Profile

Laurent Lamarque
Postdoctoral fellow
Department of Environmental Sciences
UQTR
llamarqueab@gmail.com

Supervised by:

Vincent Maire (Regular member)

Co-supervised by:

Esther Lévesque (Regular member)

Research project description

Physiological responses of arctic erect shrubs to drought conditions

IntroductionOne major characteristic of arctic vegetation change over the last two decades in response to increasing global warming is the widespread increase in shrub height, biomass and canopy cover. However, this so-called ‘shrubification’ is heterogeneous across the arctic tundra biome, and particularly sensitive to soil moisture conditions. Shrub growth has indeed been found higher at sites with greater soil moisture. ObjectivesThis project aims at testing the underlying plant physiological mechanisms that could explain shrub limited growth under low soil moisture conditions. In other words, we are interested in determining the extent to which Arctic shrubs can resist drought. To do so, in-lab wood anatomical and dendrochronological analyses are conducted to assess the variability of growth and hydraulic traits to changes in soil moisture conditions. In situ measurements of plant water potential and stomatal closure are also planned to estimate plant hydraulic safety margin across a soil moisture gradient. Study sitesThis study primarily uses a soil moisture gradient located near Umiujaq. Further analyses will be conducted across a latitudinal gradient using wood samples from Parc National de la Gaspésie, Parc National des Hautes-Gorges-de-la-Rivière-Malbaie, Boniface River and Kangiqsualujjuaq. Material and methodsOur species of interest is the American dwarf birch (Betula glandulosa Michx.). In Umiujaq, the soil moisture gradient has been divided in three different habitats varying in soil moisture content, and around ten individuals were sampled per habitat. Around ten individuals will also be sampled in each study site from the latitudinal gradient. Dendrochonological and wood anatomical observations are conducted using high-resolution images taken from main stem cross-sections. In situ water potential measurements will be carried out using a Scholander pressure bomb, while stomatal conductance measurements will be obtained using an infrared gas analyzer. Expected resultsThe traits measured and related to plant hydraulics and wood anatomy are expected to be highly variable in response to changes in soil moisture content. Birch individuals from the driest sites are expected to exhibit a reduced hydraulic safety margin, which would explain why shrub growth is limited in this type of habitats.

Research Site Coordinates

Scientific Communications

Lamarque, L., Jim, F.-F., Deschamps, L., Lévesque, E., Cusson, P.-O., Fortier, D., Giacomazzo, M., Guillemette, F., Paillassa, J., Tremblay, M., Maire, V., 2023. Hydrological Regime and Plant Functional Traits Jointly Mediate the Influence of Salix spp. on Soil Organic Carbon Stocks in a High Arctic Tundra. Ecosystems. DOI: 10.1007/s10021-023-00829-1.

Thomas, H.J.D., Bjorkman, A.D., Myers-Smith, I.H., Elmendorf, S.C., Kattge, J., Díaz, S., Vellend, M., Blok, D., Cornelissen, J.H.C., Forbes, B.C., Henry, G.H.R., Hollister, R.D., Normand, S., Prevéy, J.S., Rixen, C., Schaepman-Strub, G., Wilmking, M., Wipf, S., Cornwell, W.K., Beck, P.S.A., Georges, D., Goetz, S.J., Guay, K.C., Rüger, N., Soudzilovskaia, N.A., Spasojevic, M.J., Alatalo, J.M., Alexander, H.D., Anadon-Rosell, A., Angers-Blondin, S., te Beest, M., Berner, L., Björk, R.G., Buchwal, A., Buras, A., Carbognani, M., Christie, K., Siegwart Collier, L., Cooper, E.J., Elberling, B., Eskelinen, A., Frei, E.R., Grau, O., Grogan, P., Hallinger, M., Heijmans, M.M.P.D., Hermanutz, L., Hudson, J., Johnstone, J.F., Hülber, K., Iturrate-Garcia, M., Iversen, C.M., Jaroszynska, F., Kaarlejärvi, E., Kulonen, A., Lamarque, L., Lantz, T.C., Lévesque, E., Little, C.J., Michelsen, A., Milbau, A., Nabe-Nielsen, J., Nielsen, S.S., Ninto, J.M., Oberbauer, S.F., Olofsson, J., Onipchenko, V.G., Petraglia, A., Rumpf, S.B., Shetti, R., Speed, J.D.M., Suding, K.N., Tape, K.D., Tomaselli, M., Trant, A.J., Treier, U.A., Tremblay, M., Venn, S., Vowles, T., Weijers, S., Wookey, P.A., Zamin, T., Bahn, M., Blonder, B., van Bodegom, P.M., Bond-Lambert, B., Campetella, G., Cerabolini, B.E.L., Chapin III, F.S., Craine, J., Dainese, M., Green, W., Jansen, S., Kleyer, M., Manning, P., Niinemets, Ü., Onoda, Y., Ozinga, W.A., Penuelas, J., Poschlod, P., Reich, P.B., Sandel, B., Schamp, B., Sheremetev, S., de Vries, F.T., 2020. Global plant trait relationships extend to the climatic extremes of the tundra biome. Nature Communications, 11, 1351. DOI: 10.1038/s41467-020-15014-4.

Thomas, H.J.D., Myers-Smith, I.H., Bjorkman, A.D., Elmendorf, S.C., Blok, D., Cornelissen, J.H.C., Forbes, B.C., Hollister, R.D., Normand, S., Prevéy, J.S., Rixen, C., Schaepman-Strub, G., Wilmking, M., Wipf, S., Cornwell, W.K., Kattge, J., Goetz, S.J., Guay, K.C., Alatalo, J.M., Anadon-Rosell, A., Angers-Blondin, S., Berner, L., Björk, R.G., Buchwal, A., Buras, A., Carbognani, M., Christie, K., Siegwart Collier, L., Cooper, E.J., Eskelinen, A., Frei, E.R., Grau, O., Grogan, P., Hallinger, M., Heijmans, M.M.P.D., Hermanutz, L., Hudson, J., Hülber, K., Iturrate-Garcia, M., Iversen, C.M., Jaroszynska, F., Johnstone, J.F., Kaarlejärvi, E., Kulonen, A., Lamarque, L., Lévesque, E., Little, C.J., Michelsen, A., Milbau, A., Nabe-Nielsen, J., Nielsen, S.S., Ninto, J.M., Oberbauer, S.F., Olofsson, J., Onipchenko, V.G., Petraglia, A., Rumpf, S.B., Semenchuk, P., Soudzilovskaia, N.A., Spasojevic, M.J., Speed, J.D.M., Tape, K.D., te Beest, M., Tomaselli, M., Trant, A.J., Treier, U.A., Venn, S., Vowles, T., Weijers, S., Zamin, T., Atkin, O.K., Bahn, M., Blonder, B., Campetella, G., Cerabolini, B.E.L., Chapin III, F.S., Dainese, M., de Vries, F.T., Díaz, S., Green, W., Jackson, R.B., Manning, P., Niinemets, Ü., Ozinga, W.A., Penuelas, J., Reich, P.B., Schamp, B., Sheremetev, S., van Bodegom, P.M., 2019. Traditional plant functional groups explain variation in economic but not size‐related traits across the tundra biome. Global Ecology and Biogeography, 28(2): 78-95. DOI: 10.1111/geb.12783.

Bjorkman, A.D., Myers-Smith, I.H., Elmendorf, S.C., Normand, S., Rüger, N., Beck, P.S.A., Blach-Overgaard, A., Blok, D., Cornelissen, J.H.C., Georges, D., Goetz, S.J., Guay, K.C., Henry, G.H.R., HilleRisLambers, J., Hollister, R.D., Karger, D.N., Kattge, J., Manning, P., Prevéy, J.S., Rixen, C., Schaepman-Strub, G., Thomas, H.J.D., Vellend, M., Wilmking, M., Wipf, S., Carbognani, M., Hermanutz, L., Lévesque, E., Molau, U., Petraglia, A., Soudzilovskaia, N.A., Spasojevic, M.J., Tomaselli, M., Vowles, T., Alatalo, J.M., Alexander, H.D., Anadon-Rosell, A., Angers-Blondin, S., te Beest, M., Berner, L., Björk, R.G., Buchwal, A., Buras, A., Christie, K., Cooper, E.J., Dullinger, S., Elberling, B., Eskelinen, A., Frei, E.R., Grau, O., Grogan, P., Hallinger, M., Harper, K., Heijmans, M.M.P.D., Hudson, J., Hülber, K., Iturrate-Garcia, M., Iversen, C.M., Jaroszynska, F., Johnstone, J.F., Jørgensen, R.H., Kaarlejärvi, E., Klady, R., Kuleza,., Kulonen, A., Lamarque, L., Lantz, T.C., Little, C.J., Speed, J.D.M., Michelsen, A., Milbau, A., Nabe-Nielsen, J., Nielsen, S.S., Ninto, J.M., Oberbauer, S.F., Olofsson, J., Onipchenko, V.G., Rumpf, S.B., Semenchuk, P., Shetti, R., Siegwart Collier, L., Street, L.E., Suding, K.N., Tape, K.D., Trant, A.J., Treier, U.A., Tremblay, J.-P., Tremblay, M., Venn, S., Weijers, S., Zamin, T., Boulanger-Lapointe, N., Gould, W.A., Hik, D.S., Hofgaard, A., Jónsdóttir, I.S., Jorgenson, J., Klein, J., Magnusson,., Tweedie, C., Wookey, P.A., Forbes, B.C., Bahn, M., Blonder, B., van Bodegom, P.M., Bond-Lambert, B., Campetella, G., Cerabolini, B.E.L., Chapin III, F.S., Cornwell, W.K., Craine, J., Dainese, M., de Vries, F.T., Díaz, S., Enquist, B.J., Green, W., Milla, R., Niinemets, Ü., Onoda, Y., Ordoñez, J.C., Ozinga, W.A., Penuelas, J., Poorter, H., Poschlod, P., Reich, P.B., Sandel, B., Schamp, B., Sheremetev, S., Weiher, E., 2018. Plant functional trait change across a warming tundra biome. Nature, 562: 57-62. DOI: 10.1038/s41586-018-0563-7.

Bjorkman, A.D., Myers-Smith, I.H., Elmendorf, S.C., Normand, S., Thomas, H.J.D., Alatalo, J.M., Alexander, H.D., Anadon-Rosell, A., Angers-Blondin, S., Bai, Y., Baruah, G., te Beest, M., Berner, L., Björk, R.G., Blok, D., Bruelheide, H., Buchwal, A., Buras, A., Carbognani, M., Christie, K., Collier, L.S., Cooper, E.J., Cornelissen, J.H.C., Dickinson, K.J.M., Dullinger, S., Elberling, B., Eskelinen, A., Forbes, B.C., Frei, E.R., Iturrate-Garcia, M., Good, M.K., Grau, O., Green, P., Greve, M., Grogan, P., Haider, S., Hájek, T., Hallinger, M., Happonen, K., Harper, K., Heijmans, M.M.P.D., Henry, G.H.R., Hermanutz, L., Hewitt, R.E., Hollister, R.D., Hudson, J., Hülber, K., Iversen, C.M., Jaroszynska, F., Jiménez‐Alfaro, B., Johnstone, J.F., Jørgensen, R.H., Kaarlejärvi, E., Klady, R., Klimešová, J., Korsten, A., Kuleza,., Kulonen, A., Lamarque, L., Lantz, T.C., Lavalle, A., Lembrechts, J.J., Lévesque, E., Little, C.J., Luoto, M., Macek, P., Mack, M.C., Mathakutha, R., Michelsen, A., Milbau, A., Molau, U., Morgan, J.W., Mörsdorf, M.A., Nabe-Nielsen, J., Nielsen, S.S., Ninto, J.M., Oberbauer, S.F., Olofsson, J., Onipchenko, V.G., Petraglia, A., Pickering, C., Prevéy, J.S., Rixen, C., Rumpf, S.B., Schaepman-Strub, G., Semenchuk, P., Shetti, R., Soudzilovskaia, N.A., Spasojevic, M.J., Speed, J.D.M., Street, L.E., Suding, K.N., Tape, K.D., Tomaselli, M., Trant, A.J., Treier, U.A., Tremblay, J.-P., Tremblay, M., Venn, S., Virkkala, A.-M., Vowels, T., Weijers, S., Wilmking, M., Wipf, S., Zamin, T., 2018. Tundra Trait Team: A database of plant traits spanning the tundra biome. Global Ecology and Biogeography, 27(12): 1402-1411. DOI: 10.1111/geb.12821.

Perreault, N., Lévesque, E., Fortier, D., Lamarque, L., 2016. Thermo-erosion gullies boost the transition from wet to mesic tundra vegetation. Biogeosciences, 13(4): 1237-1253. DOI: 10.5194/bg-13-1237-2016.

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