Françoise Cardou, Alison D. Munson, Laura Boisvert-Marsh, Madhur Anand, André Arsenault, F. Wayne Bell, Yves Bergeron, Isabelle Boulangeat, Nicole J. Fenton, Sylvain Delagrange, Dominique Gravel, Benoît Hamel, François Hébert, Jill F. Johnstone, Bright B. Kumordzi, S. Ellen Macdonald, Azim Mallik, Anne C. S. McIntosh, Jennie R. McLaren, Christian Messier, Dave Morris, Bill Shipley, Luc Sirois, Nelson Thiffault, Isabelle Aubin. Above-and belowground drivers of intraspecific trait variability across subcontinental gradients for five ubiquitous forest plants in North America 2022. Journal of Ecology 110(7):1590-1605
DOI : 10.1111/1365-2745.13894
Intraspecific trait variability (ITV) provides the material for species' adaptation to environmental changes. To advance our understanding of how ITV can contribute to species' adaptation to a wide range of environmental conditions, we studied five widespread understorey forest species exposed to both continental-scale climate gradients, and local soil and disturbance gradients. We investigated the environmental drivers of between-site leaf and root trait variation, and tested whether higher between-site ITV was associated with increased trait sensitivity to environmental variation (i.e. environmental fit). We measured morphological (specific leaf area: SLA, specific root length: SRL) and chemical traits (Leaf and Root N, P, K, Mg, Ca) of five forest understorey vascular plant species at 78 sites across Canada. A total of 261 species-by-site combinations spanning ~4300 km were sampled, capturing important abiotic and biotic environmental gradients (neighbourhood composition, canopy structure, soil conditions, climate). We used multivariate and univariate linear mixed models to identify drivers of ITV and test the association of between-site ITV with environmental fit. Between-site ITV of leaf traits was primarily driven by canopy structure and climate. Comparatively, environmental drivers explained only a small proportion of variability in root traits: these relationships were trait specific and included soil conditions (Root P), canopy structure (Root N) and neighbourhood composition (SRL, Root K). Between-site ITV was associated with increased environmental fit only for a minority of traits, primarily in response to climate (SLA, Leaf N, SRL). Synthesis. By studying how ITV is structured along environmental gradients among species adapted to a wide range of conditions, we can begin to understand how individual species might respond to environmental change. Our results show that generalisable trait–environment relationships occur primarily aboveground, and only accounted for a small proportion of variability. For our group of species with broad ecological niches, variability in traits was only rarely associated with higher environmental fit, and primarily along climatic gradients. These results point to promising research avenues on the various ways in which trait variation can affect species' performance along different environmental gradients.
Bright B. Kumordzi, Isabelle Aubin, Françoise Cardou, Bill Shipley, Cyrille Violle, Jill Johnstone, Madur Anand, André Arsenault, F. Wayne Bell, Yves Bergeron, Isabelle Boulangeat, Maxime Brousseau, Sylvain Delagrange, Nicole J. Fenton, Dominique Gravel, Ellen MacDonald, Benoît Hamel, Morgane Higelin, Louis De Grandpré, François Hébert, Nathalie Isabel, Azim Mallik, Anne C.S. McIntosh, Jennie R. McLaren, Christian Messier, Dave M. Morris, Nelson Thiffault, Jean-Pierre Tremblay, Alison Munson. Geographic scale and disturbance influence intraspecific trait
variability in leaves and roots of North American understorey
plants. 2019. Functional Ecology 33(9):1771-1784
DOI : 10.1111/1365-2435.13402
- Considering intraspecific trait variability (ITV) in ecological studies has improved our understanding of species persistence and coexistence. These advances are based on the growing number of leaf ITV studies over local gradients, but logistical constraints have prevented a solid examination of ITV in root traits or at scales reflecting species’ geographic ranges.
- We compared the magnitude of ITV in above? and below?ground plant organs across three spatial scales (biophysical region, locality and plot). We focused on six understorey species (four herbs and two shrubs) that occur both in disturbed and undisturbed habitats across boreal and temperate Canadian forests. We aimed to document ITV structure over broad ecological and geographical scales by asking: (a) What is the breadth of ITV across species range?scale? (b) What proportion of ITV is captured at different spatial scales, particularly when local scale disturbances are considered? and (c) Is the variance structure consistent between analogous leaf and root traits, and between morphological and chemical traits?
- Following standardized methods, we sampled 818 populations across 79 forest plots simultaneously, including disturbed and undisturbed stands, spanning four biophysical regions (~5,200 km). Traits measured included specific leaf area (SLA), specific root length (SRL) and leaf and root nutrient concentrations (N, P, K, Mg, Ca). We used variance decomposition techniques to characterize ITV structure across scales.
- Our results show that an important proportion of ITV occurred at the local scale when sampling included contrasting environmental conditions resulting from local disturbance. A certain proportion of the variability in both leaf and root traits remained unaccounted for by the three sampling scales included in the design (36% on average), with the largest amount for SRL (54%). Substantial differences in magnitude of ITV were found among the six species, and between analogous traits, suggesting that trait distribution was influenced by species strategy and reflects the extent of understorey environment heterogeneity.
- Even for species with broad geographical distributions, a large proportion of within?species trait variability can be captured by sampling locally across ecological gradients. This has practical implications for sampling design and trait selection for both local studies and continental?scale modelling.
Helge Bruelheide, Jürgen Dengler, Borja Jiménez-Alfaro, Oliver Purschke, Stephan M. Hennekens, Milan Chytrý, Valério D. Pillar, Florian Jansen, Jens Kattge, Brody Sandel, Isabelle Aubin, Idoia Biurrun, Richard Field, Sylvia Haider, Ute Jandt, Jonathan Lenoir, Robert K. Peet, Gwendolyn Peyre, Francesco Maria Sabatini, Marco Schmidt, Franziska Schrodt, Marten Winter, Svetlana Acic, Emiliano Agrillo, Miguel Alvarez, Didem Ambarli, Pierangela Angelini, Iva Apostolova, Mohammed A. S. Arfin Khan, Elise Arnst, Fabio Attorre, Christopher Baraloto, Michael Beckmann, Christian Berg, Yves Bergeron, Erwin Bergmeier, Anne D. Bjorkman, Viktoria Bondareva, Peter Borchardt, Zoltán Botta-Dukát, Brad Boyle, Amy Breen, Henry Brisse, Chaeho Byun, Marcelo R. Cabido, Laura Casella, Luis Cayuela, Tomáš Cerný, Victor Chepinoga, János Csiky, Michael Curran, Renata Cušterevska, Zora Dajic Stevanovic, Els De Bie, Patrice de Ruffray, Michele De Sanctis, Panayotis Dimopoulos, Stefan Dressler, Rasmus Ejrnæs, Mohamed Abd El-Rouf Mousa El-Sheikh, Brian Enquist, Jörg Ewald, Jaime Fagúndez, Manfred Finckh, Xavier Font, Estelle Forey, Georgios Fotiadis, Itziar García-Mijangos, André Luis de Gasper, Valentin Golub, Alvaro G. Gutierrez, Mohamed Z. Hatim, Tianhua He, Pedro Higuchi, Dana Holubová, Norbert Hölzel, Jürgen Homeier, Adrian Indreica, Deniz Isik Gürsoy, Steven Jansen, John Janssen, Birgit Jedrzejek, Martin Jiroušek, Norbert Jürgens, Zygmunt Kacki, Ali Kavgaci, Elizabeth Kearsley, Michael Kessler, Ilona Knollová, Vitaliy Kolomiychuk, Andrey Korolyuk, Maria Kozhevnikova, Lukasz Kozub, Daniel Krstonošic, Hjalmar Kühl, Ingolf Kühn, Anna Kuzemko, Filip Küzmic, Flavia Landucci, Michael T. Lee, Aurora Levesley, Ching-Feng Li, Hongyan Liu, Gabriela Lopez-Gonzalez, Tatiana Lysenko, Armin Macanovic, Parastoo Mahdavi, Peter Manning, Corrado Marcenò, Vassiliy Martynenko, Maurizio Mencuccini, Vanessa Minden, Jesper Erenskjold Moeslund, Marco Moretti, Jonas V. Müller, Jérôme Munzinger, Ülo Niinemets, Marcin Nobis, Jalil Noroozi, Arkadiusz Nowak, Viktor Onyshchenko, Gerhard E. Overbeck, Wim A. Ozinga, Anibal Pauchard, Hristo Pedashenko, Josep Peñuelas, Aaron Pérez-Haase, Tomáš Peterka, Petr Petrík, Oliver L. Phillips, Vadim Prokhorov, Valerijus Rašomavicius, Rasmus Revermann, John Rodwell, Eszter Ruprecht, Solvita Rusina, Cyrus Samimi, Joop H.J. Schaminée, Ute Schmiedel, Jozef Šibík, Urban Šilc, Željko Škvorc, Anita Smyth, Tenekwetche Sop, Desislava Sopotlieva, Ben Sparrow, Zvjezdana Stancic, Jens-Christian Svenning, Grzegorz Swacha, Zhiyao Tang, Ioannis Tsiripidis, Pavel Dan Turtureanu, Emin Ugurlu, Domas Uogintas, Milan Valachovic, Kim André Vanselow, Yulia Vashenyak, Kiril Vassilev, Eduardo Vélez-Martin, Roberto Venanzoni, Alexander Christian Vibrans, Cyrille Violle, Risto Virtanen, Henrik von Wehrden, Viktoria Wagner, Donald A. Walker, Desalegn Wana, Evan Weiher, Karsten Wesche, Timothy Whitfeld, Wolfgang Willner, Susan Wiser, Thomas Wohlgemuth, Sergey Yamalov, Georg Zizka, Andrei Zverev. sPlot – A new tool for global vegetation analyses 2019. J. Veg. Sci. 30(2):161-186
DOI : 10.1111/jvs.12710
Vegetation?plot records provide information on the presence and cover or abundance of plants co?occurring in the same community. Vegetation?plot data are spread across research groups, environmental agencies and biodiversity research centers and, thus, are rarely accessible at continental or global scales. Here we present the sPlot database, which collates vegetation plots worldwide to allow for the exploration of global patterns in taxonomic, functional and phylogenetic diversity at the plant community level.
sPlot version 2.1 contains records from 1,121,244 vegetation plots, which comprise 23,586,216 records of plant species and their relative cover or abundance in plots collected worldwide between 1885 and 2015. We complemented the information for each plot by retrieving climate and soil conditions and the biogeographic context (e.g., biomes) from external sources, and by calculating community?weighted means and variances of traits using gap?filled data from the global plant trait database TRY. Moreover, we created a phylogenetic tree for 50,167 out of the 54,519 species identified in the plots. We present the first maps of global patterns of community richness and community?weighted means of key traits.
The availability of vegetation plot data in sPlot offers new avenues for vegetation analysis at the global scale.
Cynthia Patry, Isabelle Aubin, Daniel Kneeshaw, Christian Messier. Intensive forestry filters understory plant traits over time and space in boreal forests. 2017. Forestry 90(3):436-444
DOI : 10.1093/forestry/cpx002
Because of their scarcity, protected areas alone cannot maintain biodiversity. Therefore, it is necessary to create conditions appropriate for plants and wildlife in managed landscapes. We compared the effects of different intensities of forest management on functional responses of vascular understory plants using the fourth-corner method. We analysed functional community composition along a management gradient that spanned semi-natural forests to extensively managed forests (naturally regenerated cuts) to intensively managed forests (planted forests) in Canada. Results showed trait filtering along the gradient of forest management intensity. In natural and extensively managed forests, where forest retention was high in time and space, persistence traits (e.g. perennial geophytes or chamaephytes, non-leafy stem foliage structure) were maintained. At the opposite end of the gradient, in intensively managed plantations where forest retention elements (e.g. amount of dead wood) were reduced, trait filtering led to species associated with colonization, such as tall species with limited lateral extension. These results suggest that intensive forestry conducted over a large extent may change the functional composition of understory plants.
Isabelle Aubin, Marilou Beaudet, Christian Messier. Light extinction coefficients specific to the understory vegetation of the southern boreal forest, Quebec. 2000. Can. J. For. Res. 30(1):168-177.
DOI : 10.1139/cjfr-30-1-168
This study was conducted in six different forest types in Abitibi, Que., (i) to identify the factors that most influence understory light transmission in the southern boreal forest and (ii) to develop light extinction coefficients (k), which could be used to simulate light transmission in the understory. Light availability and understory vegetation (cover, composition, vertical distribution, and leaf area index) were characterized within three strata (0.05-5 m) in a total of 180 quadrats. Calculated k values were based on measured light availability and leaf area index. These values varied among forest types, strata, understory vegetation types, and cover in the upper stratum. The highest k values were generally associated with a dense stratum of Acer spicatum Lam. We developed five sets of k values based on the factors that most affected light transmission. Measured transmission (Tm) was compared with transmission predicted (Tp) from each set of k values. Light transmission predicted using a single k value (mean k = 0.54) underestimated Tm. More accurate predictions were obtained when we used the other four sets of k values. Our results indicate that, in the southern boreal forest, the understory vegetation can be quite heterogeneous and patterns of light transmission cannot be accurately simulated using a unique k value. However, the various sets of k values developed in this study could be used in prediction models of forest dynamics to obtain relatively good predictions of understory light extinction in forest types similar to the ones studied here.
©2000 NRC Canada
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Isabelle Aubin. Végétation de sous-bois et disponibilité de la lumière dans la forêt boréale du sud-ouest québécois. 1999. Mémoire de maîtrise en biologie, Université du Québec à Montréal.