Vulnerability of white spruce tree growth in interior Alaska in response to climate variability: dendrochronological, demographic, and experimental perspectivesThis article is one of a selection of papers from The Dynamics of Change in Alaska’s Boreal Forests: Resilience and Vulnerability in Response to Climate Warming.

2010 ◽  
Vol 40 (7) ◽  
pp. 1197-1209 ◽  
Author(s):  
A. David McGuire ◽  
Roger W. Ruess ◽  
A. Lloyd ◽  
J. Yarie ◽  
Joy S. Clein ◽  
...  
Keyword(s):  
Climate Warming ◽  
Tree Growth ◽  
Picea Glauca ◽  
Boreal Forests ◽  
Climatic Variability ◽  
White Spruce ◽  
Interior Alaska ◽  
Soil Moisture Availability ◽  
Plant Water Balance ◽  
Selection Of

This paper integrates dendrochronological, demographic, and experimental perspectives to improve understanding of the response of white spruce ( Picea glauca (Moench) Voss) tree growth to climatic variability in interior Alaska. The dendrochronological analyses indicate that climate warming has led to widespread declines in white spruce growth throughout interior Alaska that have become more prevalent during the 20th century. Similarly, demographic studies show that white spruce tree growth is substantially limited by soil moisture availability in both mid- and late-successional stands. Interannual variability in tree growth among stands within a landscape exhibits greater synchrony than does growth of trees that occupy different landscapes, which agrees with dendrochronological findings that the responses depend on landscape position and prevailing climate. In contrast, the results from 18 years of a summer moisture limitation experiment showed that growth in midsuccessional upland stands was unaffected by moisture limitation and that moisture limitation decreased white spruce growth in floodplain stands where it was expected that growth would be less vulnerable because of tree access to river water. Taken together, the evidence from the different perspectives analyzed in this study clearly indicates that white spruce tree growth in interior Alaska is vulnerable to the effects of warming on plant water balance.

Nonlinear responses of white spruce growth to climate variability in interior Alaska

2013 ◽  
Vol 43 (4) ◽  
pp. 331-343 ◽  
Author(s):  
Andrea H. Lloyd ◽  
Paul A. Duffy ◽  
Daniel H. Mann
Keyword(s):  
Picea Glauca ◽  
Boreal Forests ◽  
General Circulation ◽  
Circulation Model ◽  
White Spruce ◽  
Climatic Conditions ◽  
Boosted Regression Trees ◽  
Temperature And Precipitation ◽  
Interior Alaska ◽  
And Function

Ongoing warming at high latitudes is expected to lead to large changes in the structure and function of boreal forests. Our objective in this research is to determine the climatic controls over the growth of white spruce (Picea glauca (Moench) Voss) at the warmest driest margins of its range in interior Alaska. We then use those relationships to determine the climate variables most likely to limit future growth. We collected tree cores from white spruce trees growing on steep, south-facing river bluffs at five sites in interior Alaska, and analyzed the relationship between ring widths and climate using boosted regression trees. Precipitation and temperature of the previous growing season are important controls over growth at most sites: trees grow best in the coolest, wettest years. We identify clear thresholds in growth response to a number of variables, including both temperature and precipitation variables. General circulation model (GCM) projections of future climate in this region suggest that optimum climatic conditions for white spruce growth will become increasingly rare in the future. This is likely to cause short-term declines in productivity and, over the longer term, probably lead to a contraction of white spruce to the cooler, moister parts of its range in Alaska.

scholarly journals White spruce growth sensitivity to climate variability in pure and mixedwood stands

2020 ◽  
Author(s):  
◽  
Jéssica Chaves Cardoso
Keyword(s):  
Climate Variability ◽  
Tree Growth ◽  
Sap Flow ◽  
Picea Glauca ◽  
Boreal Forests ◽  
White Spruce ◽  
Climate Variables ◽  
Composition And Structure ◽  
Microclimate Variables ◽  
Mixedwood Stands

It is prudent to understand how tree growth responds to climate variability to better project their growth in the current and future changes in climate in boreal forests. In this thesis, I studied how climate variables influence individual white spruce trees (Picea glauca (Moench) Voss) over short and intermediate periods in pure and mixedwood stands in northeastern British Columbia. In Chapter 2, I studied the importance and the influence of annual, seasonal, and monthly microclimate variables on the annual growth of white spruce trees in pure and mixedwood stands. In Chapter 3, I studied the importance and the influence of microclimate variables on sap flow of white spruce trees through different time scales in these two stand types. My key finding in these two chapters is that stand composition and structure are essential determinants of how spruce radial growth and sap flow respond to fluctuations in climate variables, and how they will respond to projected future climate scenarios. A combination of warmer temperatures and drought during summer will negatively affect white spruce trees growth in pure and mixedwood stands in the studied region. Spruce sap flow in both stand types is likely to increase as the climate warms, increasing the demand for soil water. As this resource becomes less available, white spruce in both stand types are likely to respond with processes that can compromise their physiological integrity. White spruce growing in mixedwood stands might be more sensitive to drought stress than in pure stands due to the higher competition for limiting resources (primarily water). This thesis provides information of expected changes in tree growth to climate variability and demonstrates the importance of appropriate site selection to plant spruce trees and management of pure and mixedwood stands.

A 200-Year Perspective of Climate Variability and the Response of White Spruce in Interior Alaska

2003 ◽  
Author(s):  
Glenn Patrick Juday ◽  
Valerie Barber
Keyword(s):  
Nineteenth Century ◽  
North America ◽  
Climate Variability ◽  
Tree Ring ◽  
Tree Growth ◽  
White Spruce ◽  
Boreal Region ◽  
The North ◽  
Interior Alaska ◽  
Summer Temperatures

The two most important life functions that organisms carry out to persist in the environment are reproduction and growth. In this chapter we examine the role of climate and climate variability as controlling factors in the growth of one of the most important and productive of the North American boreal forest tree species, white spruce (Picea glauca [Moench] Voss). Because the relationship between climate and tree growth is so close, tree-ring properties have been used successfully for many years as a proxy to reconstruct past climates. Our recent reconstruction of nineteenth- century summer temperatures at Fairbanks based on white spruce tree-ring characteristics (Barber et al. in press) reveals a fundamental pattern of quasi-decadal climate variability. The values in this reconstruction of nineteenth-century Fairbanks summer temperatures are surprisingly warm compared to values in much of the published paleoclimatic literature for boreal North America. In this chapter we compare our temperature reconstructions with ring-width records in northern and south-central Alaska to see whether tree-growth signals in the nineteenth century in those regions are consistent with tree-ring characteristics in and near Bonanza Creek (BNZ) LTER (25 km southwest of Fairbanks) that suggest warm temperatures during the mid-nineteenth century. We also present a conceptual model of key limiting events in white spruce reproduction and compare it to a 39-year record of seed fall at BNZ. Finally, we derive a radial growth pattern index from white spruce at nine stands across Interior Alaska that matches recent major seed crop events in the BNZ monitoring period, and we identify dates after 1800 when major seed crops of white spruce, which are infrequent, may have been produced. The boreal region is characterized by a broad zone of forest with a continuous distribution across Eurasia and North America, amounting to about 17% of the earth’s land surface area (Bonan et al. 1992). The boreal region is often conceived of as a zone of relatively homogenous climate, but in fact a surprising diversity of climates are present. During the long days of summer, continental interior locations under persistent high-pressure systems experience hot weather that can promote extensive forest fires frequently exceeding 100 kilohectares (K ha). Summer daily maximum temperatures are cooled to a considerable degree in maritime portions of the boreal region affected by air masses that originate over the North Atlantic, North Pacific, or Arctic Oceans.

Consistent negative temperature sensitivity and positive influence of precipitation on growth of floodplain Picea glauca in Interior Alaska

2012 ◽  
Vol 42 (3) ◽  
pp. 561-573 ◽  
Author(s):  
Glenn Patrick Juday ◽  
Claire Alix
Keyword(s):  
Picea Glauca ◽  
Negative Relationship ◽  
Ring Width ◽  
Negative Temperature ◽  
White Spruce ◽  
Positive Influence ◽  
Monthly Precipitation ◽  
Temperature And Precipitation ◽  
Interior Alaska ◽  
Common Signal

This paper calibrates climate controls over radial growth of floodplain white spruce ( Picea glauca (Moench) Voss) and examines whether growth in these populations responds similarly to climate as upland trees in Interior Alaska. Floodplain white spruce trees hold previously unrecognized potential for long-term climate reconstruction because they are the source of driftwood that becomes frozen in coastal deposits, where archeological timbers and beach logs represent well-preserved datable material. We compared ring width chronologies for 135 trees in six stands on the Yukon Flats and Tanana River with temperature and precipitation at Fairbanks from 1912–2001. Our sample contains a stable common signal representing a strong negative relationship between summer temperature and tree growth. We developed a floodplain temperature index (FPTI), which explains half of the variability of the composite chronology, and a supplemental precipitation index (SPI) based on correlation of monthly precipitation with the residual of the temperature-based prediction of growth. We then combined FPTI and SPI into a climate favorability index (CFI) in which above-normal precipitation partially compensates for temperature-induced drought reduction of growth and vice versa. CFI and growth have been particularly low since 1969. Our results provide a basis for building longer chronologies based on archeological wood and for projecting future growth.

Regenerating white spruce, paper birch, and willow in south-central Alaska

1999 ◽  
Vol 29 (7) ◽  
pp. 993-1001 ◽  
Author(s):  
E C Cole ◽  
M Newton ◽  
A Youngblood
Keyword(s):  
Picea Glauca ◽  
Volume Growth ◽  
White Spruce ◽  
Site Preparation ◽  
Stem Volume ◽  
Dendroctonus Rufipennis ◽  
Relative Growth Rates ◽  
South Central ◽  
Interior Alaska ◽  
Paper Birch

The current spruce bark beetle (Dendroctonus rufipennis Kirby) epidemic in interior Alaska is leaving large expanses of dead spruce with little spruce regeneration. Many of these areas are habitat for moose (Alces alces). To establish spruce regeneration and improve browse production for moose, paper birch (Betula papyrifera Marsh), willow (Salix spp.), and three stocktypes (plug+1 bareroot, and 1+0 plugs from two nurseries) of white spruce (Picea glauca (Moench) Voss) were planted in freshly cutover areas on Fort Richardson, near Anchorage. Four vegetation-management treatments were compared: broadcast site preparation with herbicides, banded site preparation with herbicides, mechanical scarification, and untreated control. Spruce seedlings had the greatest growth in the broadcast site preparation treatment (p < 0.01). Stocktype was the most important factor in spruce growth, with bareroot transplant seedlings being the tallest and largest 5 years after planting (p < 0.001). In the first 3 years, relative stem volume growth was greater for plug seedlings than for bareroot seedlings (p < 0.001). By year 4, relative growth rates were similar among all stocktypes. Treatment effects for paper birch and willow were confounded by moose browsing. Results indicate spruce can be regenerated and moose browse enhanced simultaneously in forests in interior Alaska.

scholarly journals A partial deciduous canopy, coupled with site preparation, produces excellent growth of planted white spruce

2019 ◽  
Vol 49 (3) ◽  
pp. 270-280 ◽  
Author(s):  
Victor J. Lieffers ◽  
Derek Sidders ◽  
Tim Keddy ◽  
Kevin A. Solarik ◽  
Peter Blenis
Keyword(s):  
Picea Glauca ◽  
Boreal Forests ◽  
High Speed ◽  
White Spruce ◽  
Site Preparation ◽  
Stem Volume ◽  
Soil Mixing ◽  
Excellent Growth ◽  
Total Growth ◽  
Best Estimates

Survival and growth of planted white spruce (Picea glauca (Moench) Voss) were assessed at year 15 in boreal mixedwood stands of northern Alberta, Canada, in stands that were deciduous-dominated prior to logging or were conifer-dominated. Three overstory retention levels (0%, 50%, and 75% retention) and four site preparation treatments (mound, high speed mix, scalp, and no treatment) were evaluated. In deciduous-dominated stands, planted spruce performed best in the 50% retention; here, stem volume was at least double that of any other retention treatment after 15 years. In contrast, spruce had reduced growth in coniferous-dominated stands in both 50% and 75% retention treatments compared with the 0% retention. Survival of planted spruce was unaffected by level of retention, but survival was lower in coniferous-dominated stands than in deciduous-dominated stands; in the coniferous-dominated stands, survival was better with mounding and mixing and lowest with scalp treatments. All height variables tended to be greater in the mix and mound site preparation treatments. Finally, the best estimates of future total growth (regenerated spruce and deciduous combined) in the coniferous-dominated stands were in the clearcut treatment. In terms of regenerated spruce growth, the best estimates occurred in the deciduous-dominated – 50% retention stand planted with soil mixing–mounding treatments, where projected growth of spruce was comparable with that of open-grown and tended stands in Alberta’s boreal forests.

Regeneration alternatives for upland white spruce after burning and logging in interior Alaska

1999 ◽  
Vol 29 (4) ◽  
pp. 413-423 ◽  
Author(s):  
R V Densmore ◽  
G P Juday ◽  
J C Zasada
Keyword(s):  
Growth Rates ◽  
Picea Glauca ◽  
Natural Regeneration ◽  
White Spruce ◽  
Site Preparation ◽  
Seed Source ◽  
Positive Effects ◽  
Interior Alaska

Site-preparation and regeneration methods for white spruce (Picea glauca (Moench) Voss) were tested near Fairbanks, Alaska, on two upland sites which had been burned in a wildfire and salvage logged. After 5 and 10 years, white spruce regeneration did not differ among the four scarification methods but tended to be lower without scarification. Survival of container-grown planted seedlings stabilized after 3 years at 93% with scarification and at 76% without scarification. Broadcast seeding was also successful, with one or more seedlings on 80% of the scarified 6-m2 subplots and on 60% of the unscarified subplots after 12 years. Natural regeneration after 12 years exceeded expectations, with seedlings on 50% of the 6-m2 subplots 150 m from a seed source and on 28% of the subplots 230 m from a seed source. After 5 years, 37% of the scarified unsheltered seed spots and 52% of the scarified seed spots with cone shelters had one or more seedlings, but only 16% of the unscarified seed spots had seedlings, with and without funnel shelters. Growth rates for all seedlings were higher than on similar unburned sites. The results show positive effects of burning in interior Alaska, and suggest planting seedlings, broadcast seeding, and natural seedfall, alone or in combination, as viable options for similar sites.

CO2 stimulation and response mechanisms vary with light supply in boreal conifers

2020 ◽  
Author(s):  
Qing-Lai Dang ◽  
Jacob Marfo ◽  
Fengguo Du ◽  
Rongzhou Man ◽  
Sahari Inoue
Keyword(s):  
Elevated Co2 ◽  
Picea Glauca ◽  
Boreal Forests ◽  
Black Spruce ◽  
Net Photosynthesis ◽  
Growing Season ◽  
White Spruce ◽  
Light Supply ◽  
Ecophysiological Responses ◽  
Light Effects

Abstract Aims Black spruce (Picea mariana [Mill.] B.S.P.) and white spruce (Picea glauca [Moench] Voss.) are congeneric species. Both are moderately shade tolerant and widely distributed across North American boreal forests. Methods To understand light effects on their ecophysiological responses to elevated [CO2], 1-year old seedlings were exposed to 360 and 720 µmol mol -1 [CO2] at three light conditions (100, 50 and 30% of full light in the greenhouse). Foliar gas exchanges were measured in the mid- and late-growing season. Important Findings Elevated [CO2] increased net photosynthesis (Pn) and photosynthetic water use efficiency, but it reduced stomatal conductance and transpiration. The stimulation of photosynthesis by CO2 was greatest at 50% light and smallest at 100%. Photosynthesis, maximum carboxylation rate (Vcmax) and light saturated rate of electron transport (Jmax) all decreased with decreasing light. Elevated [CO2] significantly reduced Vcmax across all light treatments and both species in mid-growing season. However, the effect of elevated [CO2] became insignificant at 30% light later in the growing season, with the response being greater in black spruce than in white spruce. Elevated [CO2] also reduced Jmax in white spruce in both measurements while the effect became insignificant at 30% light later in the growing season. However, the effect on black spruce varied with time. Elevated [CO2] reduced Jmax in black spruce in mid-growing season in all light treatments and the effect became insignificant at 30% light later in the growing season, while it increased Jmax later in the season at 100% and 50% light. These results suggest that both species benefited from elevated CO2, and that the responses varied with light supply, such that the response was primarily physiological at 100% and 50% light, while it was primarily morphological at 30% light.

Climatic warming and its effect on bud burst and risk of frost damage to white spruce in Canada

1998 ◽  
Vol 74 (4) ◽  
pp. 567-577 ◽  
Author(s):  
Stephen J. Colombo
Keyword(s):  
Climate Warming ◽  
Picea Glauca ◽  
Global Climate ◽  
White Spruce ◽  
Frost Damage ◽  
Weather Data ◽  
Bud Burst ◽  
Freezing Damage ◽  
Local Climate ◽  
Frost Risk

Temperature data from ten weather stations across Canada were used to model the effects of climate warming on the timing of bud burst and the risk of frost damage to white spruce (Picea glauca (Moench) Voss). There was evidence of increasingly earlier dates of bud break over the course of this century at half of the stations examined (Amos and Brome, Québec; Cochrane, Ontario; Fort Vermilion, Alberta; and Woodstock, New Brunswick), with the period 1981 to 1988 having the earliest predicted dates of bud burst (earliest degree day accumulation). Risk of frost damage at most stations in the 1980s was usually greater than in earlier periods. Weather data modelled for climate warming of 5 °C predicts that bud burst will occur two to four weeks sooner than was the case during 1961 to 1980 at all stations, but that this will generally be accompanied by decreased risk of frost after bud burst. However, while the expected trend is one of reduced frost risk in the future, as the climate gradually warms frost risk is expected to fluctuate upward or downward depending on interactions between provenance and local climate. Key words: bud burst, climate warming, dormancy, freezing damage, frost, global climate change, Picea glauca, white spruce

Cold-hardiness of adult and larval spruce beetles Dendroctonus rufipennis (Kirby) in interior Alaska

1987 ◽  
Vol 65 (12) ◽  
pp. 2927-2930 ◽  
Author(s):  
L. Keith Miller ◽  
Richard A. Werner
Keyword(s):  
Picea Glauca ◽  
Cold Hardiness ◽  
Insect Pest ◽  
White Spruce ◽  
Dendroctonus Rufipennis ◽  
Interior Alaska

Dendroctonus rufipennis, a serious insect pest causing periodic widespread damage to mature white spruce (Picea glauca (Moench) Voss) stands in Alaska, was studied to determine if either larvae or adults were freezing-tolerant. Mean supercooling points in both larvae and adults dropped from −12 °C in summer to about −31 °C in winter. The decrease in supercooling points in larvae was closely associated with synthesis of glycerol, but the decline in adult supercooling points partially preceded the synthesis of glycerol in the fall. Winter glycerol levels reached 3 molal. Neither larvae nor adults were freezing-tolerant at any time of the year. Measurement of temperatures beneath the bark of standing spruce showed that only beetles hibernating below the snowline would be expected to survive a typical winter.

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