Resilience of Alaska’s boreal forest to climatic changeThis 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. 1360-1370 ◽  
Author(s):  
F.S. Chapin ◽  
A.D. McGuire ◽  
R.W. Ruess ◽  
T.N. Hollingsworth ◽  
M.C. Mack ◽  
...  
Keyword(s):  
Rural Communities ◽  
Boreal Forest ◽  
Climate Warming ◽  
Boreal Forests ◽  
Structural Changes ◽  
Winter Season ◽  
Indigenous Communities ◽  
Structural Features ◽  
Temperature Sensitive ◽  
The Impact

This paper assesses the resilience of Alaska’s boreal forest system to rapid climatic change. Recent warming is associated with reduced growth of dominant tree species, plant disease and insect outbreaks, warming and thawing of permafrost, drying of lakes, increased wildfire extent, increased postfire recruitment of deciduous trees, and reduced safety of hunters traveling on river ice. These changes have modified key structural features, feedbacks, and interactions in the boreal forest, including reduced effects of upland permafrost on regional hydrology, expansion of boreal forest into tundra, and amplification of climate warming because of reduced albedo (shorter winter season) and carbon release from wildfires. Other temperature-sensitive processes for which no trends have been detected include composition of plant and microbial communities, long-term landscape-scale change in carbon stocks, stream discharge, mammalian population dynamics, and river access and subsistence opportunities for rural indigenous communities. Projections of continued warming suggest that Alaska’s boreal forest will undergo significant functional and structural changes within the next few decades that are unprecedented in the last 6000 years. The impact of these social–ecological changes will depend in part on the extent of landscape reorganization between uplands and lowlands and on policies regulating subsistence opportunities for rural communities.

Wildlife-mitigated precommercial thinning maintains the abundance of fruit shrubs in a boreal forest

2013 ◽  
Vol 43 (3) ◽  
pp. 306-310 ◽  
Author(s):  
Mélanie Major ◽  
André Desrochers
Keyword(s):  
Species Composition ◽  
Boreal Forest ◽  
Boreal Forests ◽  
Late Summer ◽  
Diameter Growth ◽  
Precommercial Thinning ◽  
Wildlife Species ◽  
Abundance And Distribution ◽  
And Control ◽  
The Impact

In boreal forests, fruits are an abundant resource in late summer and benefit many wildlife species. Fruits are mainly found in early successional stands, which are often subject to precommercial thinning designed to increase diameter growth of residual trees and manage stand species composition. Concerns about the consequences of precommercial thinning on wildlife have led to various methods of precommercial thinning with mitigation for wildlife. In summers 2007 and 2008, we examined the impact of wildlife-mitigated thinning on fruit shrub abundance and distribution at the Forêt Montmorency, Quebec. The abundance of fruit shrubs of all species except Amelanchier was similar in thinned and control stands but was highly variable among individual stands. Amelanchier shrubs appeared to benefit from thinning, especially 10 to 20 years after clearcutting. Fruit shrubs were highly clustered within early successional stands, but less so after thinning. We conclude that wildlife-mitigated precommercial thinning does not reduce access to fruits for birds and other frugivores and may even facilitate it in eastern Canadian boreal forests.

scholarly journals Analysis of the Effect of Climate Warming on Paludification Processes: Will Soil Conditions Limit the Adaptation of Northern Boreal Forests to Climate Change? A Synthesis

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1176
Author(s):  
Ahmed Laamrani ◽  
Osvaldo Valeria ◽  
Abdelghani Chehbouni ◽  
Yves Bergeron
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Boreal Forest ◽  
Climate Warming ◽  
Boreal Forests ◽  
Extreme Weather Events ◽  
Soil Conditions ◽  
Climatic Warming ◽  
Forest Species ◽  
Peat Accumulation

Northern boreal forests are characterized by accumulation of accumulation of peat (e.g., known as paludification). The functioning of northern boreal forest species and their capacity to adapt to environmental changes appear to depend on soil conditions. Climate warming is expected to have particularly pronounced effects on paludified boreal ecosystems and can alter current forest species composition and adaptation by changing soil conditions such as moisture, temperature regimes, and soil respiration. In this paper, we review and synthesize results from various reported studies (i.e., 88 research articles cited hereafter) to assess the effects of climatic warming on soil conditions of paludified forests in North America. Predictions that global warming may increase the decomposition rate must be considered in combination with its impact on soil moisture, which appears to be a limiting factor. Local adaptation or acclimation to current climatic conditions is occurring in boreal forests, which is likely to be important for continued ecosystem stability in the context of climate change. The most commonly cited response of boreal forest species to global warming is a northward migration that tracks the climate and soil conditions (e.g., temperature and moisture) to which they are adapted. Yet, some constraints may influence this kind of adaptation, such as water availability, changes in fire regimes, decomposer adaptations, and the dynamic of peat accumulation. In this paper, as a study case, we examined an example of potential effects of climatic warming on future paludification changes in the eastern lowland region of Canada through three different combined hypothetical scenarios based on temperature and precipitation (e.g., unchanged, increase, or decrease). An increase scenario in precipitation will likely favor peat accumulation in boreal forest stands prone to paludification and facilitate forested peatland expansion into upland forest, while decreased or unchanged precipitation combined with an increase in temperature will probably favor succession of forested peatlands to upland boreal forests. Each of the three scenarios were discussed in this study, and consequent silvicultural treatment options were suggested for each scenario to cope with anticipated soil and species changes in the boreal forests. We concluded that, despite the fact boreal soils will not constrain adaptation of boreal forests, some consequences of climatic warming may reduce the ability of certain species to respond to natural disturbances such as pest and disease outbreaks, and extreme weather events.

scholarly journals The Dynamics of Transpiration to Evapotranspiration Ratio under Wet and Dry Canopy Conditions in a Humid Boreal Forest

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 237 ◽  
Author(s):  
Bram Hadiwijaya ◽  
Steeve Pepin ◽  
Pierre-Erik Isabelle ◽  
Daniel F. Nadeau
Keyword(s):  
Boreal Forest ◽  
Sap Flow ◽  
Boreal Forests ◽  
Cold Climate ◽  
Thermal Dissipation ◽  
Evaporative Demand ◽  
Sap Flux Density ◽  
Flow Measurements ◽  
Growing Seasons ◽  
The Impact

Humid boreal forests are unique environments characterized by a cold climate, abundant precipitation, and high evapotranspiration. Transpiration ( E T ), as a component of evapotranspiration (E), behaves differently under wet and dry canopy conditions, yet very few studies have focused on the dynamics of transpiration to evapotranspiration ratio ( E T / E ) under transient canopy wetness states. This study presents field measurements of E T / E at the Montmorency Forest, Québec, Canada: a balsam fir boreal forest that receives ∼ 1600 mm of precipitation annually (continental subarctic climate; Köppen classification subtype Dfc). Half-hourly observations of E and E T were obtained over two growing seasons using eddy-covariance and sap flow (Granier’s constant thermal dissipation) methods, respectively, under wet and dry canopy conditions. A series of calibration experiments were performed for sap flow, resulting in species-specific calibration coefficients that increased estimates of sap flux density by 34 % ± 8 % , compared to Granier’s original coefficients. The uncertainties associated with the scaling of sap flow measurements to stand E T , especially circumferential and spatial variations, were also quantified. From 30 wetting–drying events recorded during the measurement period in summer 2018, variations in E T / E were analyzed under different stages of canopy wetness. A combination of low evaporative demand and the presence of water on the canopy from the rainfall led to small E T / E . During two growing seasons, the average E T / E ranged from 35 % ± 2 % to 47 % ± 3 % . The change in total precipitation was not the main driver of seasonal E T / E variation, therefore it is important to analyze the impact of rainfall at half-hourly intervals.

scholarly journals Forests synchronize their growth in contrasting Eurasian regions in response to climate warming

2016 ◽  
Vol 113 (3) ◽  
pp. 662-667 ◽  
Author(s):  
Tatiana A. Shestakova ◽  
Emilia Gutiérrez ◽  
Alexander V. Kirdyanov ◽  
Jesús Julio Camarero ◽  
Mar Génova ◽  
...  
Keyword(s):  
Climate Warming ◽  
Boreal Forests ◽  
Ring Width ◽  
Climate Extremes ◽  
Climate Change Impacts ◽  
Terrestrial Ecosystems ◽  
Growth Patterns ◽  
Mediterranean Forests ◽  
Early 21St Century ◽  
The Impact

Forests play a key role in the carbon balance of terrestrial ecosystems. One of the main uncertainties in global change predictions lies in how the spatiotemporal dynamics of forest productivity will be affected by climate warming. Here we show an increasing influence of climate on the spatial variability of tree growth during the last 120 y, ultimately leading to unprecedented temporal coherence in ring-width records over wide geographical scales (spatial synchrony). Synchrony in growth patterns across cold-constrained (central Siberia) and drought-constrained (Spain) Eurasian conifer forests have peaked in the early 21st century at subcontinental scales (∼1,000 km). Such enhanced synchrony is similar to that observed in trees co-occurring within a stand. In boreal forests, the combined effects of recent warming and increasing intensity of climate extremes are enhancing synchrony through an earlier start of wood formation and a stronger impact of year-to-year fluctuations of growing-season temperatures on growth. In Mediterranean forests, the impact of warming on synchrony is related mainly to an advanced onset of growth and the strengthening of drought-induced growth limitations. Spatial patterns of enhanced synchrony represent early warning signals of climate change impacts on forest ecosystems at subcontinental scales.

scholarly journals Methane emissions from boreal and tropical forest ecosystems derived from in-situ measurements

2007 ◽  
Vol 7 (5) ◽  
pp. 14011-14039 ◽  
Author(s):  
V. Sinha ◽  
J. Williams ◽  
P. J. Crutzen ◽  
J. Lelieveld
Keyword(s):  
Boreal Forest ◽  
Tropical Forest ◽  
Tropical Forests ◽  
Forest Ecosystem ◽  
Boreal Forests ◽  
Forest Ecosystems ◽  
Global Budget ◽  
Night Time ◽  
Mixing Ratios ◽  
The Impact

Abstract. Methane is a climatologically important greenhouse gas, which plays a key role in regulating water vapour in the stratosphere and hydroxyl radicals in the troposphere. Recent findings that vegetation emits methane have stimulated efforts to ascertain the impact of this source on the global budget. In this work, we present the results of high frequency (ca. 1 min−1) methane measurements conducted in the boreal forests of Finland and the tropical forests of Suriname, in April–May, 2005 and October 2005 respectively. The measurements were performed using a gas chromatograph – flame ionization detector (GC-FID). The average of the median mixing ratios during a typical diel cycle were 1.83 μmol mol−1 and 1.74 μmol mol−1 for the boreal forest ecosystem and tropical forest ecosystem respectively, with remarkable similarity in the time series of both the boreal and tropical diel profiles. Night time methane emission flux of the boreal forest ecosystem, calculated from the increase of methane during the night and measured nocturnal boundary layer heights yields a flux of (3.62±0.87)×1011 molecules cm−2 s−1(or 45.5±11 Tg CH4 yr−1 for global boreal forest area). This is a source contribution of circa 8% of the global methane budget. These results highlight the importance of the boreal and tropical forest ecosystems for the global budget of methane. The results are also discussed in the context of recent work reporting high methane mixing ratios over tropical forests using space borne near infra-red spectroscopy measurements.

scholarly journals Evolution of Industrial R&D Financing in the USA: Dynamic and Structural Features

2021 ◽  
pp. 181-193
Author(s):  
Valerij Minat
Keyword(s):  
United States ◽  
Industrial Production ◽  
Structural Changes ◽  
Manufacturing Sector ◽  
The United States ◽  
Structural Features ◽  
Subject Area ◽  
Public And Private ◽  
The Usa ◽  
The Impact

The subject area of this study includes the features of the dynamics and structure of the financing of industrial R&D that have developed in the United States over the time period 1929–2019, determined by the institutional features and structural changes in the country’s industrial production. The evolution of industrial R&D financing as a socio-historical process reflects the economic transformations caused by the increased mobilization of financial resources for scientific, technical and innovative development. The purpose of the study is to identify and justify current trends in the evolution of industrial R&D financing in the United States, due to structural changes in industrial production over a long period of time. The results of the studies revealed structural relations of sources of direct funding of industrial R&D in the United States (by main areas) in the “customer– contractor” system, implemented by the public and private research programs. The empirical data obtained generally confirm the theoretical position on the impact of institutional and structural changes observed within the American manufacturing sector over the study period on the evolution of specific R&D financing in terms of increasing their concentration. It also shows the disparity in the territorial allocation of federal funding for industrial R&D in the United States.

scholarly journals The Impact of Boreal Forest Fire on Climate Warming

Science ◽  
2006 ◽  
Vol 314 (5802) ◽  
pp. 1130-1132 ◽  
Author(s):  
J. T. Randerson ◽  
H. Liu ◽  
M. G. Flanner ◽  
S. D. Chambers ◽  
Y. Jin ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Forest Fire ◽  
Climate Warming ◽  
The Impact

Snow removal reduces annual cellulose decomposition in a riparian boreal forest

2013 ◽  
Vol 93 (4) ◽  
pp. 427-433 ◽  
Author(s):  
Juergen Kreyling ◽  
Mahsa Haei ◽  
Hjalmar Laudon
Keyword(s):  
Boreal Forest ◽  
Snow Cover ◽  
Boreal Forests ◽  
Soil Depth ◽  
Decomposition Rates ◽  
Soil Frost ◽  
Snow Removal ◽  
Cellulose Decomposition ◽  
Significant Difference ◽  
The Impact

Kreyling, J., Haei, M. and Laudon, H. 2013. Snow removal reduces annual cellulose decomposition in a riparian boreal forest. Can. J. Soil Sci. 93: 427–433. Decomposition is a key process in carbon and nutrient cycling. However, little is known about its response to altered winter soil temperature regimes in boreal forests. Here, the impact of soil frost on cellulose decomposition over 1 yr and soil biotic activity (bait-lamina sticks) over winter, in spring, and in summer was investigated using a long-term (9-yr) snow-cover manipulation experiment in a boreal Picea abies forest. The experiment consisted of the treatments: snow removal, increased insulation, and ambient control. The snow removal treatment caused longer and deeper soil frost (minimum temperature −8.6°C versus −1.4°C) at 10 cm soil depth in comparison with control, while the increased insulation treatment resulted in nearly no soil frost during winter. Annual cellulose decomposition rates were reduced by 46% in the snow removal manipulation in comparison with control conditions. Increased insulation had no significant effect on decomposition. The decomposition was mainly driven by microorganisms, as no significant difference was observed for containers enclosed with a 44-µm and a 1-mm mesh. Soil biotic activity was slightly increased by both the snow removal and the increased insulation treatment in comparison with control conditions over winter. However, this effect disappeared over spring and summer. We conclude that soil frost can have strong effects on decomposition in boreal ecosystems. Further studies should investigate to which degree the observed reduction in decomposition due to reduced snow cover in winter slows or even offsets the expected increase in decomposition rates with global warming.

Effects of natural resource development on the terrestrial biodiversity of Canadian boreal forests

2014 ◽  
Vol 22 (4) ◽  
pp. 457-490 ◽  
Author(s):  
L.A. Venier ◽  
I.D. Thompson ◽  
R. Fleming ◽  
J. Malcolm ◽  
I. Aubin ◽  
...  
Keyword(s):  
Forest Management ◽  
Boreal Forest ◽  
Natural Resource ◽  
Boreal Forests ◽  
Large Scale ◽  
Resource Development ◽  
Natural Resource Development ◽  
Terrestrial Biodiversity ◽  
The Impact

Much of Canada’s terrestrial biodiversity is supported by boreal forests. Natural resource development in boreal forests poses risks to this biodiversity. This paper reviews the scientific literature to assess the effects of natural resource development on terrestrial biodiversity in Canadian boreal forests. We address four questions: (1) To what extent have Canadian boreal forests changed due to natural resource development? (2) How has biodiversity responded to these changes? (3) Will the biodiversity of second-growth forests converge with that of primary boreal forests? (4) Are we losing species from boreal forests? We focus on trees, understory plants, insects, fungi, selected mammals, and songbirds because these groups have been most studied. We review more than 600 studies and found that changes in community composition are prevalent in response to large-scale conversion of forest types, changes in stand structures and age distributions, and altered landscape structure resulting from forest management and habitat loss associated with other developments such as oil and gas, hydroelectric, and mining. The southern boreal forest has been more highly impacted than the north due to more extensive forest management and the cumulative effects of multiple forms of development. There is abundant evidence that most species are not in danger of being extirpated from the boreal forest due to these anthropogenic changes. A few species, including woodland caribou (Rangifer tarandus) and grizzly bear (Ursus arctos), have, however, undergone long-term range contractions. Significant gaps in our ability to assess the effects of natural resource development on biodiversity in the boreal zone are the lack of long-term spatial and population data to monitor the impact of forest changes on ecosystems and species.

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