Mathilde Pau, Sylvie Gauthier, Yan Boulanger, Hakim Ouzennou, Martin-Philippe Girardin, Yves Bergeron. Response of forest productivity to changes in growth and
fire regime due to climate change. 2023. Can. J. For. Res. Online first
DOI : 10.1139/cjfr-2022-0207
Climate change is having complex impacts on the boreal forest, modulating both tree growth limiting factors and fire regime. However, these aspects are usually projected independently when estimating climate change effect on the boreal forest. Using a combination of three different methods, our goal is to assess the combined impact of changes in growth and fire regime due to climate change on the timber supply at the transitions from closed to open boreal coniferous forests in Québec, Canada. To identify the areas that are likely to be the most sensitive to climate change, we projected climate-induced impacts on growth and fire activity at three different time periods: 2011–2040 RCP 8.5 for low growth change and minimum fire activity, 2071–2100 RCP 4.5 for moderate growth change and medium fire activity, and 2071–2100 RCP 8.5 for high growth change and maximum fire activity. Our study shows the importance of incorporating fire in strategic forest management planning especially in a context of climate change. Under the most extreme scenarios, the negative impact of fire activity on productive area and total volume mostly offsets the positive effects of climate change via improved tree growth.
Dorian Gaboriau, Emeline Chaste, Martin-Philippe Girardin, Hugo Asselin, Adam Ali, Yves Bergeron, Christelle Hely-Alleaume. Interactions within the climate-vegetation-fire nexus may transform 21st century boreal forests in northwestern Canada. 2023. iScience 26:106807
DOI : 10.1016/j.isci.2023.106807
Dry and warm conditions have exacerbated the occurrence of large and severe wildfires over the past decade in Canada’s Northwest Territories (NT). While temperatures are expected to increase during the 21st century, we lack understanding of how the climate-vegetation-fire nexus might respond. We used a dynamic global vegetation model to project annual burn rates, as well as tree species composition and biomass in the NT during the 21st century using the IPCC’s climate scenarios. Burn rates will decrease in most of the NT by the mid-21st century, concomitant with biomass loss of fire-prone evergreen needleleaf tree species, and biomass increase of broadleaf tree species. The southeastern NT is projected to experience enhanced fire activity by the late 21st century according to scenario RCP4.5, supported by a higher production of flammable evergreen needleleaf biomass. The results underlie the potential for major impacts of climate change on the NT’s terrestrial ecosystems.
Clémentine Ols, Stefan Kless, Martin-Philippe Girardin, Margaret E.K. Evans, Justin DeRose, Valérie Trouet. Detrending climate data prior to climate–growth analyses in dendroecology: A common best practice? 2023. Dendrochronologia 79:126094
DOI : 10.1016/j.dendro.2023.126094
Tree growth varies closely with high–frequency climate variability. Since the 1930s detrending climate data prior to comparing them with tree growth data has been shown to better capture tree growth sensitivity to climate. However, in a context of increasingly pronounced trends in climate, this practice remains surprisingly rare in dendroecology. In a review of Dendrochronologia over the 2018–2021 period, we found that less than 20 % of dendroecological studies detrended climate data prior to climate-growth analyses. With an illustrative study, we want to remind the dendroecology community that such a procedure is still, if not more than ever, rational and relevant. We investigated the effects of detrending climate data on climate–growth relationships across North America over the 1951–2000 period. We used a network of 2536 tree individual ring-width series from the Canadian and Western US forest inventories. We compared correlations between tree growth and seasonal climate data (Tmin, Tmax, Prec) both raw and detrended. Detrending approaches included a linear regression, 30-yr and 100-yr cubic smoothing splines. Our results indicate that on average the detrending of climate data increased climate–growth correlations. In addition, we observed that strong trends in climate data translated to higher variability in inferred correlations based on raw vs. detrended climate data. We provide further evidence that our results hold true for the entire spectrum of dendroecological studies using either mean site chronologies and correlations coefficients, or individual tree time series within a mixed-effects model framework where regression coefficients are used more commonly. We show that even without a change in correlation, regression coefficients can change a lot and we tend to underestimate the true climate impact on growth in case of climate variables containing trends. This study demonstrates that treating climate and tree-ring time series “like-for-like” is a necessary procedure to reduce false negatives and positives in dendroecological studies. Concluding, we recommend using the same detrending for climate and tree growth data when tree-ring time series are detrended with splines or similar frequency-based filters.
Raphaël Chavardes, Victor Danneyrolles, Jeanne Portier, Martin-Philippe Girardin, Dorian Gaboriau, Sylvie Gauthier, Igor Drobyshev, Tuomo Wallenius, Dominic Cyr, Yves Bergeron. Converging and diverging burn rates in North American boreal forests from the Little Ice Age to the present 2022. International Journal of Wildland Fire 31(12):1184-1193
DOI : 10.1071/WF22090
Warning: This article contains terms, descriptions, and opinions used for historical context that may be culturally sensitive for some readers.Background: Understanding drivers of boreal forest dynamics supports adaptation strategies in the context of climate change.Aims: We aimed to understand how burn rates varied since the early 1700s in North American boreal forests.Methods: We used 16 fire-history study sites distributed across such forests and investigated variation in burn rates for the historical period spanning 1700-1990. These were benchmarked against recent burn rates estimated for the modern period spanning 1980-2020 using various data sources.Key results: Burn rates during the historical period for most sites showed a declining trend, particularly during the early to mid 1900s. Compared to the historical period, the modern period showed less variable and lower burn rates across sites. Mean burn rates during the modern period presented divergent trends among eastern versus northwestern sites, with increasing trends in mean burn rates in most northwestern North American sites.Conclusions: The synchronicity of trends suggests that large spatial patterns of atmospheric conditions drove burn rates in addition to regional changes in land use like fire exclusion and suppression.Implications: Low burn rates in eastern Canadian boreal forests may continue unless climate change overrides the capacity to suppress fire.
Ellis Q. Margolis, Christopher H. Guiterman, Raphaël Chavardes, Jonathan D. Coop, Kelsey Copes-Gerbitz, Denyse A. Dawe, Donald A. Falk, James D. Johnston, Evan Larson, Hang Li, Joseph M. Marschall, Cameron E. Naficy, Adam T. Naito, Marc-André Parisien, Sean A. Parks, Jeanne Portier, Helen M. Poulos, Kevin M. Robertson, James H. Speer, Michael Stambaugh, Thomas W. Swetnam, Alan J. Tepley, Ichchha Thapa, Craig D. Allen, Yves Bergeron, Lori D. Daniels, Peter Z. Fulé, David Gervais, Martin-Philippe Girardin, Grant L. Harley, Jill E. Harvey, Kira M. Hoffman, Jean M. Huffman, Matthew D. Hurteau, Lane B. Johnson, Charles W. Lafon, Manuel K. Lopez, R. Stockton Maxwell, Jed Meunier, Malcolm North, Monica T. Rother, Micah R. Schmidt, Rosemary L. Sherriff, Lauren A. Stachowiak, Alan Taylor, Erana J. Taylor, Valérie Trouet, Miguel L. Villarreal, Larissa L. Yocom, Karen B. Arabas, Alexis H. Arizpe, Dominique Arseneault, Alicia Azpeleta Tarancón, Christopher Baisan, Erica Bigio, Franco Biondi, Gabriel D. Cahalan, Anthony Caprio, Julián Cerano-Paredes, Brandon M. Collins, Daniel C. Dey, Igor Drobyshev, Calvin Farris, M. Adele Fenwick, William Flatley, M. Lisa Floyd. The North American tree-ring fire-scar network. 2022. Ecosphere 13(7):e4159
DOI : 10.1002/ecs2.4159
Abstract Fire regimes in North American forests are diverse and modern fire records are often too short to capture important patterns, trends, feedbacks, and drivers of variability. Tree-ring fire scars provide valuable perspectives on fire regimes, including centuries-long records of fire year, season, frequency, severity, and size. Here, we introduce the newly compiled North American tree-ring fire-scar network (NAFSN), which contains 2562 sites, >37,000 fire-scarred trees, and covers large parts of North America. We investigate the NAFSN in terms of geography, sample depth, vegetation, topography, climate, and human land use. Fire scars are found in most ecoregions, from boreal forests in northern Alaska and Canada to subtropical forests in southern Florida and Mexico. The network includes 91 tree species, but is dominated by gymnosperms in the genus Pinus. Fire scars are found from sea level to >4000-m elevation and across a range of topographic settings that vary by ecoregion. Multiple regions are densely sampled (e.g., >1000 fire-scarred trees), enabling new spatial analyses such as reconstructions of area burned. To demonstrate the potential of the network, we compared the climate space of the NAFSN to those of modern fires and forests; the NAFSN spans a climate space largely representative of the forested areas in North America, with notable gaps in warmer tropical climates. Modern fires are burning in similar climate spaces as historical fires, but disproportionately in warmer regions compared to the historical record, possibly related to under-sampling of warm subtropical forests or supporting observations of changing fire regimes. The historical influence of Indigenous and non-Indigenous human land use on fire regimes varies in space and time. A 20th century fire deficit associated with human activities is evident in many regions, yet fire regimes characterized by frequent surface fires are still active in some areas (e.g., Mexico and the southeastern United States). These analyses provide a foundation and framework for future studies using the hundreds of thousands of annually- to sub-annually-resolved tree-ring records of fire spanning centuries, which will further advance our understanding of the interactions among fire, climate, topography, vegetation, and humans across North America.
Dorian Gaboriau, Adam Ali, Christelle Hely-Alleaume, Hugo Asselin, Martin-Philippe Girardin. Drivers of extreme wildfire years in the 1965–2019 fire regime of the Tłı̨chǫ First Nation territory, Canada 2022. Ecoscience 29(3):249-265
DOI : 10.1080/11956860.2022.2070342
Exceptionally large areas burned in 2014 in central Northwest Territories (Canada), leading members of the Tłı̨chǫ First Nation to characterize this year as ‘extreme’. Top-down climatic and bottom-up environmental drivers of fire behavior and areas burned in the boreal forest are relatively well understood, but not the drivers of extreme wildfire years (EWY). We investigated the temporal and spatial distributions of fire regime components (fire occurrence, size, cause, fire season length) on the Tłı̨chǫ territory from 1965 to 2019. We used BioSIM and data from weather stations to interpolate mean weather conditions, fuel moisture content and fire-weather indices for each fire season, and we described the environmental characteristics of burned areas. We identified and characterized EWY, i.e., years exceeding the 80th percentile of annual area burned for the study period. Temperature and fuel moisture were the main drivers of areas burned. Nine EWY occurred from 1965 to 2019, including 2014. Compared to non-EWY, EWY had significantly higher mean temperature (>14.7°C) and exceeded threshold values of Drought Code (>514), Initial Spread Index (>7), and Fire Weather Index (>19). Our results will help limit the effects of EWY on human safety, health and Indigenous livelihoods and lifestyles.
Alexandre Florent Nolin, Xiao Jing Guo, Yves Bergeron, Martin-Philippe Girardin, Jacques Tardif, France Conciatori. A 247-year tree-ring reconstruction of spring temperature
and relation to spring flooding in eastern boreal Canada. 2022. Int. J. Climatol. 42(12):6479-6498
DOI : 10.1002/joc.7608
Few records of spring paleoclimate are available for boreal Canada, as biological proxies recording the beginning of the warm season are uncommon. Given the spring warming observed during the last decades, and its impact on snowmelt and hydrological processes, searching for spring climate proxies is receiving increasing attention. Tree-ring anatomical features and intra-annual widths were used to reconstruct the regional March to May mean air temperature from 1770 to 2016 in eastern boreal Canada. Nested principal component regressions calibrated on 116 years of gridded temperature data were developed from one Fraxinus nigra and 10 Pinus banksiana sites. The reconstruction indicated three distinct phases in spring temperature variability since 1770. Ample phases of multi-decadal warm and cold springs persisted until the end of the Little Ice Age (1850–1870 CE) and were gradually replaced since the 1940s by decadal to interannual variability associated with an increase in the frequency and magnitude of warm springs. Significant correlations with other paleotemperature records, gridded snow cover extent and runoff support that historical high flooding were associated with late, cold springs with heavy snow cover. Most of the high magnitude spring floods reconstructed for the nearby Harricana River also coincided with the lowest reconstructed spring temperature per decade. However, the last 40 years of observed and reconstructed mean spring temperature showed a reduction in the number of extreme cold springs contrasting with the last few decades of extreme flooding in the eastern Canadian boreal region. This result indicates that warmer late spring mean temperatures on average may contribute, among other factors, to advance the spring break-up and to likely shift the contribution of snow to rain in spring flooding processes.
Emmanuel Amoah Boakye, Daniel Houle, Yves Bergeron, Igor Drobyshev, Martin-Philippe Girardin. Insect defoliation modulates influence of climate on the growth
of tree species in the boreal mixed forests of eastern Canada 2022. Ecology and Evolution 12(3):e8656
DOI : 10.1002/ece3.8656
Increasing air temperatures and changing precipitation patterns due to climate change can affect tree growth in boreal forests. Periodic insect outbreaks affect the growth trajectory of trees, making it difficult to quantify the climate signal in growth dynamics at scales longer than a year. We studied climate-driven growth trends and the influence of spruce budworm (Choristoneura fumiferana Clem.) outbreaks on these trends by analyzing the basal area increment (BAI) of 2058 trees of Abies balsamea (L.) Mill., Picea glauca (Moench) Voss, Thuja occidentalis L., Populus tremuloides Michx., and Betula papyrifera Marsh, which co-occurs in the boreal mixedwood forests of western Quebec. We used a generalized additive mixed model (GAMM) to analyze species-specific trends in BAI dynamics from 1967 to 1991. The model relied on tree size, cambial age, degree of spruce budworm defoliation, and seasonal climatic variables. Overall, we observed a decreasing growth rate of the spruce budworm host species, A. balsamea and P. glauca between 1967 and 1991, and an increasing growth rate for the non-host, P. tremuloides, B. papyrifera, and T. occidentalis. Our results suggest that insect outbreaks may offset growth increases resulting from a warmer climate. The observation warrants the inclusion of the spruce budworm defoliation into models predicting future forest productivity.
Sandy P. Harrison, Roberto Villegas-Diaz, Esmeralda Cruz-Silva, Daniel Gallagher, David Kesner, Paul Lincoln, Yicheng Shen, Luke Sweeney, Daniele Colombaroli, Adam Ali, Chéïma Barhoumi , Yves Bergeron, Tatiana Blyakharchuk, Přemysl Bobek, R.H.W. Bradshaw, Jennifer L. Clear, Sambor Czerwiński, Anne-Laure Daniau, John Dodson, Kevin J. Edwards, M.E. Edwards, A. Feurdean, D. Foster, K. Gajewski, M. Gałka, Michelle Garneau, T. Giesecke, G. Gil Romera, Martin-Philippe Girardin, D. Hoefer, K. Huang, J. Inoue, E. Jamrichová, N. Jasiunas, W. Jiang, G. Jiménez-Moreno, M. Karpińska-Kołaczek, P. Kołaczek, N. Kuosmanen, Mariusz Lamentowicz, Martin Lavoie, F. Li, J. Li, O. Lisitsyna, J.A. López-Sáez, R. Luelmo-Lautenschlaeger, Gabriel Magnan, E.K. Magyari, A. Maksims, K. Marcisz, E. Marinova, J. Marlon, S. Mensing, J. Miroslaw-Grabowska, W. Oswald, S. Pérez-Dı́az, R. Pérez-Obiol, S. Piilo, A. Poska, X. Qin, Cécile Remy, Pierre J.H. Richard, S. Salonen, N. Sasaki, H. Schneider, W. Shotyk, M. Stancikaite, D. Šteinberga, N. Stivrins, H. Takahara, Z. Tan, L. Trasune, C.E. Umbanhowar, M. Väliranta, J. Vassiljev, X. Xiao, Q. Xu, X. Xu, E. Zawisza, Y. Zhao, Z. Zhou, Jordan Paillard. The Reading Palaeofire Database: an expanded global resource to document changes in fire regimes from sedimentary charcoal records. 2022. Earth Syst. Sci. Data 14:1109-1124
DOI : 10.5194/essd-14-1109-2022
Sedimentary charcoal records are widely used to reconstruct regional changes in fire regimes through time in the geological past. Existing global compilations are not geographically comprehensive and do not provide consistent metadata for all sites. Furthermore, the age models provided for these records are not harmonised and many are based on older calibrations of the radiocarbon ages. These issues limit the use of existing compilations for research into past fire regimes. Here, we present an expanded database of charcoal records, accompanied by new age models based on recalibration of radiocarbon ages using IntCal20 and Bayesian age-modelling software. We document the structure and contents of the database, the construction of the age models, and the quality control measures applied. We also record the expansion of geographical coverage relative to previous charcoal compilations and the expansion of metadata that can be used to inform analyses. This first version of the Reading Palaeofire Database contains 1676 records (entities) from 1480 sites worldwide. The database (RPDv1b – Harrison et al., 2021) is available at https://doi.org/10.17864/1947.000345.
Fougère Augustin, Martin-Philippe Girardin, Aurélie Terrier, Pierre Grondin, Marie-Claude Lambert, Alain Leduc, Yves Bergeron. Projected changes in fire activity and severity feedback in the spruce–Feather moss forest of western Quebec, Canada. 2022. Trees, Forests and People 8:100229
DOI : 10.1016/j.tfp.2022.100229
As a result of extreme weather conditions associated with anthropogenic climate change, fire regimes are expected to continue to change in the boreal forest over the 21st century and beyond. Consequently, changes in ecological attributes like stand composition, tree density and forest carbon stock can be expected. In the present study, we used an adjusted version of the CanFIRE model to project long-term (1971–2100) changes in burn rates, fire severity and fire-induced shifts in vegetation composition in response to anticipated scenarios of climate change, in the black spruce-feather moss subdomain of Western Quebec. The model provides decadal-scale estimates of the immediate physical effects of fire on forest communities by computing expected fire behavior and the resulting ecological effects. Changes in species composition of the forest is also computed based on mechanisms of succession in natural forest communities and fire-mediated vegetation transitions. Projections suggest an increase in potential burn rates across the study area under future weather conditions and also an overall reduction in percent tree mortality and total fuel consumption. This reduction is caused by negative feedback from vegetation composition that shifts to less-fire prone states. Although common forest communities will remain the same in the studied subdomain until 2100 (recurrence dynamics), significant losses of productive area (LPA) are projected, particularly in forest management units rich in forest communities dominated by black spruce or jack pine, as a result of regeneration failure due to very short intervals between successive fires. While remaining similar under moderate (RCP4.5) and high-end (RCP8.5) warming scenarios in all forest management units, LPA will vary from 25 to 36% of the percent cover by 2100 compared to 1970. These results provide insights to policy makers and land managers, and they attract attention to the pressing need to adjust management practices in the context of climate change.
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Dorian Gaboriau, Raphaël Chavardes, Victor Danneyrolles, Jeanne Portier, Martin-Philippe Girardin, Sylvie Gauthier, Igor Drobyshev. Convergence et divergence des taux de brûlage dans les forêts boréales d'Amérique du Nord, du petit âge glaciaire à aujourd'hui 16e colloque annuel du CEF, Université de Montréal (2023-05-08)
Martin-Philippe Girardin La dendrochronologie à l’aire des changements climatiques Axe écologie UQAM (2023-04-19)
Emmanuel Amoah Boakye, Yves Bergeron, Martin-Philippe Girardin. Spatial heterogeneity of climate and topography modulates the growth of sugar maple (Acer saccharum Marsh.) trees in eastern Canada 15e colloque annuel du CEF, Université de Sherbrooke, Québec (2022-09-29)
Emmanuel Amoah Boakye, Igor Drobyshev, Yves Bergeron, Martin-Philippe Girardin. Contrasting growth response of jack pine and trembling aspen to climate warming in Quebec mixedwoods forests of eastern Canada 22e colloque de la Chaire AFD. Université du Québec en Abitibi-Témiscamingue, complètement virtuel (2020-12-02)
Mathilde Pau, Sylvie Gauthier, Raphaël Chavardes, Martin-Philippe Girardin, William Marchand, Yves Bergeron. Une nouvelle approche suggère que le réchauffement climatique pourrait augmenter la croissance des arbres en forêt boréale 22e colloque de la Chaire AFD. Université du Québec en Abitibi-Témiscamingue, complètement virtuel (2020-12-02)
Henrik Hartmann, William Marchand, Martin-Philippe Girardin, Yves Bergeron, Nathalie Isabel, Claire Depardieu, Sylvie Gauthier, Étienne Boucher. Effet des changements climatiques sur l’efficience d’utilisation de l’eau de l’épinette noire et du pin gris 21e colloque de la Chaire AFD. Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, Québec. (2019-11-30)
William Marchand, Martin-Philippe Girardin, Yves Bergeron. Facteurs régissant la croissance des peuplements boréaux aux différents stades de développement dans un contexte de changements climatiques récents 20e colloque de la Chaire AFD. Université du Québec en Abitibi-Témiscamingue, Lorrainville, Québec. (2018-11-30)
Johann Housset, Martin-Philippe Girardin, Christopher Carcaillet, Yves Bergeron. Effets des changements climatiques sur les populations marginales nordiques de Thuja occidentalis au Québec 17e colloque de la Chaire AFD. Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, Québec. (2015-12-02)
Martin-Philippe Girardin, Jacques Tardif, Micheal Flannigan, Yves Bergeron. Reconstructing atmospheric circulation history using tree rings: one more step toward understanding temporal changes in forest dynamics 3rd International Sustainable Forest Management Network Conference, Shaw Conference Centre, Edmonton, Alberta, Canada.
Martin-Philippe Girardin Multicentury reconstruction of the Canadian Drought Code, eastern Canada, and its relationships with atmospheric circulation 6th International Conference on Dendrochronlogy, University Laval, Québec, Canada.
Martin-Philippe Girardin Synoptic scale atmospheric circulation and fire weather conditions of the past three centuries, Boreal Canada The Canadian Association of Geographers annual meeting, London, Ontario, Canada.
Martin-Philippe Girardin Population dynamics of Tamarack (Larix laricina (Du Roi) K. Koch) growing in wetlands from the southwestern Quebec boreal forest 85th Annual Meeting of the Ecological Society of America, Snowbird, Utah, USA.
Jian-Guo Huang, Yves Bergeron, Jacques Tardif, Bernhard Denneler, Frank Berninger, Martin-Philippe Girardin. Response of four major boreal tree species to climate warming along a latitudinal gradient in western Quebec, Canada 1st American Dendro Conference, Vancouver, BC.
Martin-Philippe Girardin Caractère non-stationnaire et cyclique du climat de l’est canadien au cours des trois cent dernières années et son impact sur la forêt boréale mixte 2e Colloque conjoint CRBF / GREFi - La forêt sous tout ses aspects. Pavillon La Laurentienne, Université Laval, Québec, Québec.
Martin-Philippe Girardin Dynamique des tourbières dominées par le mélèze (Larix laricina) dans la forêt boréale du sud-ouest québécois 68ième congrès annuel de l’ACFAS. Université de Montréal, Québec, Canada.
Martin-Philippe Girardin, Jacques Tardif, Micheal Flannigan, Yves Bergeron. Synoptic scale atmospheric circulation and summer drought variability of the past three centuries, Boreal Canada 90th Annual Meeting of the Ecological Society of America, Montreal, Quebec, Canada.