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Lin Y, Xie T, Li S, Li X, Liu W. Amplified photosynthetic responses to drought events offset the positive effects of warming on arid desert plants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 952:175899. [PMID: 39222813 DOI: 10.1016/j.scitotenv.2024.175899] [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: 06/09/2024] [Revised: 08/26/2024] [Accepted: 08/28/2024] [Indexed: 09/04/2024]
Abstract
Ongoing warming will influence plant photosynthesis via thermal effects and by enhancing water deficit. As the primary limiting factor for the growth and development of plants in arid deserts, water may alter the potential warming effects on plant photosynthesis and lead to increased uncertainty in plant dynamics. Here, we used open-top chambers (OTCs) to evaluate the impacts of in situ warming (+0.5 and +1.5 °C) on the photosynthesis and growth of two representative desert plants, Artemisia ordosica and Grubovia dasyphylla, from wet to dry spells. The plant traits associated with photosynthetic diffusive and biochemical processes were also measured to explore the underlying mechanisms involved. We found that warming significantly increased the net photosynthetic rate (Anet) during wet spells under 1.5 °C warming in both plants, while only increased that of A. ordosica under 0.5 °C warming. During dry spells, Anet decreased both in A. ordosica and G. dasyphylla, with the rates of declining being 48 % and 41 %, respectively, higher than control under warming. Consequently, warming significantly amplified photosynthetic responses to drought events, which offset the positive warming effects during wet spells and led to unchanged plant biomass in both species. Besides, alterations in plant traits tended to be associated with positive warming effects during wet spells, and the negative effects of drought were mainly due to stomatal limitation. Our results emphasised that the potential benefits of warming during wet spells may be reversed during drought events. Thus, the adverse effects of ongoing warming on desert productivity may increase during dry spells in growing seasons and during dry years.
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Affiliation(s)
- Yuwei Lin
- Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-environment and Resource Research, Chinese Academy of Sciences, Lanzhou, China; University of Chinese Academy of Sciences, Beijing, China
| | - Ting Xie
- Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-environment and Resource Research, Chinese Academy of Sciences, Lanzhou, China; University of Chinese Academy of Sciences, Beijing, China
| | - Shuanglang Li
- Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-environment and Resource Research, Chinese Academy of Sciences, Lanzhou, China; University of Chinese Academy of Sciences, Beijing, China
| | - Xinrong Li
- Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-environment and Resource Research, Chinese Academy of Sciences, Lanzhou, China; University of Chinese Academy of Sciences, Beijing, China.
| | - Wenjing Liu
- Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-environment and Resource Research, Chinese Academy of Sciences, Lanzhou, China; University of Chinese Academy of Sciences, Beijing, China
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2
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Manzi OJL, Wittemann M, Dusenge ME, Habimana J, Manishimwe A, Mujawamariya M, Ntirugulirwa B, Zibera E, Tarvainen L, Nsabimana D, Wallin G, Uddling J. Canopy temperatures strongly overestimate leaf thermal safety margins of tropical trees. THE NEW PHYTOLOGIST 2024; 243:2115-2129. [PMID: 39073111 DOI: 10.1111/nph.20013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 07/07/2024] [Indexed: 07/30/2024]
Abstract
Current estimates of temperature effects on plants mostly rely on air temperature, although it can significantly deviate from leaf temperature (Tleaf). To address this, some studies have used canopy temperature (Tcan). However, Tcan fails to capture the fine-scale variation in Tleaf among leaves and species in diverse canopies. We used infrared radiometers to study Tleaf and Tcan and how they deviate from air temperature (ΔTleaf and ΔTcan) in multispecies tropical tree plantations at three sites along an elevation and temperature gradient in Rwanda. Our results showed high Tleaf (up to c. 50°C) and ΔTleaf (on average 8-10°C and up to c. 20°C) of sun-exposed leaves during 10:00 h-15:00 h, being close to or exceeding photosynthetic heat tolerance thresholds. These values greatly exceeded simultaneously measured values of Tcan and ΔTcan, respectively, leading to strongly overestimated leaf thermal safety margins if basing those on Tcan data. Stomatal conductance and leaf size affected Tleaf and Tcan in line with their expected influences on leaf energy balance. Our findings highlight the importance of leaf traits for leaf thermoregulation and show that monitoring Tcan is not enough to capture the peak temperatures and heat stress experienced by individual leaves of different species in tropical forest canopies.
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Affiliation(s)
- Olivier Jean Leonce Manzi
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 463, Gothenburg, SE-405 30, Sweden
- Integrated Polytechnic Regional College-Kitabi, Rwanda Polytechnic, PO Box 330, Huye, Rwanda
| | - Maria Wittemann
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 463, Gothenburg, SE-405 30, Sweden
| | - Mirindi Eric Dusenge
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 463, Gothenburg, SE-405 30, Sweden
- Department of Biology, Mount Allison University, Sackville, NB, E4L 1E4, Canada
| | - Jacques Habimana
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 463, Gothenburg, SE-405 30, Sweden
| | - Aloysie Manishimwe
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 463, Gothenburg, SE-405 30, Sweden
- Department of Biology, College of Science and Technology, University of Rwanda, Avenue de l'Armée, PO Box 3900, Kigali, Rwanda
| | - Myriam Mujawamariya
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 463, Gothenburg, SE-405 30, Sweden
- Department of Biology, College of Science and Technology, University of Rwanda, Avenue de l'Armée, PO Box 3900, Kigali, Rwanda
| | - Bonaventure Ntirugulirwa
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 463, Gothenburg, SE-405 30, Sweden
- Department of Biology, College of Science and Technology, University of Rwanda, Avenue de l'Armée, PO Box 3900, Kigali, Rwanda
- Rwanda Agriculture and Animal Resources Development Board, PO Box 5016, Kigali, Rwanda
- Rwanda Forestry Authority, PO Box 46, Muhanga, Rwanda
| | - Etienne Zibera
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 463, Gothenburg, SE-405 30, Sweden
- School of Agriculture and Food Sciences, College of Agriculture, Animal Sciences and Veterinary Medicine, University of Rwanda, PO Box 210, Musanze, Rwanda
| | - Lasse Tarvainen
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 463, Gothenburg, SE-405 30, Sweden
| | - Donat Nsabimana
- School of Forestry and Biodiversity Conservation, College of Agriculture, Animal Sciences and Veterinary Medicine, University of Rwanda, PO Box 210, Musanze, Rwanda
| | - Göran Wallin
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 463, Gothenburg, SE-405 30, Sweden
| | - Johan Uddling
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 463, Gothenburg, SE-405 30, Sweden
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3
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Dusenge ME, Warren JM, Reich PB, Ward EJ, Murphy BK, Stefanski A, Bermudez R, Cruz M, McLennan DA, King AW, Montgomery RA, Hanson PJ, Way DA. Photosynthetic capacity in middle-aged larch and spruce acclimates independently to experimental warming and elevated CO 2. PLANT, CELL & ENVIRONMENT 2024. [PMID: 39101396 DOI: 10.1111/pce.15068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Accepted: 07/18/2024] [Indexed: 08/06/2024]
Abstract
Photosynthetic acclimation to both warming and elevated CO2 of boreal trees remains a key uncertainty in modelling the response of photosynthesis to future climates. We investigated the impact of increased growth temperature and elevated CO2 on photosynthetic capacity (Vcmax and Jmax) in mature trees of two North American boreal conifers, tamarack and black spruce. We show that Vcmax and Jmax at a standard temperature of 25°C did not change with warming, while Vcmax and Jmax at their thermal optima (Topt) and growth temperature (Tg) increased. Moreover, Vcmax and Jmax at either 25°C, Topt or Tg decreased with elevated CO2. The Jmax/Vcmax ratio decreased with warming when assessed at both Topt and Tg but did not significantly vary at 25°C. The Jmax/Vcmax increased with elevated CO2 at either reference temperature. We found no significant interaction between warming and elevated CO2 on all traits. If this lack of interaction between warming and elevated CO2 on the Vcmax, Jmax and Jmax/Vcmax ratio is a general trend, it would have significant implications for improving photosynthesis representation in vegetation models. However, future research is required to investigate the widespread nature of this response in a larger number of species and biomes.
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Affiliation(s)
- Mirindi Eric Dusenge
- Department of Biology, Mount Allison University, Sackville, New Brunswick, Canada
- Department of Biology, The University of Western Ontario, London, Ontario, Canada
| | - Jeffrey M Warren
- Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Peter B Reich
- Institute for Global Change Biology, and School for the Environment and Sustainability, University of Michigan, Ann Arbor, Michigan, USA
- Department of Forest Resources, University of Minnesota, Saint Paul, Minnesota, USA
- Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, New South Wales, Australia
| | - Eric J Ward
- Earth System Science Interdisciplinary Center, University of Maryland, College Park, Maryland, USA
| | - Bridget K Murphy
- Department of Biology, The University of Western Ontario, London, Ontario, Canada
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
- Graduate Program in Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Artur Stefanski
- Department of Forest Resources, University of Minnesota, Saint Paul, Minnesota, USA
| | - Raimundo Bermudez
- Department of Forest Resources, University of Minnesota, Saint Paul, Minnesota, USA
| | - Marisol Cruz
- Departamento de Ciencias Biologicas, Universidad de Los Andes, Bogota, Colombia
| | - David A McLennan
- Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Anthony W King
- Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Rebecca A Montgomery
- Department of Forest Resources, University of Minnesota, Saint Paul, Minnesota, USA
| | - Paul J Hanson
- Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Danielle A Way
- Department of Biology, The University of Western Ontario, London, Ontario, Canada
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, Australia
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, New York, USA
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4
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Rodríguez-Ramírez EC, Frei J, Ames-Martínez FN, Guerra A, Andrés-Hernández AR. Ecological stress memory in wood architecture of two Neotropical hickory species from central-eastern Mexico. BMC PLANT BIOLOGY 2024; 24:638. [PMID: 38971728 PMCID: PMC11227188 DOI: 10.1186/s12870-024-05348-2] [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: 04/24/2024] [Accepted: 06/27/2024] [Indexed: 07/08/2024]
Abstract
BACKGROUND Drought periods are major evolutionary triggers of wood anatomical adaptive variation in Lower Tropical Montane Cloud Forests tree species. We tested the influence of historical drought events on the effects of ecological stress memory on latewood width and xylem vessel traits in two relict hickory species (Carya palmeri and Carya myristiciformis) from central-eastern Mexico. We hypothesized that latewood width would decrease during historical drought years, establishing correlations between growth and water stress conditions, and that moisture deficit during past tree growth between successive drought events, would impact on wood anatomical features. We analyzed latewood anatomical traits that developed during historical drought and pre- and post-drought years in both species. RESULTS We found that repeated periods of hydric stress left climatic signatures for annual latewood growth and xylem vessel traits that are essential for hydric adaptation in tropical montane hickory species. CONCLUSIONS Our results demonstrate the existence of cause‒effect relationships in wood anatomical architecture and highlight the ecological stress memory linked with historical drought events. Thus, combined time-series analysis of latewood width and xylem vessel traits is a powerful tool for understanding the ecological behavior of hickory species.
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Affiliation(s)
- Ernesto C Rodríguez-Ramírez
- Laboratorio de Dendrocronología, Universidad Continental, Urbanización San Antonio, Avenida San Carlos 1980, Huancayo, Junín, Peru.
| | - Jonas Frei
- Atelier foifacht, Juglandaceae expert, Schaffhausen, Switzerland
| | - Fressia N Ames-Martínez
- Laboratorio de Biotecnología y Biología Molecular, Universidad Continental, Urbanización San Antonio, Huancayo, Peru
- Programa de Investigación de Ecología y Biodiversidad, Asociación ANDINUS, Calle Miguel Grau 370, Sicaya, Junín, Huancayo, Peru
| | - Anthony Guerra
- Programa de Pós-Graduação em Agronomia/Fisiologia Vegetal, Departamento de Biologia- Instituto de Ciências Naturais, Universidade Federal de Lavras, Lavras, Minas Gerais, 7203-202, Brazil
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5
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Wang Z, Wang X, Han B, Liu D, Wang C. Balance between carbon gain and loss in warmer environments: impacts on photosynthesis and leaf respiration in four temperate tree species. TREE PHYSIOLOGY 2024; 44:tpae070. [PMID: 38905287 DOI: 10.1093/treephys/tpae070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 05/31/2024] [Accepted: 06/20/2024] [Indexed: 06/23/2024]
Abstract
The temperature sensitivities of photosynthesis and respiration remain a key uncertainty in predicting how forests will respond to climate warming. We grew seedlings of four temperate tree species, including Betula platyphylla, Fraxinus mandshurica, Juglans mandshurica and Tilia amurensis, at three temperature regimes (ambient, +2 °C, and +4 °C in daytime air temperature). We investigated net photosynthesis (Anet25), maximum rate of RuBP-carboxylation (Vcmax25) and RuBP-regeneration (Jmax25), stomatal conductance (gs25), mesophyll conductance (gm25), and leaf respiration (Rleaf) in dark (Rdark25) and in light (Rlight25) at 25 °C in all species. Additionally, we examined the temperature sensitivities of Anet, Vcmax, Jmax, Rdark and Rlight in F. mandshurica. Our findings showed that the warming-induced decreases in Anet25, Vcmax25 and Jmax25 were more prevalent in the late-successional species T. amurensis. Warming had negative impacts on gs25 in all species. Overall, Anet25 was positively correlated with Vcmax25 and Jmax25 across all growth temperatures. However, a positive correlation between Anet25 and gs25 was observed only under warming conditions, and gs25 was negatively associated with vapor pressure deficit. This implies that the vapor pressure deficit-induced decrease in gs25 was responsible for the decline in Anet25 at higher temperatures. The optimum temperature of Anet in F. mandshurica increased by 0.59 °C per 1.0 °C rise in growth temperature. While +2 °C elevated the thermal optima of Jmax, it did not affect the other temperature sensitivity parameters of Vcmax and Jmax. Rdark25 was not affected by warming in any species, and Rlight25 was stimulated in T. amurensis. The temperature response curves of Rdark and Rlight in F. mandshurica were not altered by warming, implying a lack of thermal acclimation. The ratios of Rdark25 and Rlight25 to Anet25 and Vcmax25 in T. amurensis increased with warming. These results suggest that Anet and Rleaf did not acclimate to warming synchronously in these temperate tree species.
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Affiliation(s)
- Zhaoguo Wang
- School of Ecology, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China
| | - Xiaochun Wang
- School of Ecology, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China
| | - Bingxin Han
- School of Ecology, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China
| | - Di Liu
- School of Ecology, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China
| | - Chuankuan Wang
- School of Ecology, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China
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6
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Drake JE, Vårhammar A, Aspinwall MJ, Pfautsch S, Ghannoum O, Tissue DT, Tjoelker MG. Pushing the envelope: do narrowly and widely distributed Eucalyptus species differ in response to climate warming? THE NEW PHYTOLOGIST 2024; 243:82-97. [PMID: 38666344 DOI: 10.1111/nph.19774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 03/29/2024] [Indexed: 06/07/2024]
Abstract
Contemporary climate change will push many tree species into conditions that are outside their current climate envelopes. Using the Eucalyptus genus as a model, we addressed whether species with narrower geographical distributions show constrained ability to cope with warming relative to species with wider distributions, and whether this ability differs among species from tropical and temperate climates. We grew seedlings of widely and narrowly distributed Eucalyptus species from temperate and tropical Australia in a glasshouse under two temperature regimes: the summer temperature at seed origin and +3.5°C. We measured physical traits and leaf-level gas exchange to assess warming influences on growth rates, allocation patterns, and physiological acclimation capacity. Warming generally stimulated growth, such that higher relative growth rates early in development placed seedlings on a trajectory of greater mass accumulation. The growth enhancement under warming was larger among widely than narrowly distributed species and among temperate rather than tropical provenances. The differential growth enhancement was primarily attributable to leaf area production and adjustments of specific leaf area. Our results suggest that tree species, including those with climate envelopes that will be exceeded by contemporary climate warming, possess capacity to physiologically acclimate but may have varying ability to adjust morphology.
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Affiliation(s)
- John E Drake
- Department of Sustainable Resources Management, College of Environmental Science and Forestry, State University of New York, 1 Forestry Drive, Syracuse, NY, 13210, USA
| | - Angelica Vårhammar
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | | | - Sebastian Pfautsch
- Urban Transformations Research Centre, Western Sydney University, Locked Bag 1797, Penrith, 2751, NSW, Australia
| | - Oula Ghannoum
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Mark G Tjoelker
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
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7
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Denney DA, Patel P, Anderson JT. Elevated [CO 2] and temperature augment gas exchange and shift the fitness landscape in a montane forb. THE NEW PHYTOLOGIST 2024; 243:58-71. [PMID: 38655662 DOI: 10.1111/nph.19765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 03/29/2024] [Indexed: 04/26/2024]
Abstract
Climate change is simultaneously increasing carbon dioxide concentrations ([CO2]) and temperature. These factors could interact to influence plant physiology and performance. Alternatively, increased [CO2] may offset costs associated with elevated temperatures. Furthermore, the interaction between elevated temperature and [CO2] may differentially affect populations from along an elevational gradient and disrupt local adaptation. We conducted a multifactorial growth chamber experiment to examine the interactive effects of temperature and [CO2] on fitness and ecophysiology of diverse accessions of Boechera stricta (Brassicaceae) sourced from a broad elevational gradient in Colorado. We tested whether increased [CO2] would enhance photosynthesis across accessions, and whether warmer conditions would depress the fitness of high-elevation accessions owing to steep reductions in temperature with increasing elevation in this system. Elevational clines in [CO2] are not as evident, making it challenging to predict how locally adapted ecotypes will respond to elevated [CO2]. This experiment revealed that elevated [CO2] increased photosynthesis and intrinsic water use efficiency across all accessions. However, these instantaneous responses to treatments did not translate to changes in fitness. Instead, increased temperatures reduced the probability of reproduction for all accessions. Elevated [CO2] and increased temperatures interacted to shift the adaptive landscape, favoring lower elevation accessions for the probability of survival and fecundity. Our results suggest that elevated temperatures and [CO2] associated with climate change could have severe negative consequences, especially for high-elevation populations.
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Affiliation(s)
- Derek A Denney
- Department of Plant Biology, University of Georgia, Athens, GA, 30602, USA
| | - Pratik Patel
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA
| | - Jill T Anderson
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA
- Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA
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8
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Slot M, Rifai SW, Eze CE, Winter K. The stomatal response to vapor pressure deficit drives the apparent temperature response of photosynthesis in tropical forests. THE NEW PHYTOLOGIST 2024. [PMID: 38736030 DOI: 10.1111/nph.19806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 04/18/2024] [Indexed: 05/14/2024]
Abstract
As temperature rises, net carbon uptake in tropical forests decreases, but the underlying mechanisms are not well understood. High temperatures can limit photosynthesis directly, for example by reducing biochemical capacity, or indirectly through rising vapor pressure deficit (VPD) causing stomatal closure. To explore the independent effects of temperature and VPD on photosynthesis we analyzed photosynthesis data from the upper canopies of two tropical forests in Panama with Generalized Additive Models. Stomatal conductance and photosynthesis consistently decreased with increasing VPD, and statistically accounting for VPD increased the optimum temperature of photosynthesis (Topt) of trees from a VPD-confounded apparent Topt of c. 30-31°C to a VPD-independent Topt of c. 33-36°C, while for lianas no VPD-independent Topt was reached within the measured temperature range. Trees and lianas exhibited similar temperature and VPD responses in both forests, despite 1500 mm difference in mean annual rainfall. Over ecologically relevant temperature ranges, photosynthesis in tropical forests is largely limited by indirect effects of warming, through changes in VPD, not by direct warming effects of photosynthetic biochemistry. Failing to account for VPD when determining Topt misattributes the underlying causal mechanism and thereby hinders the advancement of mechanistic understanding of global warming effects on tropical forest carbon dynamics.
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Affiliation(s)
- Martijn Slot
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancón, Panama
| | - Sami W Rifai
- School of Biological Sciences, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Chinedu E Eze
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancón, Panama
- Department of Agronomy, Michael Okpara University of Agriculture, Umudike, Abia State, 440109, Nigeria
| | - Klaus Winter
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancón, Panama
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9
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Cox AJF, González-Caro S, Meir P, Hartley IP, Restrepo Z, Villegas JC, Sanchez A, Mercado LM. Variable thermal plasticity of leaf functional traits in Andean tropical montane forests. PLANT, CELL & ENVIRONMENT 2024; 47:731-750. [PMID: 38047584 DOI: 10.1111/pce.14778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 11/08/2023] [Accepted: 11/21/2023] [Indexed: 12/05/2023]
Abstract
Tropical montane forests (TMFs) are biodiversity hotspots and provide vital ecosystem services, but they are disproportionately vulnerable to climate warming. In the Andes, cold-affiliated species from high elevations are being displaced at the hot end of their thermal distributions by warm-affiliated species migrating upwards from lower elevations, leading to compositional shifts. Leaf functional traits are strong indicators of plant performance and at the community level have been shown to vary along elevation gradients, reflecting plant adaptations to different environmental niches. However, the plastic response of such traits to relatively rapid temperature change in Andean TMF species remains unknown. We used three common garden plantations within a thermosequence in the Colombian Andes to investigate the warming and cooling responses of key leaf functional traits in eight cold- and warm-affiliated species with variable thermal niches. Cold-affiliated species shifted their foliar nutrient concentrations when exposed to warming, while all other traits did not significantly change; contrastingly, warm-affiliated species were able to adjust structural, nutrient and water-use efficiency traits from acquisitive to conservative strategies in response to cooling. Our findings suggest that cold-affiliated species will struggle to acclimate functional traits to warming, conferring warm-affiliated species a competitive advantage under climate change.
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Affiliation(s)
- Andrew J F Cox
- Department of Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, UK
| | - Sebastián González-Caro
- Department of Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, UK
| | - Patrick Meir
- School of Geosciences, University of Edinburgh, Edinburgh, UK
- Division of Plant Sciences, Research, The Australian National University, Canberra, Australia
| | - Iain P Hartley
- Department of Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, UK
| | - Zorayda Restrepo
- Grupo de Investigación en Ecología Aplicada, Universidad de Antioquia, Medellín, Colombia
- Grupo de Servicios Ecositémicos y Cambio Climático, Corporación, Medellín, Colombia
| | - Juan C Villegas
- Grupo de Investigación en Ecología Aplicada, Universidad de Antioquia, Medellín, Colombia
| | - Adriana Sanchez
- Programa de Biología, Facultad de Ciencias Naturales, Universidad del Rosario, Bogotá, Colombia
| | - Lina M Mercado
- Department of Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, UK
- UK Centre for Ecology & Hydrology, Crowmarsh-Gifford, Wallingford, UK
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10
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Zhai B, Hu Z, Sun S, Tang Z, Wang G. Characteristics of photosynthetic rates in different vegetation types at high-altitude in mountainous regions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 907:168071. [PMID: 37898202 DOI: 10.1016/j.scitotenv.2023.168071] [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: 07/03/2023] [Revised: 10/20/2023] [Accepted: 10/21/2023] [Indexed: 10/30/2023]
Abstract
Mountains play an important role in the carbon cycle of the terrestrial ecosystem and are one of the most sensitive ecosystems to climate change. However, our current knowledge regarding the physiological responses of alpine plants to environmental changes remains limited due to the severe climatic conditions prevailing in these high-altitude regions. Therefore, this study quantified the variations in photosynthetic rates (An) and identified their driving factors of herbaceous plants, shrubs, and trees along an elevation gradient (2200 m asl to 3200 m asl) on Mount Gongga. Elevation emerged as a significant determinant of An, with a general increase observed, albeit followed by a decline above 3000 m asl. In high-altitude regions, trees displayed more significant fluctuations in An compared to herbaceous plants and shrubs. The lower levels of atmospheric carbon dioxide concentration (eCO2) and temperature in high-altitude regions resulted in a 16 % increase in An for herbaceous plants, 60 % increase for shrubs, and 43 % increase for trees compared to the low-altitude areas. Structural equation modeling (SEM) analyses underscored the considerable impact of environmental factors on An. Notably, photosynthetically active radiation, eCO2, and stomatal conductance were identified as positive influencers, while other factors exerted negative effects. Our results further highlighted that trees were subject to greater constraints from multiple factors compared to herbs and shrubs, aligning with the outcomes of our variance analysis. In summary, our study presents a comprehensive assessment of vegetation responses to environmental factors along elevational gradients. The significance of An in plants at high altitude to external factors suggests the potential adaptability of alpine plants, and also indicates that changes in photosynthetic physiological functions at high altitude should be paid more attention to in the study of climate change.
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Affiliation(s)
- Biying Zhai
- State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource and Hydropower, Sichuan University, Chengdu 610044, China
| | - Zhaoyong Hu
- State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource and Hydropower, Sichuan University, Chengdu 610044, China.
| | - Shouqin Sun
- State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource and Hydropower, Sichuan University, Chengdu 610044, China.
| | - Zishu Tang
- State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource and Hydropower, Sichuan University, Chengdu 610044, China
| | - Genxu Wang
- State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource and Hydropower, Sichuan University, Chengdu 610044, China
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11
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Jensen AM. Pushing the thermal limit for cacao-will we have chocolate also in a warmer future? TREE PHYSIOLOGY 2023; 43:2047-2049. [PMID: 37694840 DOI: 10.1093/treephys/tpad112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 09/05/2023] [Indexed: 09/12/2023]
Affiliation(s)
- Anna Monrad Jensen
- Department of Forestry and Wood Technology, Linnaeus University, Lückligs 1351 95 Växjö, Sweden
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12
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Feeley KJ, Bernal-Escobar M, Fortier R, Kullberg AT. Tropical Trees Will Need to Acclimate to Rising Temperatures-But Can They? PLANTS (BASEL, SWITZERLAND) 2023; 12:3142. [PMID: 37687387 PMCID: PMC10490527 DOI: 10.3390/plants12173142] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 08/29/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023]
Abstract
For tropical forests to survive anthropogenic global warming, trees will need to avoid rising temperatures through range shifts and "species migrations" or tolerate the newly emerging conditions through adaptation and/or acclimation. In this literature review, we synthesize the available knowledge to show that although many tropical tree species are shifting their distributions to higher, cooler elevations, the rates of these migrations are too slow to offset ongoing changes in temperatures, especially in lowland tropical rainforests where thermal gradients are shallow or nonexistent. We also show that the rapidity and severity of global warming make it unlikely that tropical tree species can adapt (with some possible exceptions). We argue that the best hope for tropical tree species to avoid becoming "committed to extinction" is individual-level acclimation. Although several new methods are being used to test for acclimation, we unfortunately still do not know if tropical tree species can acclimate, how acclimation abilities vary between species, or what factors may prevent or facilitate acclimation. Until all of these questions are answered, our ability to predict the fate of tropical species and tropical forests-and the many services that they provide to humanity-remains critically impaired.
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Affiliation(s)
- Kenneth J. Feeley
- Department of Biology, University of Miami, Coral Gables, FL 33146, USA; (M.B.-E.); (R.F.); (A.T.K.)
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13
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Crous KY, Cheesman AW, Middleby K, Rogers EIE, Wujeska-Klause A, Bouet AYM, Ellsworth DS, Liddell MJ, Cernusak LA, Barton CVM. Similar patterns of leaf temperatures and thermal acclimation to warming in temperate and tropical tree canopies. TREE PHYSIOLOGY 2023; 43:1383-1399. [PMID: 37099805 PMCID: PMC10423462 DOI: 10.1093/treephys/tpad054] [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: 12/14/2022] [Revised: 03/22/2023] [Accepted: 04/17/2023] [Indexed: 06/19/2023]
Abstract
As the global climate warms, a key question is how increased leaf temperatures will affect tree physiology and the coupling between leaf and air temperatures in forests. To explore the impact of increasing temperatures on plant performance in open air, we warmed leaves in the canopy of two mature evergreen forests, a temperate Eucalyptus woodland and a tropical rainforest. The leaf heaters consistently maintained leaves at a target of 4 °C above ambient leaf temperatures. Ambient leaf temperatures (Tleaf) were mostly coupled to air temperatures (Tair), but at times, leaves could be 8-10 °C warmer than ambient air temperatures, especially in full sun. At both sites, Tleaf was warmer at higher air temperatures (Tair > 25 °C), but was cooler at lower Tair, contrary to the 'leaf homeothermy hypothesis'. Warmed leaves showed significantly lower stomatal conductance (-0.05 mol m-2 s-1 or -43% across species) and net photosynthesis (-3.91 μmol m-2 s-1 or -39%), with similar rates in leaf respiration rates at a common temperature (no acclimation). Increased canopy leaf temperatures due to future warming could reduce carbon assimilation via reduced photosynthesis in these forests, potentially weakening the land carbon sink in tropical and temperate forests.
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Affiliation(s)
- K Y Crous
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales 2751, Australia
| | - A W Cheesman
- Centre for Tropical Environmental and Sustainability Science (TESS) and College of Science and Engineering, James Cook University, Cairns, Queensland 4878, Australia
| | - K Middleby
- Centre for Tropical Environmental and Sustainability Science (TESS) and College of Science and Engineering, James Cook University, Cairns, Queensland 4878, Australia
| | - E I E Rogers
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales 2751, Australia
| | - A Wujeska-Klause
- Urban Studies, School of Social Science, Western Sydney University, Penrith, New South Wales 2751, Australia
| | - A Y M Bouet
- Centre for Tropical Environmental and Sustainability Science (TESS) and College of Science and Engineering, James Cook University, Cairns, Queensland 4878, Australia
| | - D S Ellsworth
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales 2751, Australia
| | - M J Liddell
- Centre for Tropical Environmental and Sustainability Science (TESS) and College of Science and Engineering, James Cook University, Cairns, Queensland 4878, Australia
| | - L A Cernusak
- Centre for Tropical Environmental and Sustainability Science (TESS) and College of Science and Engineering, James Cook University, Cairns, Queensland 4878, Australia
| | - C V M Barton
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales 2751, Australia
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14
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Dusenge ME, Warren JM, Reich PB, Ward EJ, Murphy BK, Stefanski A, Bermudez R, Cruz M, McLennan DA, King AW, Montgomery RA, Hanson PJ, Way DA. Boreal conifers maintain carbon uptake with warming despite failure to track optimal temperatures. Nat Commun 2023; 14:4667. [PMID: 37537190 PMCID: PMC10400668 DOI: 10.1038/s41467-023-40248-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 07/13/2023] [Indexed: 08/05/2023] Open
Abstract
Warming shifts the thermal optimum of net photosynthesis (ToptA) to higher temperatures. However, our knowledge of this shift is mainly derived from seedlings grown in greenhouses under ambient atmospheric carbon dioxide (CO2) conditions. It is unclear whether shifts in ToptA of field-grown trees will keep pace with the temperatures predicted for the 21st century under elevated atmospheric CO2 concentrations. Here, using a whole-ecosystem warming controlled experiment under either ambient or elevated CO2 levels, we show that ToptA of mature boreal conifers increased with warming. However, shifts in ToptA did not keep pace with warming as ToptA only increased by 0.26-0.35 °C per 1 °C of warming. Net photosynthetic rates estimated at the mean growth temperature increased with warming in elevated CO2 spruce, while remaining constant in ambient CO2 spruce and in both ambient CO2 and elevated CO2 tamarack with warming. Although shifts in ToptA of these two species are insufficient to keep pace with warming, these boreal conifers can thermally acclimate photosynthesis to maintain carbon uptake in future air temperatures.
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Affiliation(s)
- Mirindi Eric Dusenge
- Department of Biology, Mount Allison University, Sackville, NB, E4L 1E4, Canada.
- Western Centre for Climate Change, Sustainable Livelihoods and Health, Department of Geography and Environment, The University of Western Ontario, London, ON, N6G 2V4, Canada.
- Department of Biology, The University of Western Ontario, London, ON, N6A 3K7, Canada.
| | - Jeffrey M Warren
- Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, Saint Paul, MN, 55108, USA
- Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, NSW, 2753, Australia
- Institute for Global Change Biology, and School for the Environment and Sustainability, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Eric J Ward
- US Geological Survey, Wetland and Aquatic Research Center, Lafayette, LA, USA
| | - Bridget K Murphy
- Department of Biology, The University of Western Ontario, London, ON, N6A 3K7, Canada
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada
- Graduate Program in Cell and Systems Biology, University of Toronto, Toronto, ON, M5S 3B2, Canada
| | - Artur Stefanski
- Department of Forest Resources, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Raimundo Bermudez
- Department of Forest Resources, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Marisol Cruz
- Departamento de Ciencias Biologicas, Universidad de Los Andes, Bogota, Colombia
| | - David A McLennan
- Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Anthony W King
- Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Rebecca A Montgomery
- Department of Forest Resources, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Paul J Hanson
- Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Danielle A Way
- Department of Biology, The University of Western Ontario, London, ON, N6A 3K7, Canada.
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia.
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA.
- Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, 11973, USA.
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15
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Mata-Guel EO, Soh MCK, Butler CW, Morris RJ, Razgour O, Peh KSH. Impacts of anthropogenic climate change on tropical montane forests: an appraisal of the evidence. Biol Rev Camb Philos Soc 2023; 98:1200-1224. [PMID: 36990691 DOI: 10.1111/brv.12950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 03/08/2023] [Accepted: 03/10/2023] [Indexed: 03/31/2023]
Abstract
In spite of their small global area and restricted distributions, tropical montane forests (TMFs) are biodiversity hotspots and important ecosystem services providers, but are also highly vulnerable to climate change. To protect and preserve these ecosystems better, it is crucial to inform the design and implementation of conservation policies with the best available scientific evidence, and to identify knowledge gaps and future research needs. We conducted a systematic review and an appraisal of evidence quality to assess the impacts of climate change on TMFs. We identified several skews and shortcomings. Experimental study designs with controls and long-term (≥10 years) data sets provide the most reliable evidence, but were rare and gave an incomplete understanding of climate change impacts on TMFs. Most studies were based on predictive modelling approaches, short-term (<10 years) and cross-sectional study designs. Although these methods provide moderate to circumstantial evidence, they can advance our understanding on climate change effects. Current evidence suggests that increasing temperatures and rising cloud levels have caused distributional shifts (mainly upslope) of montane biota, leading to alterations in biodiversity and ecological functions. Neotropical TMFs were the best studied, thus the knowledge derived there can serve as a proxy for climate change responses in under-studied regions elsewhere. Most studies focused on vascular plants, birds, amphibians and insects, with other taxonomic groups poorly represented. Most ecological studies were conducted at species or community levels, with a marked paucity of genetic studies, limiting understanding of the adaptive capacity of TMF biota. We thus highlight the long-term need to widen the methodological, thematic and geographical scope of studies on TMFs under climate change to address these uncertainties. In the short term, however, in-depth research in well-studied regions and advances in computer modelling approaches offer the most reliable sources of information for expeditious conservation action for these threatened forests.
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Affiliation(s)
- Erik O Mata-Guel
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Malcolm C K Soh
- National Park Boards, 1 Cluny Road, Singapore, 259569, Singapore
| | - Connor W Butler
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Rebecca J Morris
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Orly Razgour
- Biosciences, University of Exeter, Exeter, EX4 4PS, UK
| | - Kelvin S-H Peh
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
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16
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Cox AJF, Hartley IP, Meir P, Sitch S, Dusenge ME, Restrepo Z, González-Caro S, Villegas JC, Uddling J, Mercado LM. Acclimation of photosynthetic capacity and foliar respiration in Andean tree species to temperature change. THE NEW PHYTOLOGIST 2023; 238:2329-2344. [PMID: 36987979 DOI: 10.1111/nph.18900] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 03/13/2023] [Indexed: 05/19/2023]
Abstract
Climate warming is causing compositional changes in Andean tropical montane forests (TMFs). These shifts are hypothesised to result from differential responses to warming of cold- and warm-affiliated species, with the former experiencing mortality and the latter migrating upslope. The thermal acclimation potential of Andean TMFs remains unknown. Along a 2000 m Andean altitudinal gradient, we planted individuals of cold- and warm-affiliated species (under common soil and irrigation), exposing them to the hot and cold extremes of their thermal niches, respectively. We measured the response of net photosynthesis (Anet ), photosynthetic capacity and leaf dark respiration (Rdark ) to warming/cooling, 5 months after planting. In all species, Anet and photosynthetic capacity at 25°C were highest when growing at growth temperatures (Tg ) closest to their thermal means, declining with warming and cooling in cold-affiliated and warm-affiliated species, respectively. When expressed at Tg , photosynthetic capacity and Rdark remained unchanged in cold-affiliated species, but the latter decreased in warm-affiliated counterparts. Rdark at 25°C increased with temperature in all species, but remained unchanged when expressed at Tg . Both species groups acclimated to temperature, but only warm-affiliated species decreased Rdark to photosynthetic capacity ratio at Tg as temperature increased. This could confer them a competitive advantage under future warming.
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Affiliation(s)
- Andrew J F Cox
- Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4RKJ, UK
| | - Iain P Hartley
- Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4RKJ, UK
| | - Patrick Meir
- School of Geosciences, University of Edinburgh, Edinburgh, EH9 3JN, UK
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Stephen Sitch
- Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4RKJ, UK
| | - Mirindi Eric Dusenge
- Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4RKJ, UK
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, SE-405 30, Sweden
- Department of Biology, The University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Zorayda Restrepo
- Grupo de Investigación en Ecología Aplicada, Universidad de Antioquia, Medellín, Colombia
- UK Centre for Ecology and Hydrology, Crowmarsh-Gifford, Wallingford, OX10 8BB, UK
| | - Sebastian González-Caro
- Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4RKJ, UK
- UK Centre for Ecology and Hydrology, Crowmarsh-Gifford, Wallingford, OX10 8BB, UK
| | - Juan Camilo Villegas
- Grupo de Investigación en Ecología Aplicada, Universidad de Antioquia, Medellín, Colombia
| | - Johan Uddling
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, SE-405 30, Sweden
| | - Lina M Mercado
- Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4RKJ, UK
- UK Centre for Ecology and Hydrology, Crowmarsh-Gifford, Wallingford, OX10 8BB, UK
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17
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Spiers JA, Oatham MP, Rostant LV, Farrell AD. Determining the ecophysiological limits of a narrow niche tropical conifer tree (Podocarpus trinitensis). TREE PHYSIOLOGY 2023; 43:781-793. [PMID: 36585840 DOI: 10.1093/treephys/tpac151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 12/06/2022] [Accepted: 12/23/2022] [Indexed: 05/13/2023]
Abstract
Many tropical species live close to their thermal limits within a narrow niche. Here, we investigate the ecophysiological limits of the tropical tree Podocarpus trinitensis, which is endemic to Trinidad and Tobago where most populations exist as isolated stands on hilltops. Five wild stands from a range of elevations were compared in the field with measurements of leaf temperature, canopy cover, stomatal conductance (gs), chlorophyll content and several chlorophyll fluorescence parameters. A parallel greenhouse experiment was used to acclimate seedlings to 'CONTROL' and 'HEAT' treatments (with mid-day air temperatures of 34.5 and 37 °C respectively), after which the above parameters were measured along with photosynthetic light and temperature response curves, leaf morphology and in vitro Fv/Fm thermostability. There was a positive association between improved physiological performance and elevation. In the high elevation sites, leaf temperatures were significantly lower while most of the physiological parameters were higher (gs, chlorophyll content, ɸ PSII, ETRmax and Isat90). In the greenhouse, HEAT and CONTROL plants were similar for most parameters, except leaf temperature (which was coupled with air temperature) and leaf mass per unit area (which was higher in HEAT plants). Temperature response curves showed an optimum temperature for photosynthesis of 30 ± 0.5 °C (TOpt) and in vitro Fv/Fm indicated a critical temperature of 47.4 ± 0.38 °C for HEAT and 48.2 ± 0.24 °C for CONTROL (T50), with no indication of heat acclimation. Podocarpus trinitensis was found to be shade tolerant. In the field, seedlings established under a close canopy (>95% canopy cover) and had a low light saturation point (LCP). In the greenhouse, where more light was available, seedlings retained a low light compensation point, light saturation point (LSP) and maximum photosynthetic rate (Amax). The results suggest that P. trinitensis is moderately heat tolerant with the higher elevation sites being more habitable, but stands are also able to survive near sea level under a closed canopy. The narrow niche, along with the 30 ± 0.5 °C optimum temperature for photosynthesis and the lack of thermal plasticity in critical temperature, suggests that P. trinitensis has little room to acclimate to temperatures higher than those currently experienced.
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Affiliation(s)
- Joshua A Spiers
- Department of Life Sciences, University of the West Indies, St. Augustine Campus, St. Augustine, Trinidad and Tobago
| | - Michael P Oatham
- Department of Life Sciences, University of the West Indies, St. Augustine Campus, St. Augustine, Trinidad and Tobago
| | - Luke V Rostant
- Department of Life Sciences, University of the West Indies, St. Augustine Campus, St. Augustine, Trinidad and Tobago
| | - Aidan D Farrell
- Department of Life Sciences, University of the West Indies, St. Augustine Campus, St. Augustine, Trinidad and Tobago
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18
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Mujawamariya M, Wittemann M, Dusenge ME, Manishimwe A, Ntirugulirwa B, Zibera E, Nsabimana D, Wallin G, Uddling J. Contrasting warming responses of photosynthesis in early- and late-successional tropical trees. TREE PHYSIOLOGY 2023:tpad035. [PMID: 36971469 DOI: 10.1093/treephys/tpad035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 02/01/2023] [Indexed: 06/18/2023]
Abstract
The productivity and climate feedbacks of tropical forests depend on tree physiological responses to warmer and, over large areas, seasonally drier conditions. However, knowledge regarding such responses is limited due to data scarcity. We studied the impact of growth temperature on net photosynthesis (An), maximum rates of Rubisco carboxylation at 25°C (Vcmax25), stomatal conductance (gs) and the slope parameter of the stomatal conductance-photosynthesis model (g1), in ten early- (ES) and eight late-successional (LS) tropical tree species grown at three sites along an elevation gradient in Rwanda, differing by 6.8°C in daytime ambient air temperature. The effect of seasonal drought on An was also investigated. We found that warm climate decreased wet-season An in LS species, but not in ES species. Values of Vcmax25 were lower at the warmest site across both successional groups, and An and Vcmax25 were higher in ES compared to LS species. Stomatal conductance exhibited no significant site differences and g1 was similar across both sites and successional groups. Drought strongly reduced An at warmer sites but not at the coolest montane site and this response was similar in both ES and LS species. Our results suggest that warming has negative effects on leaf-level photosynthesis in LS species, while both LS and ES species suffer photosynthesis declines in a warmer climate with more pronounced droughts. The contrasting responses of An between successional groups may lead to shifts in species' competitive balance in a warmer world, to the disadvantage of LS trees.
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Affiliation(s)
- Myriam Mujawamariya
- Department of Biology, College of Science and Technology, University of Rwanda, Avenue de l'Armée, Kigali P.O.Box 3900, Rwanda
- Center of Excellence in Biodiversity Conservation and Natural Resources Management, College of Science and Technology, University of Rwanda, Avenue de l'Armée, Kigali P.O.Box 3900, Rwanda
- Department of Biological and Environmental Sciences, University of Gothenburg, P.O. Box 461, SE-405 30 Gothenburg, Sweden
| | - Maria Wittemann
- Department of Biological and Environmental Sciences, University of Gothenburg, P.O. Box 461, SE-405 30 Gothenburg, Sweden
| | - Mirindi Eric Dusenge
- Western Center for Climate Change, Sustainable Livelihoods and Health, Department of Geography, The University of Western Ontario, London, Ontario, Canada
- College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4RJ, United Kingdom
| | - Aloysie Manishimwe
- Department of Biology, College of Science and Technology, University of Rwanda, Avenue de l'Armée, Kigali P.O.Box 3900, Rwanda
- Center of Excellence in Biodiversity Conservation and Natural Resources Management, College of Science and Technology, University of Rwanda, Avenue de l'Armée, Kigali P.O.Box 3900, Rwanda
- Department of Biological and Environmental Sciences, University of Gothenburg, P.O. Box 461, SE-405 30 Gothenburg, Sweden
| | - Bonaventure Ntirugulirwa
- Department of Biology, College of Science and Technology, University of Rwanda, Avenue de l'Armée, Kigali P.O.Box 3900, Rwanda
- Department of Biological and Environmental Sciences, University of Gothenburg, P.O. Box 461, SE-405 30 Gothenburg, Sweden
- Rwanda Forestry Authority, Muhanga P.O. Box 46, Rwanda
| | - Etienne Zibera
- School of Forestry and Biodiversity, College of Agriculture, Animal Sciences and Veterinary Medicine, University of Rwanda, Musanze P.O. Box 210, Rwanda
| | - Donat Nsabimana
- Center of Excellence in Biodiversity Conservation and Natural Resources Management, College of Science and Technology, University of Rwanda, Avenue de l'Armée, Kigali P.O.Box 3900, Rwanda
- School of Forestry and Biodiversity, College of Agriculture, Animal Sciences and Veterinary Medicine, University of Rwanda, Musanze P.O. Box 210, Rwanda
| | - Göran Wallin
- Department of Biological and Environmental Sciences, University of Gothenburg, P.O. Box 461, SE-405 30 Gothenburg, Sweden
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, OX1 3QY, United Kingdom
| | - Johan Uddling
- Department of Biological and Environmental Sciences, University of Gothenburg, P.O. Box 461, SE-405 30 Gothenburg, Sweden
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19
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Wang L, Zheng J, Wang G, Dang QL. Combined effects of elevated CO2 and warmer temperature on limitations to photosynthesis and carbon sequestration in yellow birch. TREE PHYSIOLOGY 2023; 43:379-389. [PMID: 36322135 DOI: 10.1093/treephys/tpac128] [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: 08/04/2022] [Revised: 10/13/2022] [Accepted: 09/30/2022] [Indexed: 05/03/2023]
Abstract
Elevated CO2 and warmer temperature occur simultaneously under the current climate change. However, their combined effects on the photosynthetic traits in boreal trees are not well understood. This study investigated the morphological and photosynthetic responses of yellow birch (Betula alleghaniensis Britt.) to a combined treatment of CO2 and temperature (ambient, ACT (400 μmol mol-1 CO2 and current temperature) vs elevated, ECT (750 μmol mol-1 CO2 and current +4 °C temperature)). It was found that ECT significantly reduced leaf-area based photosynthetic rate (An), maximum Rubisco carboxylation rate (Vcmax), photosynthetic electron transport rate (Jmax), leaf nitrogen concentration, respiration and mesophyll conductance. There were two interesting findings: first, the primary mechanism of photosynthetic limitation shifted from Ribulose-1,5-bisphosphate (RuBP) carboxylation (related to Vcmax) to RuBP regeneration (related to Jmax) in response to ECT, leading to decreased transition point (Ci-t and An-t) from RuBP carboxylation to regeneration; second, the increase in total leaf area in response to ECT more than compensated for the downregulation of leaf-area based photosynthesis, leading to greater biomass in ECT than in ACT. We proposed a new protocol for evaluating photosynthetic limitations by comparing the relative relationship between the transition point (Ci-t and An-t) and the photosynthetic rate at growth CO2 (Ci-g and An-g). Furthermore, we found that Jmax (RuBP regeneration) was the primary limitation to An under ECT.
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Affiliation(s)
- Lei Wang
- Faculty of Natural Resources Management, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B 5E1, Canada
- Department of Biotechnology, College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212003, China
| | - Jinping Zheng
- Faculty of Natural Resources Management, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B 5E1, Canada
- Forestry College, Beihua University, 3999 Binjiang East Road, Jilin, Jilin 132013, China
| | - Gerong Wang
- Faculty of Natural Resources Management, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B 5E1, Canada
- Forestry College, Beihua University, 3999 Binjiang East Road, Jilin, Jilin 132013, China
| | - Qing-Lai Dang
- Faculty of Natural Resources Management, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B 5E1, Canada
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20
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Kullberg AT, Slot M, Feeley KJ. Thermal optimum of photosynthesis is controlled by stomatal conductance and does not acclimate across an urban thermal gradient in six subtropical tree species. PLANT, CELL & ENVIRONMENT 2023; 46:831-849. [PMID: 36597283 DOI: 10.1111/pce.14533] [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: 09/20/2022] [Accepted: 12/29/2022] [Indexed: 06/17/2023]
Abstract
Modelling the response of plants to climate change is limited by our incomplete understanding of the component processes of photosynthesis and their temperature responses within and among species. For ≥20 individuals, each of six common subtropical tree species occurring across steep urban thermal gradients in Miami, Florida, USA, we determined rates of net photosynthesis (Anet ), maximum RuBP carboxylation, maximum RuBP regeneration and stomatal conductance, and modelled the optimum temperature (Topt ) and process rate of each parameter to address two questions: (1) Do the Topt of Anet (ToptA ) and the maximum Anet (Aopt ) of subtropical trees reflect acclimation to elevated growth temperatures? And (2) What limits Anet in subtropical trees? Against expectations, we did not find significant acclimation of ToptA , Aopt or the Topt of any of the underlying photosynthetic parameters to growth temperature in any of the focal species. Model selection for the single best predictor of Anet both across leaf temperatures and at ToptA revealed that the Anet of most trees was best predicted by stomatal conductance. Our findings are in accord with those of previous studies, especially in the tropics, that have identified stomatal conductance to be the most important factor limiting Anet , rather than biochemical thermal responses.
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Affiliation(s)
- Alyssa T Kullberg
- Department of Biology, University of Miami, Coral Gables, Florida, USA
| | - Martijn Slot
- Smithsonian Tropical Research Institute, Panama, Republic of Panama
| | - Kenneth J Feeley
- Department of Biology, University of Miami, Coral Gables, Florida, USA
- Fairchild Tropical Botanic Garden, Coral Gables, Florida, USA
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21
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Fang L, Martre P, Jin K, Du X, van der Putten PEL, Yin X, Struik PC. Neglecting acclimation of photosynthesis under drought can cause significant errors in predicting leaf photosynthesis in wheat. GLOBAL CHANGE BIOLOGY 2023; 29:505-521. [PMID: 36300859 PMCID: PMC10091787 DOI: 10.1111/gcb.16488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 09/14/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Extreme climatic events, such as heat waves, cold snaps and drought spells, related to global climate change, have become more frequent and intense in recent years. Acclimation of plant physiological processes to changes in environmental conditions is a key component of plant adaptation to climate change. We assessed the temperature response of leaf photosynthetic parameters in wheat grown under contrasting water regimes and growth temperatures (Tgrowth ). Two independent experiments were conducted under controlled conditions. In Experiment 1, two wheat genotypes were subjected to well-watered or drought-stressed treatments; in Experiment 2, the two water regimes combined with high, medium and low Tgrowth were imposed on one genotype. Parameters of a biochemical C3 -photosynthesis model were estimated at six leaf temperatures for each factor combination. Photosynthesis acclimated more to drought than to Tgrowth . Drought affected photosynthesis by lowering its optimum temperature (Topt ) and the values at Topt of light-saturated net photosynthesis, stomatal conductance, mesophyll conductance, the maximum rate of electron transport (Jmax ) and the maximum rate of carboxylation by Rubisco (Vcmax ). Topt for Vcmax was up to 40°C under well-watered conditions but 24-34°C under drought. The decrease in photosynthesis under drought varied among Tgrowth but was similar between genotypes. The temperature response of photosynthetic quantum yield under drought was partly attributed to photorespiration but more to alternative electron transport. All these changes in biochemical parameters could not be fully explained by the changed leaf nitrogen content. Further model analysis showed that both diffusional and biochemical parameters of photosynthesis and their thermal sensitivity acclimate little to Tgrowth , but acclimate considerably to drought and the combination of drought and Tgrowth . The commonly used modelling approaches, which typically consider the response of diffusional parameters, but ignore acclimation responses of biochemical parameters to drought and Tgrowth , strongly overestimate leaf photosynthesis under variable temperature and drought.
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Affiliation(s)
- Liang Fang
- Department of Plant Sciences, Centre for Crop Systems AnalysisWageningen University and ResearchWageningenThe Netherlands
| | - Pierre Martre
- LEPSEUniv Montpellier, INRAE, Institut Agro MontpellierMontpellierFrance
| | - Kaining Jin
- Department of Plant Sciences, Centre for Crop Systems AnalysisWageningen University and ResearchWageningenThe Netherlands
| | - Xinmiao Du
- Department of Plant Sciences, Centre for Crop Systems AnalysisWageningen University and ResearchWageningenThe Netherlands
| | - Peter E. L. van der Putten
- Department of Plant Sciences, Centre for Crop Systems AnalysisWageningen University and ResearchWageningenThe Netherlands
| | - Xinyou Yin
- Department of Plant Sciences, Centre for Crop Systems AnalysisWageningen University and ResearchWageningenThe Netherlands
| | - Paul C. Struik
- Department of Plant Sciences, Centre for Crop Systems AnalysisWageningen University and ResearchWageningenThe Netherlands
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22
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Didion‐Gency M, Gessler A, Buchmann N, Gisler J, Schaub M, Grossiord C. Impact of warmer and drier conditions on tree photosynthetic properties and the role of species interactions. THE NEW PHYTOLOGIST 2022; 236:547-560. [PMID: 35842790 PMCID: PMC9804646 DOI: 10.1111/nph.18384] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 07/07/2022] [Indexed: 06/01/2023]
Abstract
Increased temperature and prolonged soil moisture reduction have distinct impacts on tree photosynthetic properties. Yet, our knowledge of their combined effect is limited. Moreover, how species interactions alter photosynthetic responses to warming and drought remains unclear. Using mesocosms, we studied how photosynthetic properties of European beech and downy oak were impacted by multi-year warming and soil moisture reduction alone or combined, and how species interactions (intra- vs inter-specific interactions) modulated these effects. Warming of +5°C enhanced photosynthetic properties in oak but not beech, while moisture reduction decreased them in both species. Combined warming and moisture reduction reduced photosynthetic properties for both species, but no exacerbated effects were observed. Oak was less impacted by combined warming and limited moisture when interacting with beech than in intra-specific stands. For beech, species interactions had no impact on the photosynthetic responses to warming and moisture reduction, alone or combined. Warming had either no or beneficial effects on the photosynthetic properties, while moisture reduction and their combined effects strongly reduced photosynthetic responses. However, inter-specific interactions mitigated the adverse impacts of combined warming and drought in oak, thereby highlighting the need to deepen our understanding of the role of species interactions under climate change.
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Affiliation(s)
- Margaux Didion‐Gency
- Forest Dynamics Research Unit, Swiss Federal Institute for Forest, Snow and Landscape WSLCH‐8903BirmensdorfSwitzerland
| | - Arthur Gessler
- Forest Dynamics Research Unit, Swiss Federal Institute for Forest, Snow and Landscape WSLCH‐8903BirmensdorfSwitzerland
- Institute of Terrestrial Ecosystems, ETH ZurichCH‐8092ZurichSwitzerland
| | - Nina Buchmann
- Institute of Agricultural Sciences, ETH ZurichCH‐8092ZurichSwitzerland
| | - Jonas Gisler
- Forest Dynamics Research Unit, Swiss Federal Institute for Forest, Snow and Landscape WSLCH‐8903BirmensdorfSwitzerland
| | - Marcus Schaub
- Forest Dynamics Research Unit, Swiss Federal Institute for Forest, Snow and Landscape WSLCH‐8903BirmensdorfSwitzerland
| | - Charlotte Grossiord
- Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental EngineeringEPFLCH‐1015LausanneSwitzerland
- Community Ecology Unit, Swiss Federal Institute for Forest, Snow and Landscape WSLCH‐1015LausanneSwitzerland
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23
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Wittemann M, Andersson MX, Ntirugulirwa B, Tarvainen L, Wallin G, Uddling J. Temperature acclimation of net photosynthesis and its underlying component processes in four tropical tree species. TREE PHYSIOLOGY 2022; 42:1188-1202. [PMID: 35038330 PMCID: PMC9190752 DOI: 10.1093/treephys/tpac002] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 01/11/2022] [Indexed: 05/26/2023]
Abstract
The effect of temperature change on leaf physiology has been extensively studied in temperate trees and to some extent in boreal and tropical tree species. While increased temperature typically stimulates leaf CO2 assimilation and tree growth in high-altitude ecosystems, tropical species are often negatively affected. These trees may operate close to their temperature optima and have a limited thermal acclimation capacity due to low seasonal and historical variation in temperature. To test this hypothesis, we studied the extent to which the temperature sensitivities of leaf photosynthesis and respiration acclimate to growth temperature in four common African tropical tree species. Tree seedlings native to different altitudes and therefore adapted to different growth temperatures were cultivated at three different temperatures in climate-controlled chambers. We estimated the acclimation capacity of the temperature sensitivities of light-saturated net photosynthesis, the maximum rates of Rubisco carboxylation (Vcmax) and thylakoid electron transport (J), and dark respiration. Leaf thylakoid membrane lipid composition, nitrogen content and leaf mass per area were also analyzed. Our results showed that photosynthesis in tropical tree species acclimated to higher growth temperatures, but that this was weakest in the species originating from the coolest climate. The temperature optimum of J acclimated significantly in three species and variation in J was linked to changes in the thylakoid membrane lipid composition. For Vcmax, there was only evidence of significant acclimation of optimal temperature in the lowest elevation species. Respiration acclimated to maintain homeostasis at growth temperature in all four species. Our results suggest that the lowest elevation species is better physiologically adapted to acclimate to high growth temperatures than the highest elevation species, indicating a potential shift in competitive balance and tree community composition to the disadvantage of montane tree species in a warmer world.
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Affiliation(s)
- Maria Wittemann
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg SE-405 30, Sweden
- Gothenburg Global Biodiversity Centre (GGBC), University of Gothenburg, PO Box 461, Gothenburg SE-405 30, Sweden
- Department of Biology, College of Science and Technology, University of Rwanda, University Avenue, PO Box 117, Huye, Rwanda
| | - Mats X Andersson
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg SE-405 30, Sweden
| | - Bonaventure Ntirugulirwa
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg SE-405 30, Sweden
- Department of Biology, College of Science and Technology, University of Rwanda, University Avenue, PO Box 117, Huye, Rwanda
- Rwanda Agriculture and Resources Development Board (RAB), PO Box 5016, Kigali, Rwanda
| | - Lasse Tarvainen
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg SE-405 30, Sweden
| | - Göran Wallin
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg SE-405 30, Sweden
| | - Johan Uddling
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg SE-405 30, Sweden
- Gothenburg Global Biodiversity Centre (GGBC), University of Gothenburg, PO Box 461, Gothenburg SE-405 30, Sweden
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24
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Choury Z, Wujeska‐Klause A, Bourne A, Bown NP, Tjoelker MG, Medlyn BE, Crous KY. Tropical rainforest species have larger increases in temperature optima with warming than warm-temperate rainforest trees. THE NEW PHYTOLOGIST 2022; 234:1220-1236. [PMID: 35263440 PMCID: PMC9311211 DOI: 10.1111/nph.18077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 02/21/2022] [Indexed: 05/29/2023]
Abstract
While trees can acclimate to warming, there is concern that tropical rainforest species may be less able to acclimate because they have adapted to a relatively stable thermal environment. Here we tested whether the physiological adjustments to warming differed among Australian tropical, subtropical and warm-temperate rainforest trees. Photosynthesis and respiration temperature responses were quantified in six Australian rainforest seedlings of tropical, subtropical and warm-temperate climates grown across four growth temperatures in a glasshouse. Temperature-response models were fitted to identify mechanisms underpinning the response to warming. Tropical and subtropical species had higher temperature optima for photosynthesis (ToptA ) than temperate species. There was acclimation of ToptA to warmer growth temperatures. The rate of acclimation (0.35-0.78°C °C-1 ) was higher in tropical and subtropical than in warm-temperate trees and attributed to differences in underlying biochemical parameters, particularly increased temperature optima of Vcmax25 and Jmax25 . The temperature sensitivity of respiration (Q10 ) was 24% lower in tropical and subtropical compared with warm-temperate species. Overall, tropical and subtropical species had a similar capacity to acclimate to changes in growth temperature as warm-temperate species, despite being grown at higher temperatures. Quantifying the physiological acclimation in rainforests can improve accuracy of future climate predictions and assess their potential vulnerability to warming.
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Affiliation(s)
- Zineb Choury
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNSW2751Australia
| | - Agnieszka Wujeska‐Klause
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNSW2751Australia
- Urban StudiesSchool of Social SciencesWestern Sydney UniversityPenrithNSW2751Australia
| | - Aimee Bourne
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNSW2751Australia
| | - Nikki P. Bown
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNSW2751Australia
| | - Mark G. Tjoelker
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNSW2751Australia
| | - Belinda E. Medlyn
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNSW2751Australia
| | - Kristine Y. Crous
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNSW2751Australia
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25
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Crous KY, Uddling J, De Kauwe MG. Temperature responses of photosynthesis and respiration in evergreen trees from boreal to tropical latitudes. THE NEW PHYTOLOGIST 2022; 234:353-374. [PMID: 35007351 PMCID: PMC9994441 DOI: 10.1111/nph.17951] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 12/03/2021] [Indexed: 05/29/2023]
Abstract
Evergreen species are widespread across the globe, representing two major plant functional forms in terrestrial models. We reviewed and analysed the responses of photosynthesis and respiration to warming in 101 evergreen species from boreal to tropical biomes. Summertime temperatures affected both latitudinal gas exchange rates and the degree of responsiveness to experimental warming. The decrease in net photosynthesis at 25°C (Anet25 ) was larger with warming in tropical climates than cooler ones. Respiration at 25°C (R25 ) was reduced by 14% in response to warming across species and biomes. Gymnosperms were more sensitive to greater amounts of warming than broadleaved evergreens, with Anet25 and R25 reduced c. 30-40% with > 10°C warming. While standardised rates of carboxylation (Vcmax25 ) and electron transport (Jmax25 ) adjusted to warming, the magnitude of this adjustment was not related to warming amount (range 0.6-16°C). The temperature optimum of photosynthesis (ToptA ) increased on average 0.34°C per °C warming. The combination of more constrained acclimation of photosynthesis and increasing respiration rates with warming could possibly result in a reduced carbon sink in future warmer climates. The predictable patterns of thermal acclimation across biomes provide a strong basis to improve modelling predictions of the future terrestrial carbon sink with warming.
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Affiliation(s)
- Kristine Y. Crous
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityLocked Bag 1797PenrithNSW2751Australia
| | - Johan Uddling
- Department of Biological and Environmental SciencesUniversity of GothenburgPO Box 461GothenburgSE‐405 30Sweden
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26
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Zhu L, Zhang Y, Ye H, Li Y, Hu W, Du J, Zhao P. Variations in leaf and stem traits across two elevations in subtropical forests. FUNCTIONAL PLANT BIOLOGY : FPB 2022; 49:319-332. [PMID: 35157825 DOI: 10.1071/fp21220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 01/18/2022] [Indexed: 06/14/2023]
Abstract
Understanding the variations in plant traits across elevations may provide valuable insights into the species structure and function of forests and their responses to climate change. To explore the patterns of trait variation across elevations, we analysed 14 leaf and stem traits associated with resource acquisition and stress tolerance in Schima superba Gardner & Champion, Castanopsis chinensis (Sprengel) Hance, and Pinus massoniana Lambert trees at two elevations in a subtropical forest in southern China. Wood density increased, whereas crown width, leaf water potential at 0700 hours (Ψ L-0700 ), and leaf δ 18 O decreased in high-elevation plants. Vessel diameter, daily maximum sap flux density, leaf δ 13 C, and leaf C and N concentrations per unit mass were comparable across elevations. We found species-specific variations in specific leaf area, midday leaf water potential, and leaf P concentration across elevations. Decreasing crown width with increasing elevation was associated with decreasing leaf δ 18 O and Ψ L-0700 , suggesting that higher stomatal conductance may moderate the loss of carbon assimilation. We elucidated the adaptive strategies of plants in response to environmental change, and showed that physiological traits varied in coordination with structural traits. Future studies incorporating multi-dimensional trait analyses can improve our understanding of the responses of forest ecosystems to climate change and global warming.
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Affiliation(s)
- Liwei Zhu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; and Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou 510650, China; and Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Yaxing Zhang
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Huiying Ye
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Yanqiong Li
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Weiting Hu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Jie Du
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Ping Zhao
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; and Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou 510650, China; and Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
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