Moving towards carbon neutrality: CO2 exchange of a black spruce forest ecosystem during the first 10 years of recovery after harvest

2012 ◽  
Vol 42 (11) ◽  
pp. 1908-1918 ◽  
Author(s):  
Carole Coursolle ◽  
Marc-André Giasson ◽  
Hank A. Margolis ◽  
Pierre Y. Bernier
Keyword(s):  
Boreal Forests ◽  
Black Spruce ◽  
Ecosystem Respiration ◽  
Co2 Exchange ◽  
Relative Role ◽  
Ecosystem Productivity ◽  
Eastern Canada ◽  
Post Harvest ◽  
C Dynamics ◽  
Rate Of Increase

Disturbances control the landscape-level C dynamics of boreal forests, but post-disturbance C dynamics are usually poorly quantified. In the current study, we use 10 years of CO2 flux measurements at a boreal black spruce ( Picea mariana (Mill.) B.S.P.) cutover in eastern Canada to estimate time to C neutrality, quantify the relative role of respiration versus photosynthesis during recovery, and determine the agreement between cumulated CO2 fluxes and plot-level changes in C content. The site was a net source of 139 g C·m–2·year–1 2 years post-harvest, dropped further to a source of 173 g C·m–2·year–1 4 years post-harvest, following a scarification treatment, and was nearly C neutral 10 years post-harvest. Gross ecosystem productivity (GEP) increased by 50 g C·m–2·year–1 post-scarification, while ecosystem respiration (ER) increased by only 23 g C·m–2·year–1. The resulting net rate of increase of 27 g C·m–2·year–1 in net ecosystem productivity was driven by changes in increasing leaf area. In fact, vegetation regrowth had a much greater impact on annual fluxes than did interannual variability in climate. Biometric-based measurements of total C losses after harvest were in relatively good agreement with eddy-covariance-based estimates 8 years after the harvest.

scholarly journals Influence of spring and autumn phenological transitions on forest ecosystem productivity

2010 ◽  
Vol 365 (1555) ◽  
pp. 3227-3246 ◽  
Author(s):  
Andrew D. Richardson ◽  
T. Andy Black ◽  
Philippe Ciais ◽  
Nicolas Delbart ◽  
Mark A. Friedl ◽  
...  
Keyword(s):  
Climate Change ◽  
Eddy Covariance ◽  
Boreal Forests ◽  
Ecosystem Respiration ◽  
Ecosystem Productivity ◽  
Important Conclusion ◽  
Gross Ecosystem Photosynthesis ◽  
Eddy Covariance Measurements ◽  
Phenological Shifts ◽  
Carry Over

We use eddy covariance measurements of net ecosystem productivity (NEP) from 21 FLUXNET sites (153 site-years of data) to investigate relationships between phenology and productivity (in terms of both NEP and gross ecosystem photosynthesis, GEP) in temperate and boreal forests. Results are used to evaluate the plausibility of four different conceptual models. Phenological indicators were derived from the eddy covariance time series, and from remote sensing and models. We examine spatial patterns (across sites) and temporal patterns (across years); an important conclusion is that it is likely that neither of these accurately represents how productivity will respond to future phenological shifts resulting from ongoing climate change. In spring and autumn, increased GEP resulting from an ‘extra’ day tends to be offset by concurrent, but smaller, increases in ecosystem respiration, and thus the effect on NEP is still positive. Spring productivity anomalies appear to have carry-over effects that translate to productivity anomalies in the following autumn, but it is not clear that these result directly from phenological anomalies. Finally, the productivity of evergreen needleleaf forests is less sensitive to phenology than is productivity of deciduous broadleaf forests. This has implications for how climate change may drive shifts in competition within mixed-species stands.

scholarly journals Complete Chloroplast Genome Sequence of a Black Spruce (Picea mariana) from Eastern Canada

2020 ◽  
Vol 9 (39) ◽  
Author(s):  
Theodora Lo ◽  
Lauren Coombe ◽  
Diana Lin ◽  
René L. Warren ◽  
Heather Kirk ◽  
...  
Keyword(s):  
Chloroplast Genome ◽  
Genome Sequence ◽  
Picea Mariana ◽  
Boreal Forests ◽  
Genetic Basis ◽  
Black Spruce ◽  
Eastern Canada ◽  
Complete Chloroplast Genome ◽  
Content Type ◽  
Chloroplast Genome Sequence

ABSTRACT Here, we present the chloroplast genome sequence of black spruce (Picea mariana), a conifer widely distributed throughout North American boreal forests. This complete and annotated chloroplast sequence is 123,961 bp long and will contribute to future studies on the genetic basis of evolutionary change in spruce and adaptation in conifers.

Assessing the potential of the differenced Normalized Burn Ratio (dNBR) for estimating burn severity in eastern Canadian boreal forests

2017 ◽  
Vol 26 (1) ◽  
pp. 32 ◽  
Author(s):  
Jonathan Boucher ◽  
André Beaudoin ◽  
Christian Hébert ◽  
Luc Guindon ◽  
Éric Bauce
Keyword(s):  
Boreal Forests ◽  
Black Spruce ◽  
Additive Model ◽  
Time Frame ◽  
Burn Severity ◽  
Eastern Canada ◽  
Generalised Additive Model ◽  
Boreal Region ◽  
Differenced Normalized Burn Ratio ◽  
Normalized Burn Ratio

There is considerable variation in the degree of burn severity in boreal fires. One approach that has been used to capture this variation from field and remote sensing perspectives for western Canadian boreal forests is the Composite Burn Index (CBI) and differenced Normalized Burn Ratio (dNBR). Of interest was how well these methods may perform for fires in eastern Canada. This study investigated the CBI-dNBR relationship for selected fires in the eastern boreal forests of Canada, with a view towards contributing to the generalisation of a Canada-wide model. Results for the sampled region showed no difference in the CBI-dNBR relationship between black spruce- and jack pine-dominated stands, whereas this relationship was best described by a Generalised Additive Model (GAM). The dNBR-derived maps would also be useful in support of research and post-fire management in burns outside the studied territory and time frame covered by the existing burn severity mapping system already used in this region. The Saturated growth model proposed for the western boreal region also performed well for our eastern boreal region, thus further supporting the development of a national model.

scholarly journals Forest Floor Carbon Exchange of a Boreal Black Spruce Forest in Eastern Canada

2009 ◽  
Vol 6 (3) ◽  
pp. 5507-5548 ◽  
Author(s):  
O. Bergeron ◽  
H. A. Margolis ◽  
C. Coursolle
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Forest Floor ◽  
Black Spruce ◽  
Ecosystem Respiration ◽  
Light Availability ◽  
Ground Cover ◽  
Spruce Forest ◽  
Eastern Canada ◽  
Shallow Soil

Abstract. This study reports continuous automated measurements of forest floor carbon (C) exchange over feathermoss, lichen, and sphagnum micro-sites in a black spruce forest in eastern North America during snow-free periods over three years. The response of soil respiration (Rs-auto) and forest floor photosynthesis (Pff) to environmental factors was determined. The seasonal contributions of scaled up Rs-auto adjusted for spatial representativeness (Rs-adj) and Pff (Pff-eco) relative to that of total ecosystem respiration (Re) and photosynthesis (Peco), respectively, were also quantified. Shallow soil temperature explained 67–86% of the variation in Rs-auto for all ground cover types, while deeper soil temperatures were related to Rs-auto only for the feathermoss micro-sites. Base respiration was consistently lower under feathermoss, intermediate under sphagnum, and higher under lichen during all three years. The Rs-adj/Re ratio increased from spring through autumn and ranged from 0.85 to 0.87 annually for the snow-free period. The Rs-adj/Re ratio was negatively correlated with the difference between air and shallow soil temperature and this correlation was more pronounced in autumn than summer and spring. Maximum photosynthetic capacity of the forest floor (Pffmax) saturated at low irradiance levels (~200 μmol m−2 s−1) and decreased with increasing air temperature and vapor pressure deficit for all three ground cover types, suggesting that Pff was more limited by desiccation than by light availability. Pffmax was lowest for sphagnum, intermediate for feathermoss, and highest for lichen for two of the three years. Pff normalized for light peaked at air temperatures of 5–8°C, suggesting that this is the optimal temperature range for Pff. The Pff-eco/Peco ratio varied seasonally from 13 to 24% and reached a minimum in mid-summer when both air temperature and Peco were at their maximum. On an annual basis, Pff-eco accounted for 17–18% of Peco depending on the year and the snow-free season totals of Pff-adj were 23–24% that of Rs-adj.

scholarly journals Previous growing season climate controls the occurrence of black spruce growth anomalies in boreal forests of Eastern Canada

2016 ◽  
Vol 46 (5) ◽  
pp. 696-705 ◽  
Author(s):  
Clémentine Ols ◽  
Annika Hofgaard ◽  
Yves Bergeron ◽  
Igor Drobyshev
Keyword(s):  
Climate Change ◽  
Tree Growth ◽  
Boreal Forests ◽  
Black Spruce ◽  
Spatial Scales ◽  
Growing Season ◽  
Eastern Canada ◽  
Late 20Th Century ◽  
Growth Anomalies

To better understand climatic origins of annual tree-growth anomalies in boreal forests, we analysed 895 black spruce (Picea mariana (Mill.) B.S.P.) tree-growth series from 46 xeric sites situated along three latitudinal transects in Eastern Canada. We identified interannual (based on comparison with previous year growth) and multidecadal (based on the entire tree-ring width distribution) growth anomalies between 1901 and 2001 at site and transect levels. Growth anomalies occurred mainly at site level and seldom at larger spatial scales. Both positive interannual and multidecadal growth anomalies were strongly associated with below-average temperatures and above-average precipitation during the previous growing season (Junet–1 – Augustt–1). The climatic signature of negative interannual and multidecadal growth anomalies was more complex and mainly associated with current-year climatic anomalies. Between the early and late 20th century, only negative multidecadal anomalies became more frequent. Our results highlight the role of previous growing season climate in controlling tree growth processes and suggest a positive association between climate warming and increases in the frequency of negative multidecadal growth anomalies. Projected climate change may further favour the occurrence of tree-growth anomalies and enhance the role of site conditions as modifiers of tree response to regional climate change.

scholarly journals Growth dynamics of successive post-fire cohorts of black spruce: Is site potential reduced?

2014 ◽  
Vol 90 (01) ◽  
pp. 96-104 ◽  
Author(s):  
D. Côté ◽  
C. Lupi ◽  
R. Gagnon ◽  
D. Lord ◽  
H. Morin
Keyword(s):  
Boreal Forests ◽  
Forest Cover ◽  
Black Spruce ◽  
Growth Dynamics ◽  
Single Species ◽  
Nonparametric Test ◽  
Growth Potential ◽  
Eastern Canada ◽  
Mean Values ◽  
Cambial Age

Black spruce is one of the main commercial species in boreal forests of North America. It usually forms large and single-species natural stands in eastern Canada, yet in recent years, parts of this area have undergone forest cover regression and the conversion of closed-crown forests to open lichen woodlands, partly due to successive disturbances and regeneration accidents. We studied two successive post-fire cohorts growing at the same site, for which a clear forest cover regression trajectory has already been demonstrated, to assess possible changes in the site potential. The Wilcoxon nonparametric test found significant differences in mean diameter and height growth between cohorts, compared by cambial age, generally with higher mean values for the most recent cohort. There were no indications of growth reduction between the previous and the current cohorts. This paper sets the ball rolling for a discussion on the pertinence of reforestation in this type of recently established open formation, where growth potential (as expressed by diameter and height) seems, at least, maintained.

scholarly journals Responses of Forest Carbon Cycle to Drought and Elevated CO2

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 212
Author(s):  
Jun-Lan Xiao ◽  
Feng Zeng ◽  
Qiu-Lan He ◽  
Yu-Xia Yao ◽  
Xiao Han ◽  
...  
Keyword(s):  
Water Stress ◽  
Elevated Co2 ◽  
Carbon Sink ◽  
Ecosystem Respiration ◽  
Co2 Exchange ◽  
Positive Influence ◽  
Research Field ◽  
Co2 Fertilization ◽  
Global Trends ◽  
Elevated Atmospheric Co2

Forests play a pivotal role in mitigating global warming as an important carbon sink. Recent global greening trends reflect a positive influence of elevated atmospheric CO2 on terrestrial carbon uptake. However, increasingly frequent and intense drought events endanger the carbon sequestration function of forests. This review integrates previous studies across scales to identify potential global trends in forest responses to drought and elevated CO2 as well as to identify data needs in this important research field. The inconsistent responses of ecosystem respiration to drought contributes to the change of forest net CO2 exchange, which depends on the balance of opposite effects of warming and water stress on respiration. Whether CO2 fertilization can offset the effects of drought remains controversial, however, we found a potential overestimation of global CO2 fertilization effects because of increasing water stress and other limitations such as light and nutrients (N, P) as well as the possibility of photosynthetic acclimation.

scholarly journals The Delphi method as an alternative to standard committee meetings to identify ecological issues for forest ecosystem-based management: A case study

2016 ◽  
Vol 92 (04) ◽  
pp. 453-464 ◽  
Author(s):  
K. Waldron ◽  
J.-M Lussier ◽  
N. Thiffault ◽  
F. Bujold ◽  
J.-C. Ruel ◽  
...  
Keyword(s):  
Forest Ecosystem ◽  
Delphi Method ◽  
Boreal Forests ◽  
Expert Consultation ◽  
Committee Meeting ◽  
Eastern Canada ◽  
Face To Face ◽  
Time Investment ◽  
Second Growth ◽  
The Face

The face-to-face committee meeting is one of the most common expert consultation methods used in forest management. However, it is also laden with disadvantages, such as potential inequity in its consideration of participant opinion and the time involvement required. This led us to evaluate another expert consultation method, the Delphi method, namely by implementing it to identify ecological issues associated with second-growth boreal forests in eastern Canada. We compared this method to the committee meeting method with regard to the time investment required and the efficiency of the consultations. In all, 21 experts participated in three rounds of our implementation of the Delphi method. Subsequently, we administered an appreciation survey comparing the participants’ attitudes vis-à-vis the two methods. These comparisons showed that Delphi was less time-consuming compared to a committee meeting consultation of comparable scope. Participants also considered the Delphi method to be fair and impartial, as all opinions were considered, which is frequently not the case in committee meetings. That said, participants believed that committee meetings allowed for a greater understanding of others’ opinions. Overall, the application of the Delphi method was shown to be a promising way of determining forest ecosystem management issues.

Sign in / Sign up

Export Citation Format

Share Document