 efflux and microbial respiration in the heating treatments were both significantly (p < 0.05) enriched relative to the control treatment, suggesting that C deposited nearer the atmospheric bomb peak in 1963 contributed more to microbial respiration in heated than control treatments. Soil CO2 efflux was significantly greater in the heated than control treatments, suggesting the acclimation to temperature of either root or microbial respiration was not occurring in 2007. Microbial respiration in laboratory incubations was similar in heated and control soils. This study shows that microbial respiration rates still responded to temperature even after 4 years of warming, highlighting that ecosystem warming can cause a prolonged release of soil organic matter from these soils.

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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