scholarly journals Variation in white spruce needle respiration across the species range

2021 ◽  
Author(s):  
Kevin L Griffin ◽  
Zoe M. Griffin ◽  
Stephanie C Schmiege ◽  
Sarah G Bruner ◽  
Natalie T. Boelman ◽  
...  
Keyword(s):  
Picea Glauca ◽  
Dark Respiration ◽  
Temperature Response ◽  
White Spruce ◽  
Respiratory Physiology ◽  
Maximum Temperature ◽  
Published Data ◽  
Model Parameters ◽  
Range Limit ◽  
Temperate Trees

White spruce (Picea glauca) spans a massive range from arctic treeline to temperate forests. Yet the variability in respiratory physiology and the implications for tree carbon balance at the extremes of this distribution remain enigmasWorking at Arctic and Temperate sites more than 5000 km apart, we measured the short-term temperature response of dark respiration (R/T) at upper and lower canopy positions. R/T curves were fit to a polynomial model and model parameters (a, b, and c) were compared between locations, canopy positions, or with published data. Respiration measured at 25°C (R25) was 68% lower at the southern location than the northern location, resulting in a significantly lower a parameter of the R/T response in temperate trees Only at the southern location did upper canopy leaves have a steeper temperature response than lower canopy leaves, likely reflecting steeper canopy gradients in light. No differences were manifest in the maximum temperature of respiration. At the northern range limit, respiration appears extreme. This high carbon cost likely contributes to the current location of northern treeline. We find that respiration will increase with end-of-the-century warming and will likely continue to constrain the future range limits of this important boreal species.

The temperature response of leaf dark respiration in 15 provenances of Eucalyptus grandis grown in ambient and elevated CO2

2017 ◽  
Vol 44 (11) ◽  
pp. 1075 ◽  
Author(s):  
Michael J. Aspinwall ◽  
Vinod K. Jacob ◽  
Chris J. Blackman ◽  
Renee A. Smith ◽  
Mark G. Tjoelker ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
Tree Species ◽  
Unit Area ◽  
Dark Respiration ◽  
Eucalyptus Grandis ◽  
Temperature Response ◽  
Respiratory Physiology ◽  
Interactive Effects ◽  
Short Term ◽  
Leaf Dark Respiration

The effects of elevated CO2 on the short-term temperature response of leaf dark respiration (R) remain uncertain for many forest tree species. Likewise, variation in leaf R among populations within tree species and potential interactive effects of elevated CO2 are poorly understood. We addressed these uncertainties by measuring the short-term temperature response of leaf R in 15 provenances of Eucalyptus grandis W. Hill ex Maiden from contrasting thermal environments grown under ambient [CO2] (aCO2; 400 µmol mol–1) and elevated [CO2] (640 µmol mol–1; eCO2). Leaf R per unit area (Rarea) measured across a range of temperatures was higher in trees grown in eCO2 and varied up to 104% among provenances. However, eCO2 increased leaf dry mass per unit area (LMA) by 21%, and when R was expressed on a mass basis (i.e. Rmass), it did not differ between CO2 treatments. Likewise, accounting for differences in LMA among provenances, Rmass did not differ among provenances. The temperature sensitivity of R (i.e. Q10) did not differ between CO2 treatments or among provenances. We conclude that eCO2 had no direct effect on the temperature response of R in E. grandis, and respiratory physiology was similar among provenances of E. grandis regardless of home-climate temperature conditions.

scholarly journals High Leaf Respiration Rates May Limit the Success of White Spruce Saplings Growing in the Kampfzone at the Arctic Treeline

2021 ◽  
Vol 12 ◽  
Author(s):  
Kevin L. Griffin ◽  
Stephanie C. Schmiege ◽  
Sarah G. Bruner ◽  
Natalie T. Boelman ◽  
Lee A. Vierling ◽  
...  
Keyword(s):  
Picea Glauca ◽  
Temperature Response ◽  
White Spruce ◽  
The Arctic ◽  
Leaf Respiration ◽  
Respiration Rates ◽  
Canopy Position ◽  
Arctic Treeline ◽  
Biological Environment ◽  
The Relationship

Arctic Treeline is the transition from the boreal forest to the treeless tundra and may be determined by growing season temperatures. The physiological mechanisms involved in determining the relationship between the physical and biological environment and the location of treeline are not fully understood. In Northern Alaska, we studied the relationship between temperature and leaf respiration in 36 white spruce (Picea glauca) trees, sampling both the upper and lower canopy, to test two research hypotheses. The first hypothesis is that upper canopy leaves, which are more directly coupled to the atmosphere, will experience more challenging environmental conditions and thus have higher respiration rates to facilitate metabolic function. The second hypothesis is that saplings [stems that are 5–10cm DBH (diameter at breast height)] will have higher respiration rates than trees (stems ≥10cm DBH) since saplings represent the transition from seedlings growing in the more favorable aerodynamic boundary layer, to trees which are fully coupled to the atmosphere but of sufficient size to persist. Respiration did not change with canopy position, however respiration at 25°C was 42% higher in saplings compared to trees (3.43±0.19 vs. 2.41±0.14μmolm−2 s−1). Furthermore, there were significant differences in the temperature response of respiration, and seedlings reached their maximum respiration rates at 59°C, more than two degrees higher than trees. Our results demonstrate that the respiratory characteristics of white spruce saplings at treeline impose a significant carbon cost that may contribute to their lack of perseverance beyond treeline. In the absence of thermal acclimation, the rate of leaf respiration could increase by 57% by the end of the century, posing further challenges to the ecology of this massive ecotone.

Acclimation to light in planted and naturally regenerated populations of white spruce seedlings

2000 ◽  
Vol 78 (12) ◽  
pp. 1495-1504 ◽  
Author(s):  
Tala Awada ◽  
Robert E Redmann
Keyword(s):  
Picea Glauca ◽  
Dark Respiration ◽  
Seedling Survival ◽  
Physiological Responses ◽  
White Spruce ◽  
Population Variation ◽  
Light Acclimation ◽  
Photosynthetic Rates ◽  
Intrapopulation Variation ◽  
Sun And Shade

Physiological responses to sun and shade were examined in white spruce (Picea glauca (Moench) Voss) seedlings collected from three naturally regenerated (N1-N3) and three planted (P1-P3) stands in the boreal forest of Saskatchewan. Seedling survival was greater in the sun than in the shade pretreatment periods. Dark respiration declined by 70% in shade- compared with sun-acclimated seedlings; however, the decline was not statistically significant because of the large within-population variation. Quantum yield, total chlorophyll content, specific leaf area, and absolute water content of needles increased by 45, 33, 32, and 50%, respectively, in response to shade. At low light levels, shade-acclimated populations showed greater photosynthetic rates and steeper light-response curves than seedlings growing in full sun. Seedlings of P3, N2. and N3 saturated at about 200 µmol·m-2·s-1 PAR in the shade, with no increase in photosynthesis at higher light intensities. At light saturation, populations P1 and N3 showed similar photosynthetic rates to both light acclimation regimes; populations P2, P3, and N2 had lower light-saturated photosynthesis in sun, compared with shade pretreatment. Only in N1 was photosynthetic rate greater after sun than shade pretreatment; this population behaved like a "sun" and "shade" population depending on pretreatment. Differences in physiological responses to light among populations suggest the presence of more than one ecotype. N1 showed the greatest plasticity in response to light pretreatment. The remaining populations behaved more like shade-adapted populations, with little adjustment to light conditions. Intrapopulation variation was large for both regeneration types. It appears that selection pressure during reforestation was not great enough to cause a decline in intrapopulation variation in planted compared with naturally regenerated white spruce seedlings.Key words: Picea glauca, white spruce, light acclimation, photosynthesis.

scholarly journals High Leaf Respiration Rates May Limit the Success of White Spruce Saplings growing in The Kampfzone at the Arctic Treeline

2021 ◽  
Author(s):  
Kevin L Griffin ◽  
Stephanie C Schmeige ◽  
Sarah G Bruner ◽  
Natalie T Boelman ◽  
Lee A Vierling ◽  
...  
Keyword(s):  
Picea Glauca ◽  
Alternative Hypothesis ◽  
Temperature Response ◽  
White Spruce ◽  
The Arctic ◽  
Leaf Respiration ◽  
Respiration Rates ◽  
Canopy Position ◽  
Arctic Treeline ◽  
The Relationship

Arctic Treeline is the transition from the boreal forest to the treeless tundra and may be determined by growing season temperatures. The physiological mechanisms involved in determining the relationship between the physical and biological environment and the location of treeline are not fully understood. In Northern Alaska we studied the relationship between temperature and leaf respiration in 36 white spruce (Picea glauca) trees, sampling both the upper and lower canopy, to test two research hypotheses (H0). The first H01 is that canopy position will not influence leaf respiration. The associated alternative hypothesis (HA) is that the upper canopy leaves which are more directly coupled to the atmosphere will experience more challenging environmental conditions and thus have higher respiration rates to facilitate metabolic function. The second H02 is that tree size will not influence leaf respiration. The associated HA is that saplings (stems that are 5-10 cm DBH (diameter at breast height)) will have higher respiration rates than trees (stems ≥ 10 cm DBH) since saplings represent the transition from seedlings growing in the more favorable aerodynamic boundary layer, to trees which are fully coupled to the atmosphere but of sufficient size to persist. Respiration did not change with canopy position, however respiration at 25°C was 42% higher in saplings compared to trees (3.43 ± 0.19 vs. 2.41 ± 0.14 μmol m-2s-1). Furthermore, there were significant differences in the temperature response of respiration, and seedlings reached their maximum respiration rates at 59°C, more than two degrees higher than trees. Our results demonstrate that the respiratory characteristics of white spruce saplings at treeline are extreme, imposing a significant carbon cost that may contribute to their lack of perseverance beyond treeline. In the absence of thermal acclimation, the rate of leaf respiration could increase by 57% by the end of the century, posing further challenges to the ecology of this massive ecotone.

scholarly journals New Mathematical Modeling Approach for Predicting Microbial Inactivation by High Hydrostatic Pressure

2007 ◽  
Vol 73 (8) ◽  
pp. 2468-2478 ◽  
Author(s):  
Bernadette Klotz ◽  
D. Leo Pyle ◽  
Bernard M. Mackey
Keyword(s):  
Microbial Inactivation ◽  
Inactivation Kinetics ◽  
Published Data ◽  
Model Parameters ◽  
Order Kinetic ◽  
Square Root ◽  
Additional Time ◽  
Decimal Reduction Time ◽  
First Order ◽  
Primary Model

ABSTRACT A new primary model based on a thermodynamically consistent first-order kinetic approach was constructed to describe non-log-linear inactivation kinetics of pressure-treated bacteria. The model assumes a first-order process in which the specific inactivation rate changes inversely with the square root of time. The model gave reasonable fits to experimental data over six to seven orders of magnitude. It was also tested on 138 published data sets and provided good fits in about 70% of cases in which the shape of the curve followed the typical convex upward form. In the remainder of published examples, curves contained additional shoulder regions or extended tail regions. Curves with shoulders could be accommodated by including an additional time delay parameter and curves with tails shoulders could be accommodated by omitting points in the tail beyond the point at which survival levels remained more or less constant. The model parameters varied regularly with pressure, which may reflect a genuine mechanistic basis for the model. This property also allowed the calculation of (a) parameters analogous to the decimal reduction time D and z, the temperature increase needed to change the D value by a factor of 10, in thermal processing, and hence the processing conditions needed to attain a desired level of inactivation; and (b) the apparent thermodynamic volumes of activation associated with the lethal events. The hypothesis that inactivation rates changed as a function of the square root of time would be consistent with a diffusion-limited process.

WHITE SPRUCE AND THE SPRUCE BUDWORM: DEFINING THE PHENOLOGICAL WINDOW OF SUSCEPTIBILITY

1997 ◽  
Vol 129 (2) ◽  
pp. 291-318 ◽  
Author(s):  
Robert K. Lawrence ◽  
William J. Mattson ◽  
Robert A. Haack
Keyword(s):  
Picea Glauca ◽  
High Performance ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
White Spruce ◽  
Shoot Elongation ◽  
Larval Survival ◽  
Strongly Correlated ◽  
Negative Effect ◽  
Foliar Traits

AbstractSynchrony of insect and host tree phenologies has often been suggested as an important factor influencing the susceptibility of white spruce, Picea glauca (Moench) Voss, and other hosts to the spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae). We evaluated this hypothesis by caging several cohorts of spruce budworm larvae on three white spruce populations at different phenological stages of the host trees, and then comparing budworm performance with host phenology and variation of 13 foliar traits. The beginning of the phenological window of susceptibility in white spruce occurs several weeks prior to budbreak, and the end of the window is sharply defined by the end of shoot growth. Performance was high for the earliest budworm cohorts that we tested. These larvae began feeding 3–4 weeks prior to budbreak and completed their larval development prior to the end of shoot elongation. Optimal synchrony occurred when emergence preceded budbreak by about 2 weeks. Larval survival was greater than 60% for individuals starting development 1–3 weeks prior to budbreak, but decreased to less than 10% for those starting development 2 or more weeks after budbreak and thus completing development after shoot elongation ceased. High performance by the budworm was most strongly correlated with high levels of foliar nitrogen, phosphorous, potassium, copper, sugars, and water and low levels of foliar calcium, phenolics, and toughness. These results suggest that advancing the usual phenological window of white spruce (i.e. advancing budbreak prior to larval emergence) or retarding budworm phenology can have a large negative effect on the spruce budworm’s population dynamics.

A new endoconidial black meristematic genus, Atramixtia, associated with declining white spruce and phylogenetically allied to a lineage of dothidealean conifer pathogens

Botany ◽  
2011 ◽  
Vol 89 (5) ◽  
pp. 323-338 ◽  
Author(s):  
A. Tsuneda ◽  
M.L. Davey ◽  
R.S. Currah
Keyword(s):  
Plant Tissue ◽  
Picea Glauca ◽  
White Spruce ◽  
Natural Substrate ◽  
Dividing Cells ◽  
Granular Matrix ◽  
Phylogenetic Affinities

An endoconidial, black meristematic taxon Atramixtia arboricola gen. et. sp. nov. (Dothideales) from the black subicula found on twigs of declining white spruce, Picea glauca (Moench) Voss, in Alberta is described. It is morphologically distinguishable from other endoconidial taxa by the conidioma composed of clumps of endoconidial conidiogenous cells, scattered meristematically dividing cells, dematiaceous hyphae, abundant brown, granular matrix materials, and sometimes plant tissue. Endoconidia also occur in conidiogenous cellular clumps that are not organized into a conidioma but develop directly from stromatic cells on the bark. In culture, it forms similar endoconidial conidiomata and also a mycelial, blastic synanamorph that superficially resembles Hormonema . Atramixtia arboricola is a member of the Dothideales and shows phylogenetic affinities to a clade of conifer-stem and -needle pathogens, including Sydowia and Delphinella , although no teleomorph was found either on the natural substrate or in culture. It has not been determined whether A. arboricola is pathogenic to its host, but the occurrence of abundant intracellular hyphae in the host periderm suggests that the fungus is at least parasitic.

Soil carbon sequestration with forest expansion in an arctic forest–tundra landscape

2004 ◽  
Vol 34 (7) ◽  
pp. 1538-1542 ◽  
Author(s):  
Heidi Steltzer
Keyword(s):  
Soil Carbon ◽  
Picea Glauca ◽  
White Spruce ◽  
Tree Age ◽  
Forest Expansion ◽  
Soil C ◽  
C Storage ◽  
C Pools ◽  
Sampling Locations

Soil carbon (C) and nitrogen (N) pools were measured under the canopy of 29 white spruce (Picea glauca (Moench) Voss) trees and in the surrounding tundra 3 and 6 m away from each tree at three sites of recent forest expansion along the Agashashok River in northwestern Alaska. The aim was to characterize the potential for forest expansion to lead to increased soil C pools across diverse tundra types. Soil C beneath the trees correlated positively with tree age, suggesting that tree establishment has led to C storage in the soils under their canopy at a rate of 18.5 ± 4.6 g C·m–2·year–1. Soil C in the surrounding tundra did not differ from those under the trees and showed no relationship to tree age. This characterization of the soil C pools at the 3-m scale strengthens the assertion that the pattern associated with the trees is an effect of the trees, because tree age cannot explain variation among tundra sampling locations at this scale. Potential mechanisms by which these white spruce trees could increase soil C pools include greater production and lower litter quality.

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