Needle properties of host white spruce (Picea glauca [Moench] Voss) experiencing eastern dwarf mistletoe (Arceuthobium pusillum Peck) infections of differing severity

Botany ◽  
2017 ◽  
Vol 95 (3) ◽  
pp. 295-305 ◽  
Author(s):  
Johnathon A. de Villier ◽  
Jaret S. Reblin ◽  
Barry A. Logan
Keyword(s):  
Picea Glauca ◽  
Photosynthetic Capacity ◽  
Full Range ◽  
Severe Infection ◽  
White Spruce ◽  
Biochemical Properties ◽  
Dwarf Mistletoe ◽  
Needle Size ◽  
The Impact ◽  
Physiological And Biochemical

Eastern dwarf mistletoe (Arceuthobium pusillum Peck) parasitizes the branches of white spruce (Picea glauca [Moench] Voss) and ultimately kills this host species. Previous studies of host needle physiology generally focused on trees experiencing infections of moderate severity; here, we expanded upon previous research to investigate the morphological, physiological, and biochemical properties of needles from white spruce trees experiencing the full range of infection severities. We found that the impact of parasitism on host needle parameters did not scale uniformly with infection severity. Rather, parasitism reduced host needle size distal to infection and resulted in more negative carbon isotope ratios across all infection severities. Reduced foliar nitrogen and chlorophyll content were only evident in trees with moderate or severe infection, while photosynthetic capacity was depressed in only severely infected trees. Furthermore, while some impacts were confined to infected host branches, others, such as smaller needles and reduced photosynthetic capacity, were also evident in branches showing no visible signs of infection. We conclude that symptoms of infection appearing only after infection worsened in severity or appearing in uninfected branches may in whole or in part also be manifestations of a decline in resource availability and vigor of the whole tree.

scholarly journals Biology and Role of Extracellular Vesicles (EVs) in the Pathogenesis of Thrombosis

2019 ◽  
Vol 20 (11) ◽  
pp. 2840 ◽  
Author(s):  
Marta Zarà ◽  
Gianni Francesco Guidetti ◽  
Marina Camera ◽  
Ilaria Canobbio ◽  
Patrizia Amadio ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Cell Communication ◽  
Parental Cell ◽  
Biochemical Properties ◽  
Protein Markers ◽  
Surface Receptors ◽  
The Impact ◽  
Physiological And Biochemical ◽  
Physiological And Biochemical Properties

Extracellular vesicles (EVs) are well-established mediators of cell-to-cell communication. EVs can be released by every cell type and they can be classified into three major groups according to their biogenesis, dimension, density, and predominant protein markers: exosomes, microvesicles, and apoptotic bodies. During their formation, EVs associate with specific cargo from their parental cell that can include RNAs, free fatty acids, surface receptors, and proteins. The biological function of EVs is to maintain cellular and tissue homeostasis by transferring critical biological cargos to distal or neighboring recipient cells. On the other hand, their role in intercellular communication may also contribute to the pathogenesis of several diseases, including thrombosis. More recently, their physiological and biochemical properties have suggested their use as a therapeutic tool in tissue regeneration as well as a novel option for drug delivery. In this review, we will summarize the impact of EVs released from blood and vascular cells in arterial and venous thrombosis, describing the mechanisms by which EVs affect thrombosis and their potential clinical applications.

Biodiversity of foliar fungal endophytes in white spruce (Picea glauca) from southern Québec

2006 ◽  
Vol 84 (5) ◽  
pp. 777-790 ◽  
Author(s):  
F.O.P. Stefani ◽  
J.A. Bérubé
Keyword(s):  
Picea Glauca ◽  
Sequence Similarity ◽  
Fungal Endophytes ◽  
Biological Significance ◽  
Its Region ◽  
White Spruce ◽  
Nuclear Ribosomal Dna ◽  
High Sequence Similarity ◽  
Forestry Practices ◽  
The Impact

The objective of this study was to investigate the foliar endophyte biodiversity of white spruce ( Picea glauca (Moench) Voss to establish a baseline for future comparative studies examining the impact of forestry practices. It identifies for the first time endophytic fungi living inside the needles of white spruce from 280 needles collected in seven natural stands in southern Québec. The endophyte colonization rate on surface sterilized needles was 53.2%. We performed a PCR-RFLP and sequence analysis on the ITS region of the nuclear ribosomal DNA to achieve molecular identification. Isolate ITS sequences were compared with data from GenBank presenting the best similarity and were analyzed by a maximum of parsimony and Bayesian inference. Relationships between morphological groups, digestion groups, and sequence groups were investigated. In all, 23 morphotypes were found to belong to 14 sequence groups and we demonstrated that morphological groups are poor indicators for estimating species diversity. This study is the first to establish species richness values for foliar endophytes. Among the 141 isolates in this study, 75.15% have a high sequence similarity with Lophodermium piceae , 10.95% with an unknown species of Mycosphaerella , and 5.5% with two species of the genus Hypoxylon . Distribution, incidence and biological significance of all the endophytes found in this study are discussed.

scholarly journals Porsild spruce in Canada

2013 ◽  
Vol 89 (01) ◽  
pp. 24-31 ◽  
Author(s):  
Rodney Arthur Savidge
Keyword(s):  
United States ◽  
North America ◽  
Picea Glauca ◽  
Full Range ◽  
White Spruce ◽  
The United States ◽  
Atlantic Canada ◽  
Natural Range ◽  
Northwestern North America

The natural range of Porsild spruce (Picea glauca var. porsildii Raup), a white spruce variety distinguished by its smooth bark and resin blisters, has long been considered to be restricted to northwestern North America, but here it is noted that the same phenotype exists in wild stands in Ontario, Quebec, and Atlantic Canada. No record of Porsild spruce trees yet exists in the region between Alberta and western Ontario, or anywhere in the United States other than Alaska. The forestry community is requested to document any encounters with Porsild spruce in unmanaged stands, in order that its full range can be established. History and potential scientific importance of Porsild spruce are given consideration.

scholarly journals Avian Predation in a Declining Outbreak Population of the Spruce Budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae)

Insects ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 720
Author(s):  
Jacques Régnière ◽  
Lisa Venier ◽  
Dan Welsh
Keyword(s):  
Foraging Behavior ◽  
Picea Glauca ◽  
Choristoneura Fumiferana ◽  
Feeding Activity ◽  
Abies Balsamea ◽  
Bird Species ◽  
Spruce Budworm ◽  
White Spruce ◽  
Avian Predation ◽  
The Impact

The impact of avian predation on a declining population of the spruce budworm, Choristoneura fumifereana (Clem.), was measured using single-tree exclosure cages in a mature stand of balsam fir, Abies balsamea (L.), and white spruce, Picea glauca (Moench.) Voss. Bird population censuses and observations of foraging and nest-feeding activity were also made to determine the response of budworm-linked warblers to decreasing food availability. Seasonal patterns of foraging. as well as foraging success in the declining prey population was compared to similar information from birds observed in another stand where the spruce budworm population was rising. Avian predation was an important source of mortality between the 4th instar and moth emergence in the declining outbreak population. Mortality by predation increased from negligible to over 98% as budworm density dropped from 100 to <1 larva/kg of host foliage, over 3 years. Calculations based on nest-feeding activity and basic metabolic demands support these observed rates. Seasonal and yearly differences in predation rates observed between the two host-tree species correspond to equivalent shifts in bird foraging behavior in response to dropping insect density. In particular, a preference for searching on white spruce disappeared, although budworm-linked birds remained more efficient at finding food on this plant. The ability to change foraging behavior as prey density dropped differed between bird species.

Exponential fertilization and plant competition effects on the growth and N nutrition of trembling aspen and white spruce seedlings

2015 ◽  
Vol 45 (1) ◽  
pp. 78-86 ◽  
Author(s):  
Ya-Lin Hu ◽  
Yue Hu ◽  
De-Hui Zeng ◽  
Xiao Tan ◽  
Scott X. Chang
Keyword(s):  
Growth Performance ◽  
Populus Tremuloides ◽  
Picea Glauca ◽  
N Uptake ◽  
White Spruce ◽  
Trembling Aspen ◽  
N Nutrition ◽  
Nursery Production ◽  
Exponential Fertilization ◽  
The Impact

Exponential fertilization has been shown to be a useful technique for improving seedling quality during nursery production. In this study, we evaluated (i) the impact of exponential vs. conventional fertilization on trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench) Voss) seedlings during nursery production and (ii) the growth performance and nitrogen (N) utilization of those seedlings in response to foxtail barley (Hordeum jubatum L.) competition after the transplantation of seedlings in a greenhouse experiment. Exponential fertilization with an application rate higher than the conventional fertilization increased the internal N reserve in trembling aspen and white spruce seedlings during nursery production and also increased new leaf, new stem, and old stem biomass and N retranslocation rates in trembling aspen seedlings but not in white spruce seedlings after transplantation. Foxtail barley competition decreased N concentrations in seedlings and soil N uptake by the seedlings; however, increased N retranslocation rates with foxtail barley competition were observed in white spruce seedlings but not in trembling aspen seedlings. Our results suggest that the growth performance of seedlings was improved by N loading, whereas the impact of vegetation management was species specific.

Impact of eastern dwarf mistletoe (Arceuthobium pusillum) on host white spruce (Picea glauca) development, growth and performance across multiple scales

2012 ◽  
Vol 147 (4) ◽  
pp. 502-513 ◽  
Author(s):  
Barry A. Logan ◽  
Jaret S. Reblin ◽  
David M. Zonana ◽  
Ryan F. Dunlavey ◽  
Carolyn R. Hricko ◽  
...  
Keyword(s):  
Picea Glauca ◽  
Multiple Scales ◽  
White Spruce ◽  
Dwarf Mistletoe ◽  
And Performance

scholarly journals Birch (Betula papyrifera) × white spruce (Picea glauca) interactions in mixedwood stands: implications for management

2013 ◽  
Vol 59 (No. 4) ◽  
pp. 137-149 ◽  
Author(s):  
Ch.D.B. Hawkins ◽  
A. Dhar
Keyword(s):  
Regression Analysis ◽  
Picea Glauca ◽  
Mixed Model ◽  
Basal Area ◽  
White Spruce ◽  
Betula Papyrifera ◽  
Vegetation Control ◽  
Mixed Model Anova ◽  
Paper Birch ◽  
The Impact

Current British Columbia forest regulations drive the regeneration management towards pure conifer stands rather than remaining in a mixed-species condition. This approach may result in unnecessary vegetation control. The main objective of this investigation was to study the impact of variable paper birch densities on white spruce growth in 15&ndash;20 years old stands for management implications. Regression analysis was used to examine the effect of birch density and two competition indices to predict spruce growth. A mixed model ANOVA showed that spruce mean annual DBH and basal area increment differed significantly among sites and density. From the regression analysis it appears that birch density up to 4,000 stems&middot;ha<sup>&ndash;1</sup> had no significant influence on spruce growth which is much higher than the current BC reforestation guideline (1,000 stems&middot;ha<sup>&ndash;1</sup> broadleaves). Similarly, birch relative density index (RDI) had to exceed 3 to affect spruce DBH growth significantly on all sites except one. On most sites, spruce had a larger DBH than birch. Our results also suggest that rather than following the current broadcast approach to vegetation management, a targeted approach could enhance forest productivity and stand diversity. &nbsp;

scholarly journals Evaluating the impact of stand composition and competition on white spruce and aspen wood attributes in the boreal mixedwood

2021 ◽  
Author(s):  
◽  
Ryan Jackalin
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Wood Quality ◽  
White Spruce ◽  
Aspen Wood ◽  
Mixed Stands ◽  
Spruce Wood ◽  
Intimate Mixture ◽  
Volume Production ◽  
The Impact

I evaluated how intra- and inter-specific competition affects the development of eleven wood attributes of trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench) Voss) over 34 years. My analysis was conducted in a mixedwood trial site in Northern British Columbia, Canada, that included treatments consisting of 0, 1000, 2000, 5000, and 10000 stems per hectare of aspen. Competition was found to negatively influence wood attribute development in aspen and positively impact spruce (at low levels of competition). Plot level competition indices were the best predictor of variation in aspen wood attributes, while stand level competition (population density) best explained the majority of spruce wood attributes. Maintaining aspen at lower densities in intimate mixture can have a positive effect on spruce wood quality, while incurring relatively small reductions in spruce volume production and also retaining the ecological benefits associated with managing for mixed stands.

Impact of dwarf mistletoe on the growth of western hemlock trees having different patterns of suppression and release

1985 ◽  
Vol 15 (4) ◽  
pp. 665-668 ◽  
Author(s):  
A. J. Thomson ◽  
R. I. Alfaro ◽  
W. J. Bloomberg ◽  
R. B. Smith
Keyword(s):  
Volume Growth ◽  
Severe Infection ◽  
Vancouver Island ◽  
Western Hemlock ◽  
Dwarf Mistletoe ◽  
Area Sampling ◽  
The Impact ◽  
Site Variability

The impact of dwarf mistletoe on the volume growth of western hemlock was evaluated in trees from five locations on northeast Vancouver Island. Within each area, sampling was designed to minimize the effects of site variability. However, differences in age and in patterns of suppression and release between infection classes were observed in some stands. Growth was corrected for these differences by subtracting the suppression core and by making comparisons at equivalent ages. Volume losses associated with dwarf mistletoe infection were higher than reported in our previous studies in other areas, averaging 23 and 39% with moderate and severe infection levels, respectively.

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