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Poch P, Poulin E, Pérez MF, Peralta G, Hinojosa LF. Spatial patterns of congruence or mismatch between taxonomic, functional, and phylogenetic diversity and endemism of perennial flora along the aridity gradient of Chile. FRONTIERS IN PLANT SCIENCE 2024; 15:1418673. [PMID: 39280949 PMCID: PMC11392779 DOI: 10.3389/fpls.2024.1418673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 08/07/2024] [Indexed: 09/18/2024]
Abstract
Introduction Understanding the relationships between taxonomic, functional, and phylogenetic diversity and endemism across environmental gradients is essential for elucidating the eco-evolutionary mechanisms that shape local plant communities. Methods A database was compiled from field surveys, national herbarium records, and virtual records of perennial plant specimens collected in the aridity gradient of northern Chile, between 18 and 32°S. A large-scale dated phylogeny of available perennial plants was used, and 11 functional traits were selected to construct a dendrogram using the Unweighted Pair-Group Method with Arithmetic Mean (UPGMA) method for the species present in our database. We calculated spatial patterns of a-diversity, including taxonomic (TD), functional (FD), and phylogenetic (PD) diversity, as well as weighted (WE), functional (FE), and phylogenetic (PE) endemism. We used multiscale geographically weighted regression (MGWR) to identify spatial congruencies and discrepancies among these dimensions and to test different eco-evolutionary processes. Results The diversity indices TD, FD and PD showed similar geographic patterns (R2 > 0.93), with lower diversity observed in absolute desert regions. The pattern of weighted endemism (WE) showed a weak association with functional endemism (FE) and phylogenetic endemism (PE) (local R2 < 0.48). The regions with lower FD or PD than expected given the TD (i.e. FD WE and PE>WE), they are found in arid, high Andean and transitional zones, at different altitudes, which would indicate a greater presence of phylogenetic lineages and species with morpho-functional traits related to extreme environmental conditions and transitional biomes (arid-semiarid). Discussion These spatial discrepancies suggest different eco-evolutionary drivers between the dimensions of diversity and endemism (taxonomic, functional, and phylogenetic). Areas of high diversity and high endemism do not necessarily coincide, and both should be addressed by conservation efforts.
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Affiliation(s)
- Paola Poch
- Institute of Ecology and Biodiversity (IEB), Santiago, Chile
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras, Santiago, Chile
| | - Elie Poulin
- Institute of Ecology and Biodiversity (IEB), Santiago, Chile
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras, Santiago, Chile
| | - María Fernanda Pérez
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Gioconda Peralta
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Luis Felipe Hinojosa
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras, Santiago, Chile
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2
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Leverett A, Borland AM, Inge EJ, Hartzell S. Low internal air space in plants with crassulacean acid metabolism may be an anatomical spandrel. ANNALS OF BOTANY 2023; 132:811-817. [PMID: 37622678 PMCID: PMC10799988 DOI: 10.1093/aob/mcad109] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/19/2023] [Accepted: 08/17/2023] [Indexed: 08/26/2023]
Abstract
Crassulacean acid metabolism (CAM) is a photosynthetic adaptation found in at least 38 plant families. Typically, the anatomy of CAM plants is characterized by large photosynthetic cells and a low percentage of leaf volume consisting of internal air space (% IAS). It has been suggested that reduced mesophyll conductance (gm) arising from low % IAS benefits CAM plants by preventing the movement of CO2 out of cells and ultimately minimizing leakage of CO2 from leaves into the atmosphere during day-time decarboxylation. Here, we propose that low % IAS does not provide any adaptive benefit to CAM plants, because stomatal closure during phase III of CAM will result in internal concentrations of CO2 becoming saturated, meaning low gm will not have any meaningful impact on the flux of gases within leaves. We suggest that low % IAS is more likely an indirect consequence of maximizing the cellular volume within a leaf, to provide space for the overnight storage of malic acid during the CAM cycle.
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Affiliation(s)
- Alistair Leverett
- School of Life Sciences, University of Essex, Wivenhoe Campus, Essex, CO4 3SQ, UK
- Department of Plant Sciences, University of Cambridge, Downing St., Cambridge, CB2 3EA, UK
| | - Anne M Borland
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Emma J Inge
- School of Life Sciences, University of Essex, Wivenhoe Campus, Essex, CO4 3SQ, UK
| | - Samantha Hartzell
- Department of Civil and Environmental Engineering, Portland State University, 1930 SW 124 Ave., Portland, OR, USA
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3
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Streit RP, Bellwood DR. Moving beyond the one true trait. Trends Ecol Evol 2023; 38:1014-1015. [PMID: 37659888 DOI: 10.1016/j.tree.2023.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 08/10/2023] [Indexed: 09/04/2023]
Affiliation(s)
- Robert P Streit
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia.
| | - David R Bellwood
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia
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Barkaoui K, Volaire F. Drought survival and recovery in grasses: Stress intensity and plant-plant interactions impact plant dehydration tolerance. PLANT, CELL & ENVIRONMENT 2023; 46:1489-1503. [PMID: 36655754 DOI: 10.1111/pce.14543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 01/07/2023] [Accepted: 01/16/2023] [Indexed: 06/17/2023]
Abstract
Plant dehydration tolerance confers drought survival in grasses, but the mortality thresholds according to soil water content (SWC), vapour pressure deficit (VPD) and plant-plant interactions are little explored. We compared the dehydration dynamics of leaf meristems, which are the key surviving organs, plant mortality, and recovery of Mediterranean and temperate populations of two perennial grass species, Dactylis glomerata and Festuca arundinacea, grown in monocultures and mixtures under a low-VPD (1.5 kPa) versus a high-VPD drought (2.2 kPa). The lethal drought index (LD50 ), that is, SWC associated with 50% plant mortality, ranged from 2.87% (ψs = -1.68 MPa) to 2.19% (ψs = -4.47 MPa) and reached the lowest values under the low-VPD drought. Populations of D. glomerata were more dehydration-tolerant (lower LD50 ), survived and recovered better than F. arundinacea populations. Plant-plant interactions modified dehydration tolerance and improved post-drought recovery in mixtures compared with monocultures. Water content as low as 20.7%-36.1% in leaf meristems allowed 50% of plants to survive. We conclude that meristem dehydration causes plant mortality and that drought acclimation can increase dehydration tolerance. Genetic diversity, acclimation and plant-plant interactions are essential sources of dehydration tolerance variability to consider when predicting drought-induced mortality.
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Affiliation(s)
- Karim Barkaoui
- CIRAD, UMR ABSys, F-34398 Montpellier, France
- ABSys, Univ Montpellier, CIHEAM-IAMM, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Florence Volaire
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, INRAE, Montpellier, France
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5
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Rypel AL. Ecosystem size filters life-history strategies to shape community assembly in lakes. J Anim Ecol 2023. [PMID: 37081674 DOI: 10.1111/1365-2656.13925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 03/13/2023] [Indexed: 04/22/2023]
Abstract
Enhancing understanding of community assembly rules hinges on shared conceptualizations that operate across scales and levels of ecological organization. Knowledge of the biogeography of life-history strategies is especially limited but crucial for building fundamental information on the relationships between trait diversity and species richness. The goals of this study were to (i) demonstrate how life histories can be classified using a previously identified triangular continuum of evolutionary trade-offs; (ii) test whether spatial and temporal heterogeneity in species abundances is linked to life-history strategy; (iii) compare species-area relationships across the primary life-history strategist groups and (iv) explore how species life-history niche spaces are shaped by ecosystem size and landscape architecture. Fish communities were sampled in 40 lakes that varied widely in volume; 11 lakes were sampled annually for 28 or 42 years. Seventy-one species were classified as equilibrium, periodic or opportunistic strategists, and species-area curves were quantified and compared among strategy types. As predicted by life-history theory, relative abundances of opportunistic strategists were extremely variable over space and time, whereas abundances of equilibrium and periodic strategists were more stable. Small lakes were often dominated by only one species, usually an opportunistic strategist. Species richness increased with ecosystem size, but larger ecosystems were increasingly inhabited by equilibrium, and then, periodic strategists. Richness of periodic species increased with ecosystem size at a faster rate compared with opportunistic species showing that colonization-extinction points fundamentally vary by strategy. Similarly, life-history niche space increased with ecosystem size in accord with species-area relationships but showed saturation behaviour. Niche space became increasingly crowded in large lakes, particularly in lakes with higher hydrologic connectance. Ecosystem size mediates the assembly of communities through effects on environmental stability, hydrology and life-history filtering. This finding provides novel insights into community assembly at multiple scales and has broad conservation applications. Because ecosystem size filters towards orthogonal and inverse life histories, conservation actions (e.g. fish stockings) that do not consider life-history and community filtering rules will probably fail.
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Affiliation(s)
- Andrew L Rypel
- Department of Wildlife, Fish & Conservation Biology, University of California Davis, Davis, California, USA
- Center for Watershed Sciences, University of California Davis, Davis, California, USA
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Aspinwall MJ, Blackman CJ, Maier C, Tjoelker MG, Rymer PD, Creek D, Chieppa J, Griffin-Nolan RJ, Tissue DT. Aridity drives clinal patterns in leaf traits and responsiveness to precipitation in a broadly distributed Australian tree species. PLANT-ENVIRONMENT INTERACTIONS (HOBOKEN, N.J.) 2023; 4:70-85. [PMID: 37288162 PMCID: PMC10243541 DOI: 10.1002/pei3.10102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 02/08/2023] [Accepted: 02/16/2023] [Indexed: 06/09/2023]
Abstract
Aridity shapes species distributions and plant growth and function worldwide. Yet, plant traits often show complex relationships with aridity, challenging our understanding of aridity as a driver of evolutionary adaptation. We grew nine genotypes of Eucalyptus camaldulensis subsp. camaldulensis sourced from an aridity gradient together in the field for ~650 days under low and high precipitation treatments. Eucalyptus camaldulesis is considered a phreatophyte (deep-rooted species that utilizes groundwater), so we hypothesized that genotypes from more arid environments would show lower aboveground productivity, higher leaf gas-exchange rates, and greater tolerance/avoidance of dry surface soils (indicated by lower responsiveness) than genotypes from less arid environments. Aridity predicted genotype responses to precipitation, with more arid genotypes showing lower responsiveness to reduced precipitation and dry surface conditions than less arid genotypes. Under low precipitation, genotype net photosynthesis and stomatal conductance increased with home-climate aridity. Across treatments, genotype intrinsic water-use efficiency and osmotic potential declined with increasing aridity while photosynthetic capacity (Rubisco carboxylation and RuBP regeneration) increased with aridity. The observed clinal patterns indicate that E. camaldulensis genotypes from extremely arid environments possess a unique strategy defined by lower responsiveness to dry surface soils, low water-use efficiency, and high photosynthetic capacity. This strategy could be underpinned by deep rooting and could be adaptive under arid conditions where heat avoidance is critical and water demand is high.
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Affiliation(s)
- Michael J Aspinwall
- Hawkesbury Institute for the Environment Western Sydney University Penrith New South Wales Australia
- College of Forestry and Wildlife Sciences Auburn University Auburn Alabama USA
- Formation Environmental LLC Sacramento California USA
| | - Chris J Blackman
- Hawkesbury Institute for the Environment Western Sydney University Penrith New South Wales Australia
- ARC Centre of Excellence for Plant Success in Nature and Agriculture School of Natural Sciences, University of Tasmania Hobart Australia
| | - Chelsea Maier
- Hawkesbury Institute for the Environment Western Sydney University Penrith New South Wales Australia
| | - Mark G Tjoelker
- Hawkesbury Institute for the Environment Western Sydney University Penrith New South Wales Australia
| | - Paul D Rymer
- Hawkesbury Institute for the Environment Western Sydney University Penrith New South Wales Australia
| | - Danielle Creek
- Hawkesbury Institute for the Environment Western Sydney University Penrith New South Wales Australia
- Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life Sciences (NMBU) Ås Norway
| | - Jeff Chieppa
- College of Forestry and Wildlife Sciences Auburn University Auburn Alabama USA
| | | | - David T Tissue
- Hawkesbury Institute for the Environment Western Sydney University Penrith New South Wales Australia
- Global Centre for Land Based Innovation Western Sydney University Richmond New South Wales Australia
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Volaire F, Barkaoui K, Grémillet D, Charrier G, Dangles O, Lamarque LJ, Martin-StPaul N, Chuine I. Is a seasonally reduced growth potential a convergent strategy to survive drought and frost in plants? ANNALS OF BOTANY 2023; 131:245-254. [PMID: 36567631 PMCID: PMC9992932 DOI: 10.1093/aob/mcac153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 12/14/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND Plants have adapted to survive seasonal life-threatening frost and drought. However, the timing and frequency of such events are impacted by climate change, jeopardizing plant survival. Understanding better the strategies of survival to dehydration stress is therefore timely and can be enhanced by the cross-fertilization of research between disciplines (ecology, physiology), models (woody, herbaceous species) and types of stress (drought, frost). SCOPE We build upon the 'growth-stress survival' trade-off, which underpins the identification of global plant strategies across environments along a 'fast-slow' economics spectrum. Although phenological adaptations such as dormancy are crucial to survive stress, plant global strategies along the fast-slow economic spectrum rarely integrate growth variations across seasons. We argue that the growth-stress survival trade-off can be a useful framework to identify convergent plant ecophysiological strategies to survive both frost and drought. We review evidence that reduced physiological activity, embolism resistance and dehydration tolerance of meristematic tissues are interdependent strategies that determine thresholds of mortality among plants under severe frost and drought. We show that complete dormancy, i.e. programmed growth cessation, before stress occurrence, minimizes water flows and maximizes dehydration tolerance during seasonal life-threatening stresses. We propose that incomplete dormancy, i.e. the programmed reduction of growth potential during the harshest seasons, could be an overlooked but major adaptation across plants. Quantifying stress survival in a range of non-dormant versus winter- or summer-dormant plants, should reveal to what extent incomplete to complete dormancy could represent a proxy for dehydration tolerance and stress survival. CONCLUSIONS Our review of the strategies involved in dehydration stress survival suggests that winter and summer dormancy are insufficiently acknowledged as plant ecological strategies. Incorporating a seasonal fast-slow economics spectrum into global plant strategies improves our understanding of plant resilience to seasonal stress and refines our prevision of plant adaptation to extreme climatic events.
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Affiliation(s)
- Florence Volaire
- CEFE, Université Montpellier, INRAE, CNRS, EPHE, IRD, F-34090 Montpellier, France
| | - Karim Barkaoui
- CIRAD, UMR ABSys, F-34398 Montpellier, France
- ABSys, Université F-34060 Montpellier, CIHEAM-IAMM, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - David Grémillet
- CEFE, Université Montpellier, CNRS, EPHE, IRD, F-34090 Montpellier, France
- Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, South Africa
| | - Guillaume Charrier
- Université Clermont Auvergne, INRAE, PIAF, F-63000 Clermont Ferrand, France
| | - Olivier Dangles
- CEFE, Université Montpellier, CNRS, EPHE, IRD, F-34090 Montpellier, France
| | - Laurent J Lamarque
- Département des Sciences de l’Environnement, Université du Québec à Trois-Rivières, Trois-Rivières, QC, G9A 5H7, Canada
| | - Nicolas Martin-StPaul
- INRAE, URFM, Domaine Saint Paul, Centre de recherche PACA, 228 route de l’Aérodrome, CS 40509, Domaine Saint-Paul, Site Agroparc, France
| | - Isabelle Chuine
- CEFE, Université Montpellier, CNRS, EPHE, IRD, F-34090 Montpellier, France
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8
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Streit RP, Bellwood DR. To harness traits for ecology, let’s abandon ‘functionality’. Trends Ecol Evol 2022; 38:402-411. [PMID: 36522192 DOI: 10.1016/j.tree.2022.11.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 11/16/2022] [Accepted: 11/21/2022] [Indexed: 12/14/2022]
Abstract
Traits are measurable features of organisms. Functional traits aspire to more. They quantify an organism's ecology and, ultimately, predict ecosystem functions based on local communities. Such predictions are useful, but only if 'functional' really means 'ecologically relevant'. Unfortunately, many 'functional' traits seem to be characterized primarily by availability and implied importance - not by their ecological information content. Better traits are needed, but a prevailing trend is to 'functionalize' existing traits. The key may be to invert the process, that is, to identify functions of interest first and then identify traits as quantifiable proxies. We propose two distinct, yet complementary, perspectives on traits and provide a 'taxonomy of traits', a conceptual compass to navigate the diverse applications of traits in ecology.
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Veeken A, Santos MJ, McGowan S, Davies AL, Schrodt F. Pollen-based reconstruction reveals the impact of the onset of agriculture on plant functional trait composition. Ecol Lett 2022; 25:1937-1951. [PMID: 35816121 PMCID: PMC9544184 DOI: 10.1111/ele.14063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 05/17/2022] [Accepted: 05/28/2022] [Indexed: 11/26/2022]
Abstract
The onset of agriculture improved the capacity of ecosystems to produce food, but inadvertently altered other vital ecosystem functions. Plant traits play a central role in determining ecosystem properties, therefore we investigated how the onset of agriculture in Europe changed plant trait composition using 78 pollen records. Using a novel Bayesian approach for reconstructing plant trait composition from pollen records, we provide a robust method that can account for trait variability within pollen types. We estimate an overall four-fold decrease in plant size through agriculture and associated decreases in leaf and seed size. We show an increase in niche space towards the resource-acquisitive end of the leaf economic spectrum. Decreases in leaf phosphorus might have been caused by nutrient depletion through grazing and burning. Our results show that agriculture, from its start, has likely been gradually impacting biogeochemical cycles through altered vegetation composition.
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Affiliation(s)
| | - Maria J Santos
- Department of Geography, University of Zürich, Zürich, Switzerland
| | - Suzanne McGowan
- School of Geography, University of Nottingham, Nottingham, UK.,Aquatic Ecology Department, Netherlands Institute of Ecology, Wageningen, the Netherlands
| | - Althea L Davies
- School of Geography and Sustainable Development, University of St Andrews, St Andrews, UK
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Djemiel C, Maron PA, Terrat S, Dequiedt S, Cottin A, Ranjard L. Inferring microbiota functions from taxonomic genes: a review. Gigascience 2022; 11:giab090. [PMID: 35022702 PMCID: PMC8756179 DOI: 10.1093/gigascience/giab090] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/02/2021] [Accepted: 12/02/2021] [Indexed: 12/13/2022] Open
Abstract
Deciphering microbiota functions is crucial to predict ecosystem sustainability in response to global change. High-throughput sequencing at the individual or community level has revolutionized our understanding of microbial ecology, leading to the big data era and improving our ability to link microbial diversity with microbial functions. Recent advances in bioinformatics have been key for developing functional prediction tools based on DNA metabarcoding data and using taxonomic gene information. This cheaper approach in every aspect serves as an alternative to shotgun sequencing. Although these tools are increasingly used by ecologists, an objective evaluation of their modularity, portability, and robustness is lacking. Here, we reviewed 100 scientific papers on functional inference and ecological trait assignment to rank the advantages, specificities, and drawbacks of these tools, using a scientific benchmarking. To date, inference tools have been mainly devoted to bacterial functions, and ecological trait assignment tools, to fungal functions. A major limitation is the lack of reference genomes-compared with the human microbiota-especially for complex ecosystems such as soils. Finally, we explore applied research prospects. These tools are promising and already provide relevant information on ecosystem functioning, but standardized indicators and corresponding repositories are still lacking that would enable them to be used for operational diagnosis.
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Affiliation(s)
- Christophe Djemiel
- Agroécologie, AgroSup Dijon, INRAE, Université de Bourgogne, Université de Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Pierre-Alain Maron
- Agroécologie, AgroSup Dijon, INRAE, Université de Bourgogne, Université de Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Sébastien Terrat
- Agroécologie, AgroSup Dijon, INRAE, Université de Bourgogne, Université de Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Samuel Dequiedt
- Agroécologie, AgroSup Dijon, INRAE, Université de Bourgogne, Université de Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Aurélien Cottin
- Agroécologie, AgroSup Dijon, INRAE, Université de Bourgogne, Université de Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Lionel Ranjard
- Agroécologie, AgroSup Dijon, INRAE, Université de Bourgogne, Université de Bourgogne Franche-Comté, F-21000 Dijon, France
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12
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Manzi OJL, Bellifa M, Ziegler C, Mihle L, Levionnois S, Burban B, Leroy C, Coste S, Stahl C. Drought stress recovery of hydraulic and photochemical processes in Neotropical tree saplings. TREE PHYSIOLOGY 2022; 42:114-129. [PMID: 34302178 DOI: 10.1093/treephys/tpab092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 07/16/2021] [Indexed: 06/13/2023]
Abstract
Climate models predict an increase in the severity and the frequency of droughts. Tropical forests are among the ecosystems that could be highly impacted by these droughts. Here, we explore how hydraulic and photochemical processes respond to drought stress and re-watering. We conducted a pot experiment on saplings of five tree species. Before the onset of drought, we measured a set of hydraulic traits, including minimum leaf conductance, leaf embolism resistance and turgor loss point. During drought stress, we monitored traits linked to leaf hydraulic functioning (leaf water potential (ψmd) and stomatal conductance (gs)) and traits linked to leaf photochemical functioning (maximum quantum yield of photosystem II (Fv/Fm) and maximum electron transport rate (ETRmax)) at different wilting stages. After re-watering, the same traits were measured after 3, 7 and 14 days. Hydraulic trait values decreased faster than photochemical trait values. After re-watering, the values of the four traits recovered at different rates. Fv/Fm recovered very fast close to their initial values only 3 days after re-watering. This was followed by ETRmax, Ψmd and gs. Finally, we show that species with large stomatal and leaf safety margin and low πtlp are not strongly impacted by drought, whereas they have a low recovery on photochemical efficiency. These results demonstrate that πtlp, stomatal and leaf safety margin are a good indicators of plant responses to drought stress and also to recovery for photochemical efficiency.
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Affiliation(s)
- Olivier Jean Leonce Manzi
- UMR EcoFoG, CNRS, CIRAD, INRAE, AgroParisTech, Université des Antilles, Université de Guyane, 97310 Kourou, France
- Integrated Polytechnic Regional College-Kitabi, Rwanda Polytechnic, PO Box 330, Huye, Rwanda
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, SE-40530 Gothenburg, Sweden
| | - Maxime Bellifa
- UMR EcoFoG, CNRS, CIRAD, INRAE, AgroParisTech, Université des Antilles, Université de Guyane, 97310 Kourou, France
| | - Camille Ziegler
- UMR EcoFoG, CNRS, CIRAD, INRAE, AgroParisTech, Université des Antilles, Université de Guyane, 97310 Kourou, France
- Université de Lorraine, AgroParisTech, INRAE, UMR Silva, 54000 Nancy, France
| | - Louis Mihle
- UMR EcoFoG, CNRS, CIRAD, INRAE, AgroParisTech, Université des Antilles, Université de Guyane, 97310 Kourou, France
| | - Sébastien Levionnois
- UMR EcoFoG, CNRS, CIRAD, INRAE, AgroParisTech, Université des Antilles, Université de Guyane, 97310 Kourou, France
- AMAP, Univ Montpellier, CIRAD, CNRS, INRAE, IRD, 34000 Montpellier, France
| | - Benoit Burban
- UMR EcoFoG, CNRS, CIRAD, INRAE, AgroParisTech, Université des Antilles, Université de Guyane, 97310 Kourou, France
| | - Céline Leroy
- UMR EcoFoG, CNRS, CIRAD, INRAE, AgroParisTech, Université des Antilles, Université de Guyane, 97310 Kourou, France
- AMAP, Univ Montpellier, CIRAD, CNRS, INRAE, IRD, 34000 Montpellier, France
| | - Sabrina Coste
- UMR EcoFoG, CNRS, CIRAD, INRAE, AgroParisTech, Université des Antilles, Université de Guyane, 97310 Kourou, France
| | - Clément Stahl
- UMR EcoFoG, CNRS, CIRAD, INRAE, AgroParisTech, Université des Antilles, Université de Guyane, 97310 Kourou, France
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Sobral M. All Traits Are Functional: An Evolutionary Viewpoint. TRENDS IN PLANT SCIENCE 2021; 26:674-676. [PMID: 33994092 DOI: 10.1016/j.tplants.2021.04.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/16/2021] [Accepted: 04/19/2021] [Indexed: 06/12/2023]
Abstract
There is increasing confusion regarding the term 'functional trait' and its links with ecosystem functioning. Functional traits are defined as traits that affect individual fitness. I use an evolutionary rationale that considers the integration of the phenotype, the environmental variation, and the relationship between both, to propose that all traits are functional.
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Affiliation(s)
- Mar Sobral
- Departamento de Bioloxía Funcional, Area de Ecoloxía, Universidade de Santiago de Compostela, Santiago de Compostela, Spain.
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Tebbett SB, Morais RA, Goatley CHR, Bellwood DR. Collapsing ecosystem functions on an inshore coral reef. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 289:112471. [PMID: 33812145 DOI: 10.1016/j.jenvman.2021.112471] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 02/23/2021] [Accepted: 03/21/2021] [Indexed: 06/12/2023]
Abstract
Ecosystem functions underpin productivity and key services to humans, such as food provision. However, as the severity of environmental stressors intensifies, it is becoming increasingly unclear if, and to what extent, critical functions and services can be sustained. This issue is epitomised on coral reefs, an ecosystem at the forefront of environmental transitions. We provide a functional profile of a coral reef ecosystem, linking time-series data to quantified processes. The data reveal a prolonged collapse of ecosystem functions in this previously resilient system. The results suggest that sediment accumulation in algal turfs has led to a decline in resource yields to herbivorous fishes and a decrease in fish-based ecosystem functions, including a collapse of both fish biomass and productivity. Unfortunately, at present, algal turf sediment accumulation is rarely monitored nor managed in coral reef systems. Our examination of functions through time highlights the value of directly assessing functions, their potential vulnerability, and the capacity of algal turf sediments to overwhelm productive high-diversity coral reef ecosystems.
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Affiliation(s)
- Sterling B Tebbett
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering and ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, 4811, Australia.
| | - Renato A Morais
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering and ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, 4811, Australia
| | - Christopher H R Goatley
- Function, Evolution and Anatomy Research Lab and Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, New South Wales, 2351, Australia; Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney, New South Wales, 2010, Australia
| | - David R Bellwood
- Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering and ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, 4811, Australia
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Kearney MR, Jusup M, McGeoch MA, Kooijman SALM, Chown SL. Where do functional traits come from? The role of theory and models. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13829] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Michael R. Kearney
- School of BioSciences Faculty of Science The University of Melbourne Melbourne Vic. Australia
| | - Marko Jusup
- Tokyo Tech World Hub Research Initiative Institute of Innovative Research Tokyo Institute of Technology Tokyo Japan
| | - Melodie A. McGeoch
- Department of Ecology Environment and Evolution School of Life Sciences La Trobe University Melbourne Vic. Australia
| | | | - Steven L. Chown
- Securing Antarctica's Environmental Future School of Biological Sciences Monash University Melbourne Vic. Australia
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16
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Modolo GS, dos Santos VAHF, Ferreira MJ. Testing for functional significance of traits: Effect of the light environment in tropical tree saplings. Ecol Evol 2021; 11:6480-6492. [PMID: 34141233 PMCID: PMC8207416 DOI: 10.1002/ece3.7499] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 03/11/2021] [Accepted: 03/12/2021] [Indexed: 01/15/2023] Open
Abstract
Functional traits have been examined to explain the growth rates of forest communities in different sites. However, weak or nonexistent relations are often found, especially due to the following methodological aspects: 1) lack of an environmental context (e.g., light, water, or nutrient supply), 2) use of nonfunctional traits, 3) an approach that does not contemplate phenotypic integration, and 4) neglect of intraspecific variation.Here we measured relative growth rates, crown, and leaf traits in saplings of six tropical tree species growing in two light environments (Gap and Understory) to test whether contrasting light environments modulates trait-trait and trait-growth relationships. Moreover, we tested whether models that integrate traits of different dimensions of the plant (crown and leaf) improve the strength of trait-growth relations.Light availability changed both trait-trait and trait-growth relationships. Overall, in Understory, crown traits (crown length and total leaf area) have a stronger effect on growth rates, while physiological traits related to nutrient acquisition (nitrogen concentration), photochemical efficiency (chlorophyll pigments and chlorophyll a fluorescence), and biochemical efficiency (potassium use efficiency) are strong in Gap. Models including multiple traits explained growth rates better in Gap (up to 62%) and Understory (up to 47%), but just in Gap the best model comprises traits that are representative of different dimensions of the plant. Synthesis. We advanced the knowledge behind the light effects on tree sapling by posit that trait-trait and trait-growth relationships vary across light environments. Therefore, light availability is a key environmental factor to be considered when choosing the set of traits to be measured in functional approach studies using tropical tree saplings. In compliance with the phenotype integration hypothesis, functional traits are better predictors of growth rates when grouped in a set of traits of different dimensions of the plant that represent different functional mechanisms.
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