1
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Truong AT, Edwards MS, Long JD. Season-specific impacts of climate change on canopy-forming seaweed communities. Ecol Evol 2024; 14:e10947. [PMID: 38357589 PMCID: PMC10864935 DOI: 10.1002/ece3.10947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 11/22/2023] [Accepted: 12/06/2023] [Indexed: 02/16/2024] Open
Abstract
Understory assemblages associated with canopy-forming species such as trees, kelps, and rockweeds should respond strongly to climate stressors due to strong canopy-understory interactions. Climate change can directly and indirectly modify these assemblages, particularly during more stressful seasons and climate scenarios. However, fully understanding the seasonal impacts of different climate conditions on canopy-reliant assemblages is difficult due to a continued emphasis on studying single-species responses to a single future climate scenario during a single season. To examine these emergent effects, we used mesocosm experiments to expose seaweed assemblages associated with the canopy-forming golden rockweed, Silvetia compressa, to elevated temperature and pCO2 conditions reflecting two projected greenhouse emission scenarios (RCP 2.6 [low] & RCP 4.5 [moderate]). Assemblages were grown in the presence and absence of Silvetia, and in two seasons. Relative to ambient conditions, predicted climate scenarios generally suppressed Silvetia biomass and photosynthetic efficiency. However, these effects varied seasonally-both future scenarios reduced Silvetia biomass in summer, but only the moderate scenario did so in winter. These reductions shifted the assemblage, with more extreme shifts occurring in summer. Contrarily, future scenarios did not shift assemblages within Silvetia Absent treatments, suggesting that climate primarily affected assemblages indirectly through changes in Silvetia. Mesocosm experiments were coupled with a field Silvetia removal experiment to simulate the effects of climate-mediated Silvetia loss on natural assemblages. Consistent with the mesocosm experiment, Silvetia loss resulted in season-specific assemblage shifts, with weaker effects observed in winter. Together, our study supports the hypotheses that climate-mediated changes to canopy-forming species can indirectly affect the associated assemblage, and that these effects vary seasonally. Such seasonality is important to consider as it may provide periods of recovery when conditions are less stressful, especially if we can reduce the severity of future climate scenarios.
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Affiliation(s)
- Anthony T. Truong
- Department of BiologySan Diego State UniversitySan DiegoCaliforniaUSA
| | | | - Jeremy D. Long
- Department of BiologySan Diego State UniversitySan DiegoCaliforniaUSA
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2
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Van Nuland ME, Daws SC, Bailey JK, Schweitzer JA, Busby PE, Peay KG. Above- and belowground fungal biodiversity of Populus trees on a continental scale. Nat Microbiol 2023; 8:2406-2419. [PMID: 37973868 DOI: 10.1038/s41564-023-01514-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 10/04/2023] [Indexed: 11/19/2023]
Abstract
Understanding drivers of terrestrial fungal communities over large scales is an important challenge for predicting the fate of ecosystems under climate change and providing critical ecological context for bioengineering plant-microbe interactions in model systems. We conducted an extensive molecular and microscopy field study across the contiguous United States measuring natural variation in the Populus fungal microbiome among tree species, plant niche compartments and key symbionts. Our results show clear biodiversity hotspots and regional endemism of Populus-associated fungal communities explained by a combination of climate, soil and geographic factors. Modelling climate change impacts showed a deterioration of Populus mycorrhizal associations and an increase in potentially pathogenic foliar endophyte diversity and prevalence. Geographic differences among these symbiont groups in their sensitivity to environmental change are likely to influence broader forest health and ecosystem function. This dataset provides an above- and belowground atlas of Populus fungal biodiversity at a continental scale.
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Affiliation(s)
- Michael E Van Nuland
- Department of Biology, Stanford University, Stanford, CA, USA.
- Society for the Protection of Underground Networks, SPUN, Dover, DE, USA.
| | - S Caroline Daws
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Joseph K Bailey
- Ecology and Evolutionary Biology Department, University of Tennessee, Knoxville, TN, USA
| | - Jennifer A Schweitzer
- Ecology and Evolutionary Biology Department, University of Tennessee, Knoxville, TN, USA
| | - Posy E Busby
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, USA
| | - Kabir G Peay
- Department of Biology, Stanford University, Stanford, CA, USA
- Department of Earth System Science, Stanford University, Stanford, CA, USA
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3
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Moran ME, Aparecido LMT, Koepke DF, Cooper HF, Doughty CE, Gehring CA, Throop HL, Whitham TG, Allan GJ, Hultine KR. Limits of thermal and hydrological tolerance in a foundation tree species (Populus fremontii) in the desert southwestern United States. THE NEW PHYTOLOGIST 2023; 240:2298-2311. [PMID: 37680030 DOI: 10.1111/nph.19247] [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: 05/26/2023] [Accepted: 08/05/2023] [Indexed: 09/09/2023]
Abstract
Populus fremontii is among the most dominant, and ecologically important riparian tree species in the western United States and can thrive in hyper-arid riparian corridors. Yet, P. fremontii forests have rapidly declined over the last decade, particularly in places where temperatures sometimes exceed 50°C. We evaluated high temperature tolerance of leaf metabolism, leaf thermoregulation, and leaf hydraulic function in eight P. fremontii populations spanning a 5.3°C mean annual temperature gradient in a well-watered common garden, and at source locations throughout the lower Colorado River Basin. Two major results emerged. First, despite having an exceptionally high Tcrit (the temperature at which Photosystem II is disrupted) relative to other tree taxa, recent heat waves exceeded Tcrit , requiring evaporative leaf cooling to maintain leaf-to-air thermal safety margins. Second, in midsummer, genotypes from the warmest locations maintained lower midday leaf temperatures, a higher midday stomatal conductance, and maintained turgor pressure at lower water potentials than genotypes from more temperate locations. Taken together, results suggest that under well-watered conditions, P. fremontii can regulate leaf temperature below Tcrit along the warm edge of its distribution. Nevertheless, reduced Colorado River flows threaten to lower water tables below levels needed for evaporative cooling during episodic heat waves.
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Affiliation(s)
- Madeline E Moran
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Luiza M T Aparecido
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, 85287, USA
| | - Dan F Koepke
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, AZ, 85008, USA
| | - Hillary F Cooper
- Department of Biological Sciences and Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Christopher E Doughty
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Catherine A Gehring
- Department of Biological Sciences and Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Heather L Throop
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, 85287, USA
| | - Thomas G Whitham
- Department of Biological Sciences and Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Gerard J Allan
- Department of Biological Sciences and Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Kevin R Hultine
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, AZ, 85008, USA
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4
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Leites L, Benito Garzón M. Forest tree species adaptation to climate across biomes: Building on the legacy of ecological genetics to anticipate responses to climate change. GLOBAL CHANGE BIOLOGY 2023; 29:4711-4730. [PMID: 37029765 DOI: 10.1111/gcb.16711] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 01/30/2023] [Accepted: 03/17/2023] [Indexed: 06/19/2023]
Abstract
Intraspecific variation plays a critical role in extant and future forest responses to climate change. Forest tree species with wide climatic niches rely on the intraspecific variation resulting from genetic adaptation and phenotypic plasticity to accommodate spatial and temporal climate variability. A centuries-old legacy of forest ecological genetics and provenance trials has provided a strong foundation upon which to continue building on this knowledge, which is critical to maintain climate-adapted forests. Our overall objective is to understand forest trees intraspecific responses to climate across species and biomes, while our specific objectives are to describe ecological genetics models used to build our foundational knowledge, summarize modeling approaches that have expanded the traditional toolset, and extensively review the literature from 1994 to 2021 to highlight the main contributions of this legacy and the new analyzes of provenance trials. We reviewed 103 studies comprising at least three common gardens, which covered 58 forest tree species, 28 of them with range-wide studies. Although studies using provenance trial data cover mostly commercially important forest tree species from temperate and boreal biomes, this synthesis provides a global overview of forest tree species adaptation to climate. We found that evidence for genetic adaptation to local climate is commonly present in the species studied (79%), being more common in conifers (87.5%) than in broadleaf species (67%). In 57% of the species, clines in fitness-related traits were associated with temperature variables, in 14% of the species with precipitation, and in 25% of the species with both. Evidence of adaptation lags was found in 50% of the species with range-wide studies. We conclude that ecological genetics models and analysis of provenance trial data provide excellent insights on intraspecific genetic variation, whereas the role and limits of phenotypic plasticity, which will likely determine the fate of extant forests, is vastly understudied.
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Affiliation(s)
- Laura Leites
- Department of Ecosystem Science and Management, Penn State University, University Park, Pennsylvania, USA
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5
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Blonder BW, Brodrick PG, Chadwick KD, Carroll E, Cruz-de Hoyos RM, Expósito-Alonso M, Hateley S, Moon M, Ray CA, Tran H, Walton JA. Climate lags and genetics determine phenology in quaking aspen (Populus tremuloides). THE NEW PHYTOLOGIST 2023; 238:2313-2328. [PMID: 36856334 DOI: 10.1111/nph.18850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 02/19/2023] [Indexed: 05/19/2023]
Abstract
Spatiotemporal patterns of phenology may be affected by mosaics of environmental and genetic variation. Environmental drivers may have temporally lagged impacts, but patterns and mechanisms remain poorly known. We combine multiple genomic, remotely sensed, and physically modeled datasets to determine the spatiotemporal patterns and drivers of canopy phenology in quaking aspen, a widespread clonal dioecious tree species with diploid and triploid cytotypes. We show that over 391 km2 of southwestern Colorado: greenup date, greendown date, and growing season length vary by weeks and differ across sexes, cytotypes, and genotypes; phenology has high phenotypic plasticity and heritabilities of 31-61% (interquartile range); and snowmelt date, soil moisture, and air temperature predict phenology, at temporal lags of up to 3 yr. Our study shows that lagged environmental effects are needed to explain phenological variation and that the effect of cytotype on phenology is obscured by its correlation with topography. Phenological patterns are consistent with responses to multiyear accumulation of carbon deficit or hydraulic damage.
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Affiliation(s)
- Benjamin W Blonder
- Department of Environmental Science, Policy, and Management, University of California - Berkeley, Berkeley, CA, 94720, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO, 81224, USA
| | - Philip G Brodrick
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91109, USA
| | - K Dana Chadwick
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91109, USA
| | - Erin Carroll
- Department of Environmental Science, Policy, and Management, University of California - Berkeley, Berkeley, CA, 94720, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO, 81224, USA
| | - Roxanne M Cruz-de Hoyos
- Department of Environmental Science, Policy, and Management, University of California - Berkeley, Berkeley, CA, 94720, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO, 81224, USA
| | | | - Shannon Hateley
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Minkyu Moon
- Department of Earth & Environment, Boston University, Boston, MA, 02215, USA
| | - Courtenay A Ray
- Department of Environmental Science, Policy, and Management, University of California - Berkeley, Berkeley, CA, 94720, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO, 81224, USA
| | - Hoang Tran
- Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ, 08540, USA
- Atmospheric Sciences & Global Change Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - James A Walton
- Molecular Ecology Laboratory, Department of Wildland Resources, Utah State University, Logan, UT, 84322, USA
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6
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Palmquist EC, Ogle K, Whitham TG, Allan GJ, Shafroth PB, Butterfield BJ. Provenance, genotype, and flooding influence growth and resource acquisition characteristics in a clonal, riparian shrub. AMERICAN JOURNAL OF BOTANY 2023; 110:e16115. [PMID: 36462152 DOI: 10.1002/ajb2.16115] [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: 07/01/2022] [Revised: 11/23/2022] [Accepted: 11/23/2022] [Indexed: 06/17/2023]
Abstract
PREMISE Riparian plants can exhibit intraspecific phenotypic variability across the landscape related to temperature and flooding gradients. Phenotypes that vary across a climate gradient are often partly genetically determined and may differ in their response to inundation. Changes to inundation patterns across a climate gradient could thus result in site-specific inundation responses. Phenotypic variability is more often studied in riparian trees, yet riparian shrubs are key elements of riparian systems and may differ from trees in phenotypic variability and environmental responses. METHODS We tested whether individuals of a clonal, riparian shrub, Pluchea sericea, collected from provenances spanning a temperature gradient differed in their phenotypes and responses to inundation and to what degree any differences were related to genotype. Plants were subjected to different inundation depths and a subset genotyped. Variables related to growth and resource acquisition were measured and analyzed using hierarchical, multivariate Bayesian linear regressions. RESULTS Individuals from different provenances differed in their phenotypes, but not in their response to inundation. Phenotypes were not related to provenance temperature but were partially governed by genotype. Growth was more strongly influenced by inundation, while resource acquisition was more strongly controlled by genotype. CONCLUSIONS Growth and resource acquisition responses in a clonal, riparian shrub are affected by changes to inundation and plant demographics in unique ways. Shrubs appear to differ from trees in their responses to environmental change. Understanding environmental effects on shrubs separately from those of trees will be a key part of evaluating impacts of environmental change on riparian ecosystems.
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Affiliation(s)
- Emily C Palmquist
- U.S. Geological Survey, Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, 2255 N Gemini Dr, Flagstaff, AZ, 86001, USA
- Department of Biological Sciences, Northern Arizona University, Box 5640, Flagstaff, AZ, 86011, USA
| | - Kiona Ogle
- School of Informatics, Computing and Cyber Systems, Northern Arizona University, Box 5693, Flagstaff, AZ, 86011, USA
| | - Thomas G Whitham
- Department of Biological Sciences, Northern Arizona University, Box 5640, Flagstaff, AZ, 86011, USA
- Center for Adaptable Western Landscapes (CAWL), Northern Arizona University, Box 5640, Flagstaff, AZ, 86011, USA
| | - Gerard J Allan
- Department of Biological Sciences, Northern Arizona University, Box 5640, Flagstaff, AZ, 86011, USA
- Center for Adaptable Western Landscapes (CAWL), Northern Arizona University, Box 5640, Flagstaff, AZ, 86011, USA
| | - Patrick B Shafroth
- U.S. Geological Survey, Fort Collins Science Center, 2150 Centre Ave., Bldg C, Fort Collins, CO, 80526, USA
| | - Bradley J Butterfield
- Department of Biological Sciences, Northern Arizona University, Box 5640, Flagstaff, AZ, 86011, USA
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7
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Snyder KA, Robinson SA, Schmidt S, Hultine KR. Stable isotope approaches and opportunities for improving plant conservation. CONSERVATION PHYSIOLOGY 2022; 10:coac056. [PMID: 35966756 PMCID: PMC9367551 DOI: 10.1093/conphys/coac056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 04/15/2021] [Accepted: 08/01/2022] [Indexed: 06/01/2023]
Abstract
Successful conservation of threatened species and ecosystems in a rapidly changing world requires scientifically sound decision-making tools that are readily accessible to conservation practitioners. Physiological applications that examine how plants and animals interact with their environment are now widely used when planning, implementing and monitoring conservation. Among these tools, stable-isotope physiology is a potentially powerful, yet under-utilized cornerstone of current and future conservation efforts of threatened and endangered plants. We review the underlying concepts and theory of stable-isotope physiology and describe how stable-isotope applications can support plant conservation. We focus on stable isotopes of carbon, hydrogen, oxygen and nitrogen to address plant ecophysiological responses to changing environmental conditions across temporal scales from hours to centuries. We review examples from a broad range of plant taxa, life forms and habitats and provide specific examples where stable-isotope analysis can directly improve conservation, in part by helping identify resilient, locally adapted genotypes or populations. Our review aims to provide a guide for practitioners to easily access and evaluate the information that can be derived from stable-isotope signatures, their limitations and how stable isotopes can improve conservation efforts.
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Affiliation(s)
- Keirith A Snyder
- Corresponding author: USDA Agricultural Research Service, Great Basin Rangelands Research Unit, Reno,
920 Valley Road, NV 89512, USA.
| | - Sharon A Robinson
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia
- Securing Antarctica’s Environmental Future, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Susanne Schmidt
- School of Agriculture and Food Sciences, The University of Queensland, Building 62, Brisbane Queensland 4075, Australia
| | - Kevin R Hultine
- Department of Research, Conservation and Collections, Desert Botanical Garden, 1201 Galvin Parkway, Phoenix, AZ 85008, USA
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8
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Cooper HF, Best RJ, Andrews LV, Corbin JPM, Garthwaite I, Grady KC, Gehring CA, Hultine KR, Whitham TG, Allan GJ. Evidence of climate-driven selection on tree traits and trait plasticity across the climatic range of a riparian foundation species. Mol Ecol 2022; 31:5024-5040. [PMID: 35947510 DOI: 10.1111/mec.16645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 07/28/2022] [Accepted: 08/01/2022] [Indexed: 11/30/2022]
Abstract
Selection on quantitative traits by heterogeneous climatic conditions can lead to substantial trait variation across a species range. In the context of rapidly changing environments, however, it is equally important to understand selection on trait plasticity. To evaluate the role of selection in driving divergences in traits and their associated plasticities within a widespread species, we compared molecular and quantitative trait variation in Populus fremontii (Fremont cottonwood), a foundation riparian distributed throughout Arizona. Using SNP data and genotypes from 16 populations reciprocally planted in three common gardens, we first performed QST -FST analyses to detect selection on traits and trait plasticity. We then explored the environmental drivers of selection using trait-climate and plasticity-climate regressions. Three major findings emerged: 1) There was significant genetic variation in traits expressed in each of the common gardens and in the phenotypic plasticity of traits across gardens, both of which were heritable. 2) Based on QST -FST comparisons, there was evidence of selection in all traits measured; however, this result varied from no effect in one garden to highly significant in another, indicating that detection of past selection is environmentally dependent. We also found strong evidence of divergent selection on plasticity across environments for two traits. 3) Traits and/or their plasticity were often correlated with population source climate (R2 up to 0.77 and 0.66, respectively). These results suggest that steep climate gradients across the Southwest have played a major role in shaping the evolution of divergent phenotypic responses in populations and genotypes now experiencing climate change.
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Affiliation(s)
- Hillary F Cooper
- Department of Biological Science, Northern Arizona University, Flagstaff, AZ, USA.,Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, USA
| | - Rebecca J Best
- School of Earth and Sustainability, Northern Arizona University, Flagstaff, AZ, USA
| | - Lela V Andrews
- Department of Biological Science, Northern Arizona University, Flagstaff, AZ, USA
| | - Jaclyn P M Corbin
- Department of Biological Science, Northern Arizona University, Flagstaff, AZ, USA.,Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, USA
| | - Iris Garthwaite
- School of Earth and Sustainability, Northern Arizona University, Flagstaff, AZ, USA
| | - Kevin C Grady
- School of Forestry, Northern Arizona University, Flagstaff, AZ, USA
| | - Catherine A Gehring
- Department of Biological Science, Northern Arizona University, Flagstaff, AZ, USA.,Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, USA
| | - Kevin R Hultine
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, AZ, USA
| | - Thomas G Whitham
- Department of Biological Science, Northern Arizona University, Flagstaff, AZ, USA.,Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, USA
| | - Gerard J Allan
- Department of Biological Science, Northern Arizona University, Flagstaff, AZ, USA.,Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, USA
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9
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Eisenring M, Best RJ, Zierden MR, Cooper HF, Norstrem MA, Whitham TG, Grady K, Allan GJ, Lindroth RL. Genetic divergence along a climate gradient shapes chemical plasticity of a foundation tree species to both changing climate and herbivore damage. GLOBAL CHANGE BIOLOGY 2022; 28:4684-4700. [PMID: 35596651 DOI: 10.1111/gcb.16275] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/21/2022] [Indexed: 06/15/2023]
Abstract
Climate change is threatening the persistence of many tree species via independent and interactive effects on abiotic and biotic conditions. In addition, changes in temperature, precipitation, and insect attacks can alter the traits of these trees, disrupting communities and ecosystems. For foundation species such as Populus, phytochemical traits are key mechanisms linking trees with their environment and are likely jointly determined by interactive effects of genetic divergence and variable environments throughout their geographic range. Using reciprocal Fremont cottonwood (Populus fremontii) common gardens along a steep climatic gradient, we explored how environment (garden climate and simulated herbivore damage) and genetics (tree provenance and genotype) affect both foliar chemical traits and the plasticity of these traits. We found that (1) Constitutive and plastic chemical responses to changes in garden climate and damage varied among defense compounds, structural compounds, and leaf nitrogen. (2) For both defense and structural compounds, plastic responses to different garden climates depended on the climate in which a population or genotype originated. Specifically, trees originating from cool provenances showed higher defense plasticity in response to climate changes than trees from warmer provenances. (3) Trees from cool provenances growing in cool garden conditions expressed the lowest constitutive defense levels but the strongest induced (plastic) defenses in response to damage. (4) The combination of hot garden conditions and simulated herbivory switched the strategy used by these genotypes, increasing constitutive defenses but erasing the capacity for induction after damage. Because Fremont cottonwood chemistry plays a major role in shaping riparian communities and ecosystems, the effects of changes in phytochemical traits can be wide reaching. As the southwestern US is confronted with warming temperatures and insect outbreaks, these results improve our capacity to predict ecosystem consequences of climate change and inform selection of tree genotypes for conservation and restoration purposes.
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Affiliation(s)
- Michael Eisenring
- Department of Entomology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Forest Entomology, Swiss Federal Research Institute for Forest, Snow, and Landscape Research WSL, Zurich, Switzerland
| | - Rebecca J Best
- School of Earth and Sustainability, Northern Arizona University, Flagstaff, Arizona, USA
| | - Mark R Zierden
- Department of Entomology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Hillary F Cooper
- Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, Arizona, USA
| | - Madelyn A Norstrem
- School of Earth and Sustainability, Northern Arizona University, Flagstaff, Arizona, USA
| | - Thomas G Whitham
- Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Kevin Grady
- School of Forestry, Northern Arizona University, Flagstaff, Arizona, USA
| | - Gerard J Allan
- Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Richard L Lindroth
- Department of Entomology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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10
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Blasini DE, Koepke DF, Bush SE, Allan GJ, Gehring CA, Whitham TG, Day TA, Hultine KR. Tradeoffs between leaf cooling and hydraulic safety in a dominant arid land riparian tree species. PLANT, CELL & ENVIRONMENT 2022; 45:1664-1681. [PMID: 35147232 DOI: 10.1111/pce.14292] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 02/07/2022] [Indexed: 06/14/2023]
Abstract
Leaf carbon gain optimization in hot environments requires balancing leaf thermoregulation with avoiding excessive water loss via transpiration and hydraulic failure. The tradeoffs between leaf thermoregulation and transpirational water loss can determine the ecological consequences of heat waves that are increasing in frequency and intensity. We evaluated leaf thermoregulation strategies in warm- (>40°C maximum summer temperature) and cool-adapted (<40°C maximum summer temperature) genotypes of the foundation tree species, Populus fremontii, using a common garden near the mid-elevational point of its distribution. We measured leaf temperatures and assessed three modes of leaf thermoregulation: leaf morphology, midday canopy stomatal conductance and stomatal sensitivity to vapour pressure deficit. Data were used to parameterize a leaf energy balance model to estimate contrasts in midday leaf temperature in warm- and cool-adapted genotypes. Warm-adapted genotypes had 39% smaller leaves and 38% higher midday stomatal conductance, reflecting a 3.8°C cooler mean leaf temperature than cool-adapted genotypes. Leaf temperatures modelled over the warmest months were on average 1.1°C cooler in warm- relative to cool-adapted genotypes. Results show that plants adapted to warm environments are predisposed to tightly regulate leaf temperatures during heat waves, potentially at an increased risk of hydraulic failure.
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Affiliation(s)
- Davis E Blasini
- School of Life Sciences, Arizona State University, Tempe, Arizona, USA
| | - Dan F Koepke
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, Arizona, USA
| | - Susan E Bush
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, Arizona, USA
| | - Gerard J Allan
- Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Catherine A Gehring
- Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Thomas G Whitham
- Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, Arizona, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Thomas A Day
- School of Life Sciences, Arizona State University, Tempe, Arizona, USA
| | - Kevin R Hultine
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, Arizona, USA
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11
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Guo JS, Bush SE, Hultine KR. Temporal variation in stomatal sensitivity to vapor pressure deficit in western riparian forests. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14066] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jessica S. Guo
- Arizona Experiment Station, College of Agriculture and Life Sciences University of Arizona Tucson, AZ 85721 USA
| | - Susan E. Bush
- Department of Biological Sciences University of Utah Salt Lake City, UT 84112 USA
| | - Kevin R. Hultine
- Department of Research, Conservation, and Collections, Desert Botanical Garden Phoenix, AZ 85008 USA
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12
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Abstract
As the effects of climate change accumulate and intensify, resource managers juggle existing goals and new mandates to operationalize adaptation. Fire managers contend with the direct effects of climate change on resources in addition to climate-induced disruptions to fire regimes and subsequent ecosystem effects. In systems stressed by warming and drying, increased fire activity amplifies the pace of change and scale of severe disturbance events, heightening the urgency for management action. Fire managers are asked to integrate information on climate impacts with their professional expertise to determine how to achieve management objectives in a changing climate with altered fire regimes. This is a difficult task, and managers need support as they incorporate climate adaptation into planning and operations. We present a list of adaptation strategies and approaches specific to fire and climate based on co-produced knowledge from a science–management partnership and pilot-tested in a two-day workshop with natural resource managers and regional stakeholders. This “menu” is a flexible and useful tool for fire managers who need to connect the dots between fire ecology, climate science, adaptation intent, and management implementation. It was created and tested as part of an adaptation framework used widely across the United States and should be applicable and useful in many fire-prone forest ecosystems.
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13
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Jeplawy JR, Cooper HF, Marks J, Lindroth RL, Andrews MI, Compson ZG, Gehring C, Hultine KR, Grady K, Whitham TG, Allan GJ, Best RJ. Plastic responses to hot temperatures homogenize riparian leaf litter, speed decomposition, and reduce detritivores. Ecology 2021; 102:e03461. [PMID: 34236702 DOI: 10.1002/ecy.3461] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 04/12/2021] [Accepted: 05/13/2021] [Indexed: 01/10/2023]
Abstract
Efforts to maintain the function of critical ecosystems under climate change often begin with foundation species. In the southwestern United States, cottonwood trees support diverse communities in riparian ecosystems that are threatened by rising temperatures. Genetic variation within cottonwoods shapes communities and ecosystems, but these effects may be modified by phenotypic plasticity, where genotype traits change in response to environmental conditions. Here, we investigated plasticity in Fremont cottonwood (Populus fremontii) leaf litter traits as well as the consequences of plasticity for riparian ecosystems. We used three common gardens each planted with genotypes from six genetically divergent populations spanning a 12°C temperature gradient, and a decomposition experiment in a common stream environment. We found that leaf litter area, specific leaf area, and carbon to nitrogen ratio (C:N) were determined by interactions between genetics and growing environment, as was the subsequent rate of litter decomposition. Most of the genetic variation in leaf litter traits appeared among rather than within source populations with distinct climate histories. Source populations from hotter climates generally produced litter that decomposed more quickly, but plasticity varied the magnitude of this effect. We also found that hotter growing conditions reduced the variation in litter traits produced across genotypes, homogenizing the litter inputs to riparian ecosystems. All genotypes in the hottest garden produced comparatively small leaves that decomposed quickly and supported lower abundances of aquatic invertebrates, whereas the same genotypes in the coldest garden produced litter with distinct morphologies and decomposition rates. Our results suggest that plastic responses to climate stress may constrict the expression of genetic variation in predictable ways that impact communities and ecosystems. Understanding these interactions between genetic and environmental variation is critical to our ability to plan for the role of foundation species when managing and restoring riparian ecosystems in a warming world.
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Affiliation(s)
- Joann R Jeplawy
- School of Earth and Sustainability, Northern Arizona University, Flagstaff, Arizona, 86011, USA.,Tetra Tech, Inc., Denver, Colorado, 80202, USA
| | - Hillary F Cooper
- School of Earth and Sustainability, Northern Arizona University, Flagstaff, Arizona, 86011, USA.,Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, 86011, USA.,Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, Arizona, 86011, USA
| | - Jane Marks
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, 86011, USA.,Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, Arizona, 86011, USA
| | - Richard L Lindroth
- Department of Entomology, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Morgan I Andrews
- School of Earth and Sustainability, Northern Arizona University, Flagstaff, Arizona, 86011, USA
| | - Zacchaeus G Compson
- Department of Biological Sciences, Advanced Environmental Research Institute, University of North Texas, Denton, Texas, 76203, USA
| | - Catherine Gehring
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, 86011, USA.,Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, Arizona, 86011, USA
| | - Kevin R Hultine
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, Arizona, 85008, USA
| | - Kevin Grady
- Department of Forestry, Northern Arizona University, Flagstaff, Arizona, 86011, USA
| | - Thomas G Whitham
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, 86011, USA.,Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, Arizona, 86011, USA
| | - Gerard J Allan
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, 86011, USA.,Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, Arizona, 86011, USA
| | - Rebecca J Best
- School of Earth and Sustainability, Northern Arizona University, Flagstaff, Arizona, 86011, USA
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14
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Moler ERV, Kolb T, Brady A, Palmiero BN, Wallace TR, Waring KM, Whipple AV. Plant developmental stage influences responses of Pinus strobiformis seedlings to experimental warming. PLANT-ENVIRONMENT INTERACTIONS (HOBOKEN, N.J.) 2021; 2:148-164. [PMID: 37283863 PMCID: PMC10168050 DOI: 10.1002/pei3.10055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 04/17/2021] [Accepted: 04/23/2021] [Indexed: 06/08/2023]
Abstract
Seedling emergence, survival, morphological and physiological traits, and oxidative stress resistance of southwestern white pine (Pinus strobiformis Engelm.) were studied in response to warming treatments applied during embryogenesis, germination, and early seedling growth. Daytime air temperature surrounding cones in tree canopies was warmed by +2.1°C during embryo development. Resulting seeds and seedlings were assigned to three thermal regimes in growth chambers, with each regime separated by 4°C to encompass the wide range of temperatures observed over space and time across the species' range, plus the effect of heat waves coupled with a high carbon emissions scenario of climate warming. The embryo warming treatment reduced percent seedling emergence in all germination and growth environments and reduced mortality of seedlings grown in the warmest environment. Warm thermal regimes during early seedling growth increased subsequent seedling resistance to oxidative stress and transpirational water use. Experimental warming during seed development, germination, and seedling growth affected seedling emergence and survival. Oxidative stress resistance, morphology, and water relations were affected only by warming imposed during germination and seedling growth. This work explores potential outcomes of climate warming on multiple dimensions of seedling performance and uniquely illustrates that plant responses to heat vary with plant developmental stage in addition to the magnitude of temperature change.
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Affiliation(s)
| | - Thomas Kolb
- School of ForestryNorthern Arizona UniversityFlagstaffAZUSA
| | - Anne Brady
- Department of Biological SciencesNorthern Arizona UniversityFlagstaffAZUSA
| | | | | | | | - Amy Vaughn Whipple
- Department of Biological SciencesNorthern Arizona UniversityFlagstaffAZUSA
- Center for Adaptive Western LandscapesNorthern Arizona UniversityFlagstaffAZUSA
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