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Willis AB, Ermolaeva E, Zyck A, Rognstad R, Davis S, Hilbish TJ. Integration of natural selection across the life cycle stabilizes a marine mussel hybrid zone. Ecol Evol 2024; 14:e11086. [PMID: 38469047 PMCID: PMC10925496 DOI: 10.1002/ece3.11086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 02/12/2024] [Accepted: 02/16/2024] [Indexed: 03/13/2024] Open
Abstract
Hybridization among related species is now recognized as common but it remains unclear how hybrid zones persist for prolonged periods. Here, we test the hypothesis that selection in different components of the life cycle may stabilize a hybrid zone. A hybrid zone occurs in southwest England between the marine mussels Mytilus edulis and M. galloprovincialis. Previous studies have found strong directional selection against alleles from M. edulis occurs among hybrids in the adult stage. Traditional hybrid zone models argue that alleles that are selected within the hybrid zone are replaced by migration from neighboring parental population into the hybrid zone. In this system, however, migration occurs out of this hybrid zone into neighboring parental populations. This hybrid zone should therefore be unstable and dissipate, yet this zone has persisted for more than 30 years. We tested and rejected the hypothesis that differences in fecundity may select for M. edulis alleles within this hybrid zone and thus counter the selection observed against these alleles among adults. We also tested the hypothesis that selection during the larval stage may counter selection against M. edulis alleles in the adult stage. We found that selection favors M. edulis alleles during the veliger stage of larval development. The direction and strength of selection during the larval stage are sufficient to counter strong selection during the adult portion of the life cycle. This hybrid zone is stabilized by opposing forms of directional selection operating in different portions of the life cycle.
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Affiliation(s)
- Allison B. Willis
- Department of Biological SciencesUniversity of South CarolinaColumbiaSouth CarolinaUSA
| | - Evgeniya Ermolaeva
- Department of Biological SciencesUniversity of South CarolinaColumbiaSouth CarolinaUSA
| | - Amaelia Zyck
- Department of Biological SciencesUniversity of South CarolinaColumbiaSouth CarolinaUSA
| | - Rhiannon Rognstad
- Department of Biological SciencesUniversity of South CarolinaColumbiaSouth CarolinaUSA
| | - Shannon Davis
- Department of Biological SciencesUniversity of South CarolinaColumbiaSouth CarolinaUSA
| | - Thomas J. Hilbish
- Department of Biological SciencesUniversity of South CarolinaColumbiaSouth CarolinaUSA
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Hearon CM, Peters K, Dias KA, Macnamara JP, Marshall JET, Campain J, Martin D, Marshal‐Goebel K, Levine BD. Assessment of venous pressure by compression sonography of the internal jugular vein during 3 days of bed rest. Exp Physiol 2023; 108:1560-1568. [PMID: 37824038 PMCID: PMC10988448 DOI: 10.1113/ep091372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 09/28/2023] [Indexed: 10/13/2023]
Abstract
Compression sonography has been proposed as a method for non-invasive measurement of venous pressures during spaceflight, but initial reports of venous pressure measured by compression ultrasound conflict with prior reports of invasively measured central venous pressure (CVP). The aim of this study is to determine the agreement of compression sonography of the internal jugular vein (IJVP) with invasive measures of CVP over a range of pressures relevant to microgravity exposure. Ten healthy volunteers (18-55 years, five female) completed two 3-day sessions of supine bed rest to simulate microgravity. IJVP and CVP were measured in the seated position, and in the supine position throughout 3 days of bed rest. The range of CVP recorded was in line with previous reports of CVP during changes in posture on Earth and in microgravity. The correlation between IJVP and CVP was poor when measured during spontaneous breathing (r = 0.29; R2 = 0.09; P = 0.0002; standard error of the estimate (SEE) = 3.0 mmHg) or end-expiration CVP (CVPEE ; r = 0.19; R2 = 0.04; P = 0.121; SEE = 3.0 mmHg). There was a modest correlation between the change in CVP and the change in IJVP for both spontaneous ΔCVP (r = 0.49; R2 = 0.24; P < 0.0001) and ΔCVPEE (r = 0.58; R2 = 0.34; P < 0.0001). Bland-Altman analysis of IJVP revealed a large positive bias compared to spontaneous breathing CVP (3.6 mmHg; SD = 4.0; CV = 85%; P < 0.0001) and CVPEE (3.6 mmHg; SD = 4.2; CV = 84%; P < 0.0001). Assessment of absolute IJVP via compression sonography correlated poorly with direct measurements of CVP by invasive catheterization over a range of venous pressures that are physiologically relevant to spaceflight. However, compression sonography showed modest utility for tracking changes in venous pressure over time. NEW FINDINGS: What is the central question of this study? Compression sonography has been proposed as a novel method for non-invasive measurement of venous pressures during spaceflight. However, the accuracy has not yet been confirmed in the range of CVP experienced by astronauts during spaceflight. What is the main finding and its importance? Our data show that compression sonography of the internal jugular vein correlates poorly with direct measurement of central venous pressures in a range that is physiologically relevant to spaceflight. However, compression sonography showed modest utility for tracking changes in venous pressure over time.
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Affiliation(s)
- Christopher M. Hearon
- Institute for Exercise and Environmental MedicineTexas Health Presbyterian Hospital DallasDallasTXUSA
- University of Texas Southwestern Medical CenterDallasTXUSA
| | - Kirsten Peters
- University Medical CenterRadboud UniversityNijmegenthe Netherlands
| | - Katrin A. Dias
- Institute for Exercise and Environmental MedicineTexas Health Presbyterian Hospital DallasDallasTXUSA
- University of Texas Southwestern Medical CenterDallasTXUSA
| | - James P. Macnamara
- Institute for Exercise and Environmental MedicineTexas Health Presbyterian Hospital DallasDallasTXUSA
- University of Texas Southwestern Medical CenterDallasTXUSA
| | - John E. T. Marshall
- Institute for Exercise and Environmental MedicineTexas Health Presbyterian Hospital DallasDallasTXUSA
- University of Texas Southwestern Medical CenterDallasTXUSA
| | - Joseph Campain
- Institute for Exercise and Environmental MedicineTexas Health Presbyterian Hospital DallasDallasTXUSA
- University of Texas Southwestern Medical CenterDallasTXUSA
| | | | | | - Benjamin D. Levine
- Institute for Exercise and Environmental MedicineTexas Health Presbyterian Hospital DallasDallasTXUSA
- University of Texas Southwestern Medical CenterDallasTXUSA
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Slade L, Bollen SE, Bass JJ, Phillips BE, Smith K, Wilkinson DJ, Szewczyk NJ, Atherton PJ, Etheridge T. Bisphosphonates attenuate age-related muscle decline in Caenorhabditis elegans. J Cachexia Sarcopenia Muscle 2023; 14:2613-2622. [PMID: 37722921 PMCID: PMC10751425 DOI: 10.1002/jcsm.13335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 07/17/2023] [Accepted: 08/21/2023] [Indexed: 09/20/2023] Open
Abstract
BACKGROUND Age-related muscle decline (sarcopenia) associates with numerous health risk factors and poor quality of life. Drugs that counter sarcopenia without harmful side effects are lacking, and repurposing existing pharmaceuticals could expedite realistic clinical options. Recent studies suggest bisphosphonates promote muscle health; however, the efficacy of bisphosphonates as an anti-sarcopenic therapy is currently unclear. METHODS Using Caenorhabditis elegans as a sarcopenia model, we treated animals with 100 nM, 1, 10, 100 and 500 μM zoledronic acid (ZA) and assessed lifespan and healthspan (movement rates) using a microfluidic chip device. The effects of ZA on sarcopenia were examined using GFP-tagged myofibres or mitochondria at days 0, 4 and 6 post-adulthood. Mechanisms of ZA-mediated healthspan extension were determined using combined ZA and targeted RNAi gene knockdown across the life-course. RESULTS We found 100 nM and 1 μM ZA increased lifespan (P < 0.001) and healthspan [954 ± 53 (100 nM) and 963 ± 48 (1 μM) vs. 834 ± 59% (untreated) population activity AUC, P < 0.05]. 10 μM ZA shortened lifespan (P < 0.0001) but not healthspan (758.9 ± 37 vs. 834 ± 59, P > 0.05), whereas 100 and 500 μM ZA were larval lethal. ZA (1 μM) significantly improved myofibrillar structure on days 4 and 6 post-adulthood (83 and 71% well-organized myofibres, respectively, vs. 56 and 34% controls, P < 0.0001) and increased well-networked mitochondria at day 6 (47 vs. 16% in controls, P < 0.01). Genes required for ZA-mediated healthspan extension included fdps-1/FDPS-1 (278 ± 9 vs. 894 ± 17% population activity AUC in knockdown + 1 μM ZA vs. untreated controls, respectively, P < 0.0001), daf-16/FOXO (680 ± 16 vs. 894 ± 17%, P < 0.01) and agxt-2/BAIBA (531 ± 23 vs. 552 ± 8%, P > 0.05). Life/healthspan was extended through knockdown of igdb-1/FNDC5 (635 ± 10 vs. 523 ± 10% population activity AUC in gene knockdown vs. untreated controls, P < 0.01) and sir-2.3/SIRT-4 (586 ± 10 vs. 523 ± 10%, P < 0.05), with no synergistic improvements in ZA co-treatment vs. knockdown alone [651 ± 12 vs. 635 ± 10% (igdb-1/FNDC5) and 583 ± 9 vs. 586 ± 10% (sir-2.3/SIRT-4), both P > 0.05]. Conversely, let-756/FGF21 and sir-2.2/SIRT-4 were dispensable for ZA-induced healthspan [630 ± 6 vs. 523 ± 10% population activity AUC in knockdown + 1 μM ZA vs. untreated controls, P < 0.01 (let-756/FGF21) and 568 ± 9 vs. 523 ± 10%, P < 0.05 (sir-2.2/SIRT-4)]. CONCLUSIONS Despite lacking an endoskeleton, ZA delays Caenorhabditis elegans sarcopenia, which translates to improved neuromuscular function across the life course. Bisphosphonates might, therefore, be an immediately exploitable anti-sarcopenia therapy.
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Affiliation(s)
- Luke Slade
- University of Exeter Medical SchoolExeterUK
- Faculty of Health and Life SciencesUniversity of ExeterExeterUK
| | - Shelby E. Bollen
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC‐Versus Arthritis Centre for Musculoskeletal Ageing Research (CMAR), Unit of Injury, Recovery and Inflammation Sciences (IRIS), School of MedicineUniversity of NottinghamDerbyUK
| | - Joseph J. Bass
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC‐Versus Arthritis Centre for Musculoskeletal Ageing Research (CMAR), Unit of Injury, Recovery and Inflammation Sciences (IRIS), School of MedicineUniversity of NottinghamDerbyUK
| | - Bethan E. Phillips
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC‐Versus Arthritis Centre for Musculoskeletal Ageing Research (CMAR), Unit of Injury, Recovery and Inflammation Sciences (IRIS), School of MedicineUniversity of NottinghamDerbyUK
| | - Kenneth Smith
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC‐Versus Arthritis Centre for Musculoskeletal Ageing Research (CMAR), Unit of Injury, Recovery and Inflammation Sciences (IRIS), School of MedicineUniversity of NottinghamDerbyUK
| | - Daniel J. Wilkinson
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC‐Versus Arthritis Centre for Musculoskeletal Ageing Research (CMAR), Unit of Injury, Recovery and Inflammation Sciences (IRIS), School of MedicineUniversity of NottinghamDerbyUK
| | - Nathaniel J. Szewczyk
- Ohio Musculoskeletal and Neurological InstituteHeritage College of Osteopathic MedicineAthensOHUSA
| | - Philip J. Atherton
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC‐Versus Arthritis Centre for Musculoskeletal Ageing Research (CMAR), Unit of Injury, Recovery and Inflammation Sciences (IRIS), School of MedicineUniversity of NottinghamDerbyUK
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Bloomfield KJ, Stocker BD, Keenan TF, Prentice IC. Environmental controls on the light use efficiency of terrestrial gross primary production. Glob Chang Biol 2023; 29:1037-1053. [PMID: 36334075 PMCID: PMC10099475 DOI: 10.1111/gcb.16511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 10/12/2022] [Accepted: 10/17/2022] [Indexed: 06/16/2023]
Abstract
Gross primary production (GPP) by terrestrial ecosystems is a key quantity in the global carbon cycle. The instantaneous controls of leaf-level photosynthesis are well established, but there is still no consensus on the mechanisms by which canopy-level GPP depends on spatial and temporal variation in the environment. The standard model of photosynthesis provides a robust mechanistic representation for C3 species; however, additional assumptions are required to "scale up" from leaf to canopy. As a consequence, competing models make inconsistent predictions about how GPP will respond to continuing environmental change. This problem is addressed here by means of an empirical analysis of the light use efficiency (LUE) of GPP inferred from eddy covariance carbon dioxide flux measurements, in situ measurements of photosynthetically active radiation (PAR), and remotely sensed estimates of the fraction of PAR (fAPAR) absorbed by the vegetation canopy. Focusing on LUE allows potential drivers of GPP to be separated from its overriding dependence on light. GPP data from over 100 sites, collated over 20 years and located in a range of biomes and climate zones, were extracted from the FLUXNET2015 database and combined with remotely sensed fAPAR data to estimate daily LUE. Daytime air temperature, vapor pressure deficit, diffuse fraction of solar radiation, and soil moisture were shown to be salient predictors of LUE in a generalized linear mixed-effects model. The same model design was fitted to site-based LUE estimates generated by 16 terrestrial ecosystem models. The published models showed wide variation in the shape, the strength, and even the sign of the environmental effects on modeled LUE. These findings highlight important model deficiencies and suggest a need to progress beyond simple "goodness of fit" comparisons of inferred and predicted carbon fluxes toward an approach focused on the functional responses of the underlying dependencies.
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Affiliation(s)
- Keith J. Bloomfield
- Georgina Mace Centre for the Living Planet, Department of Life Sciences, Imperial College LondonAscotUK
| | - Benjamin D. Stocker
- Department of Environmental Systems Science, ETHZurichSwitzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorfSwitzerland
- Institute of GeographyUniversity of BernBernSwitzerland
- Oeschger Centre for Climate Change ResearchUniversity of BernBernSwitzerland
| | - Trevor F. Keenan
- Department of Environmental Science, Policy and Management, UC BerkeleyBerkeleyCaliforniaUSA
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National LaboratoryBerkeleyCaliforniaUSA
| | - I. Colin Prentice
- Georgina Mace Centre for the Living Planet, Department of Life Sciences, Imperial College LondonAscotUK
- Department of Biological SciencesMacquarie UniversityNorth RydeNew South WalesAustralia
- Ministry of Education Key Laboratory for Earth System Modelling, Department of Earth System ScienceTsinghua UniversityBeijingChina
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Li F, Hao D, Zhu Q, Yuan K, Braghiere RK, He L, Luo X, Wei S, Riley WJ, Zeng Y, Chen M. Vegetation clumping modulates global photosynthesis through adjusting canopy light environment. Glob Chang Biol 2023; 29:731-746. [PMID: 36281563 PMCID: PMC10100496 DOI: 10.1111/gcb.16503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
The spatial dispersion of photoelements within a vegetation canopy, quantified by the clumping index (CI), directly regulates the within-canopy light environment and photosynthesis rate, but is not commonly implemented in terrestrial biosphere models to estimate the ecosystem carbon cycle. A few global CI products have been developed recently with remote sensing measurements, making it possible to examine the global impacts of CI. This study deployed CI in the radiative transfer scheme of the Community Land Model version 5 (CLM5) and used the revised CLM5 to quantitatively evaluate the extent to which CI can affect canopy absorbed radiation and gross primary production (GPP), and for the first time, considering the uncertainty and seasonal variation of CI with multiple remote sensing products. Compared to the results without considering the CI impact, the revised CLM5 estimated that sunlit canopy absorbed up to 9%-15% and 23%-34% less direct and diffuse radiation, respectively, while shaded canopy absorbed 3%-18% more diffuse radiation across different biome types. The CI impacts on canopy light conditions included changes in canopy light absorption, and sunlit-shaded leaf area fraction related to nitrogen distribution and thus the maximum rate of Rubisco carboxylase activity (Vcmax ), which together decreased photosynthesis in sunlit canopy by 5.9-7.2 PgC year-1 while enhanced photosynthesis by 6.9-8.2 PgC year-1 in shaded canopy. With higher light use efficiency of shaded leaves, shaded canopy increased photosynthesis compensated and exceeded the lost photosynthesis in sunlit canopy, resulting in 1.0 ± 0.12 PgC year-1 net increase in GPP. The uncertainty of GPP due to the different input CI datasets was much larger than that caused by CI seasonal variations, and was up to 50% of the magnitude of GPP interannual variations in the tropical regions. This study highlights the necessity of considering the impacts of CI and its uncertainty in terrestrial biosphere models.
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Affiliation(s)
- Fa Li
- Department of Forest and Wildlife EcologyUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
| | - Dalei Hao
- Atmospheric Sciences and Global Change DivisionPacific Northwest National LaboratoryRichlandWashingtonUSA
| | - Qing Zhu
- Climate and Ecosystem Sciences Division, Climate Sciences DepartmentLawrence Berkeley National LaboratoryBerkeleyCaliforniaUSA
| | - Kunxiaojia Yuan
- Climate and Ecosystem Sciences Division, Climate Sciences DepartmentLawrence Berkeley National LaboratoryBerkeleyCaliforniaUSA
| | - Renato K. Braghiere
- Division of Geological and Planetary SciencesCalifornia Institute of TechnologyPasadenaCaliforniaUSA
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCaliforniaUSA
| | - Liming He
- Canada Centre for Mapping and Earth ObservationNatural Resources CanadaOttawaOntarioCanada
| | - Xiangzhong Luo
- Department of GeographyNational University of SingaporeSingaporeSingapore
| | - Shanshan Wei
- Centre for Remote Imaging, Sensing and ProcessingNational University of SingaporeSingaporeSingapore
| | - William J. Riley
- Climate and Ecosystem Sciences Division, Climate Sciences DepartmentLawrence Berkeley National LaboratoryBerkeleyCaliforniaUSA
| | - Yelu Zeng
- Department of Forest and Wildlife EcologyUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
| | - Min Chen
- Department of Forest and Wildlife EcologyUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
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Mahon AR, Grey EK, Jerde CL. Integrating invasive species risk assessment into environmental DNA metabarcoding reference libraries. Ecol Appl 2023; 33:e2730. [PMID: 36054696 PMCID: PMC10078450 DOI: 10.1002/eap.2730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 05/12/2022] [Accepted: 06/22/2022] [Indexed: 06/15/2023]
Abstract
Environmental DNA (eDNA) metabarcoding has shown promise as a tool for estimating biodiversity and early detection of invasive species. In aquatic systems, advantages of this method include the ability to concurrently monitor biodiversity and detect incipient invasions simply through the collection and analysis of water samples. However, depending on the molecular markers chosen for a given study, reference libraries containing target sequences from present species may limit the usefulness of eDNA metabarcoding. To explore the extent of this issue and how it may be resolved to aid biodiversity and invasive species early detection goals, we focus on fishes in the well-studied Laurentian Great Lakes region. First, we provide a synthesis of species currently known from the region and of non-indigenous species identified as threats by international, national, regional, and introduction pathway-specific fish risk assessments. With these species lists, we then evaluate 23 primer pairs commonly used in fish eDNA metabarcoding with available databases of sequence coverage and species specificity. Finally, we identify established and potentially invasive non-indigenous fish that should be prioritized for genetic sequencing to ensure robust eDNA metabarcoding for the region. Our results should increase confidence in using eDNA metabarcoding for fisheries conservation and management in the Great Lakes region and help prioritize reference sequencing efforts. The ultimate utility of eDNA metabarcoding approaches will come when conservation management of existing fish communities is integrated with early detection efforts for invasive species surveillance to assess total fish biodiversity.
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Affiliation(s)
- Andrew R. Mahon
- Department of BiologyCentral Michigan UniversityMount PleasantMichiganUSA
| | - Erin K. Grey
- School of Biology and Ecology and Maine Center for Genetics in the EnvironmentUniversity of MaineOronoMaineUSA
| | - Christopher L. Jerde
- Marine Science InstituteUniversity of California Santa BarbaraSanta BarbaraCaliforniaUSA
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Dong N, Wright IJ, Chen JM, Luo X, Wang H, Keenan TF, Smith NG, Prentice IC. Rising CO 2 and warming reduce global canopy demand for nitrogen. New Phytol 2022; 235:1692-1700. [PMID: 35297050 PMCID: PMC9545159 DOI: 10.1111/nph.18076] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 02/25/2022] [Indexed: 05/27/2023]
Abstract
Nitrogen (N) limitation has been considered as a constraint on terrestrial carbon uptake in response to rising CO2 and climate change. By extension, it has been suggested that declining carboxylation capacity (Vcmax ) and leaf N content in enhanced-CO2 experiments and satellite records signify increasing N limitation of primary production. We predicted Vcmax using the coordination hypothesis and estimated changes in leaf-level photosynthetic N for 1982-2016 assuming proportionality with leaf-level Vcmax at 25°C. The whole-canopy photosynthetic N was derived using satellite-based leaf area index (LAI) data and an empirical extinction coefficient for Vcmax , and converted to annual N demand using estimated leaf turnover times. The predicted spatial pattern of Vcmax shares key features with an independent reconstruction from remotely sensed leaf chlorophyll content. Predicted leaf photosynthetic N declined by 0.27% yr-1 , while observed leaf (total) N declined by 0.2-0.25% yr-1 . Predicted global canopy N (and N demand) declined from 1996 onwards, despite increasing LAI. Leaf-level responses to rising CO2 , and to a lesser extent temperature, may have reduced the canopy requirement for N by more than rising LAI has increased it. This finding provides an alternative explanation for declining leaf N that does not depend on increasing N limitation.
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Affiliation(s)
- Ning Dong
- Department of Life SciencesGeorgina Mace Centre for the Living PlanetImperial College LondonSilwood Park CampusAscotSL5 7PYUK
- Department of Biological SciencesMacquarie UniversityNorth RydeNSW2109Australia
| | - Ian J. Wright
- Department of Biological SciencesMacquarie UniversityNorth RydeNSW2109Australia
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityLocked Bag 1797PenrithNSW2751Australia
| | - Jing M. Chen
- Department of Geography and PlanningUniversity of Toronto100 George StreetTorontoONMS5 3G3Canada
| | - Xiangzhong Luo
- Department of GeographyNational University of Singapore1 Arts LinkSingapore117570Singapore
| | - Han Wang
- Department of Earth System ScienceMinistry of Education Key Laboratory for Earth System ModellingInstitute for Global Change StudiesTsinghua UniversityBeijing100084China
| | - Trevor F. Keenan
- Department of Environmental Science, Policy and ManagementUC BerkeleyBerkeleyCAUSA
- Climate and Ecosystem Sciences DivisionLawrence Berkeley National LaboratoryBerkeleyCAUSA
| | - Nicholas G. Smith
- Department of Biological SciencesTexas Tech UniversityLubbockTX79409USA
| | - Iain Colin Prentice
- Department of Life SciencesGeorgina Mace Centre for the Living PlanetImperial College LondonSilwood Park CampusAscotSL5 7PYUK
- Department of Biological SciencesMacquarie UniversityNorth RydeNSW2109Australia
- Department of Earth System ScienceMinistry of Education Key Laboratory for Earth System ModellingInstitute for Global Change StudiesTsinghua UniversityBeijing100084China
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Jenouvrier S, Long MC, Coste CFD, Holland M, Gamelon M, Yoccoz NG, Sæther B. Detecting climate signals in populations across life histories. Glob Chang Biol 2022; 28:2236-2258. [PMID: 34931401 PMCID: PMC9303565 DOI: 10.1111/gcb.16041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 11/30/2021] [Accepted: 12/01/2021] [Indexed: 06/14/2023]
Abstract
Climate impacts are not always easily discerned in wild populations as detecting climate change signals in populations is challenged by stochastic noise associated with natural climate variability, variability in biotic and abiotic processes, and observation error in demographic rates. Detection of the impact of climate change on populations requires making a formal distinction between signals in the population associated with long-term climate trends from those generated by stochastic noise. The time of emergence (ToE) identifies when the signal of anthropogenic climate change can be quantitatively distinguished from natural climate variability. This concept has been applied extensively in the climate sciences, but has not been explored in the context of population dynamics. Here, we outline an approach to detecting climate-driven signals in populations based on an assessment of when climate change drives population dynamics beyond the envelope characteristic of stochastic variations in an unperturbed state. Specifically, we present a theoretical assessment of the time of emergence of climate-driven signals in population dynamics ( ToE pop ). We identify the dependence of ToE pop on the magnitude of both trends and variability in climate and also explore the effect of intrinsic demographic controls on ToE pop . We demonstrate that different life histories (fast species vs. slow species), demographic processes (survival, reproduction), and the relationships between climate and demographic rates yield population dynamics that filter climate trends and variability differently. We illustrate empirically how to detect the point in time when anthropogenic signals in populations emerge from stochastic noise for a species threatened by climate change: the emperor penguin. Finally, we propose six testable hypotheses and a road map for future research.
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Affiliation(s)
- Stéphanie Jenouvrier
- Biology DepartmentWoods Hole Oceanographic InstitutionWoods HoleMassachusettsUSA
| | | | - Christophe F. D. Coste
- Centre for Biodiversity DynamicsDepartment of BiologyNorwegian University of Science and TechnologyTrondheimNorway
| | - Marika Holland
- National Center for Atmospheric ResearchBoulderColoradoUSA
| | - Marlène Gamelon
- Centre for Biodiversity DynamicsDepartment of BiologyNorwegian University of Science and TechnologyTrondheimNorway
- Laboratoire de Biométrie et Biologie ÉvolutiveCNRSUnité Mixte de Recherche (UMR) 5558Université Lyon 1Université de LyonVilleurbanneFrance
| | - Nigel G. Yoccoz
- Department of Arctic and Marine BiologyUiT The Arctic University of NorwayTromsøNorway
| | - Bernt‐Erik Sæther
- Centre for Biodiversity DynamicsDepartment of BiologyNorwegian University of Science and TechnologyTrondheimNorway
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9
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Meunier F, Visser MD, Shiklomanov A, Dietze MC, Guzmán Q. JA, Sanchez‐Azofeifa GA, De Deurwaerder HPT, Krishna Moorthy SM, Schnitzer SA, Marvin DC, Longo M, Liu C, Broadbent EN, Almeyda Zambrano AM, Muller‐Landau HC, Detto M, Verbeeck H. Liana optical traits increase tropical forest albedo and reduce ecosystem productivity. Glob Chang Biol 2022; 28:227-244. [PMID: 34651375 PMCID: PMC9298317 DOI: 10.1111/gcb.15928] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 09/30/2021] [Accepted: 10/07/2021] [Indexed: 06/13/2023]
Abstract
Lianas are a key growth form in tropical forests. Their lack of self-supporting tissues and their vertical position on top of the canopy make them strong competitors of resources. A few pioneer studies have shown that liana optical traits differ on average from those of colocated trees. Those trait discrepancies were hypothesized to be responsible for the competitive advantage of lianas over trees. Yet, in the absence of reliable modelling tools, it is impossible to unravel their impact on the forest energy balance, light competition, and on the liana success in Neotropical forests. To bridge this gap, we performed a meta-analysis of the literature to gather all published liana leaf optical spectra, as well as all canopy spectra measured over different levels of liana infestation. We then used a Bayesian data assimilation framework applied to two radiative transfer models (RTMs) covering the leaf and canopy scales to derive tropical tree and liana trait distributions, which finally informed a full dynamic vegetation model. According to the RTMs inversion, lianas grew thinner, more horizontal leaves with lower pigment concentrations. Those traits made the lianas very efficient at light interception and significantly modified the forest energy balance and its carbon cycle. While forest albedo increased by 14% in the shortwave, light availability was reduced in the understorey (-30% of the PAR radiation) and soil temperature decreased by 0.5°C. Those liana-specific traits were also responsible for a significant reduction of tree (-19%) and ecosystem (-7%) gross primary productivity (GPP) while lianas benefited from them (their GPP increased by +27%). This study provides a novel mechanistic explanation to the increase in liana abundance, new evidence of the impact of lianas on forest functioning, and paves the way for the evaluation of the large-scale impacts of lianas on forest biogeochemical cycles.
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Affiliation(s)
- Félicien Meunier
- CAVElab—Computational and Applied Vegetation EcologyDepartment of EnvironmentGhent UniversityGhentBelgium
- Department of Earth and EnvironmentBoston UniversityBostonMassachusettsUSA
| | - Marco D. Visser
- Department of Ecology and Evolutionary BiologyPrinceton UniversityPrincetonNew JerseyUSA
- Institute of Environmental SciencesLeiden UniversityLeidenThe Netherlands
| | | | - Michael C. Dietze
- Department of Earth and EnvironmentBoston UniversityBostonMassachusettsUSA
| | - J. Antonio Guzmán Q.
- Centre for Earth Observation Sciences (CEOS)Earth and Atmospheric Sciences DepartmentUniversity of AlbertaEdmontonAlbertaCanada
| | - G. Arturo Sanchez‐Azofeifa
- Centre for Earth Observation Sciences (CEOS)Earth and Atmospheric Sciences DepartmentUniversity of AlbertaEdmontonAlbertaCanada
- Smithsonian Tropical Research InstituteBalboaPanama
| | | | - Sruthi M. Krishna Moorthy
- CAVElab—Computational and Applied Vegetation EcologyDepartment of EnvironmentGhent UniversityGhentBelgium
| | - Stefan A. Schnitzer
- Smithsonian Tropical Research InstituteBalboaPanama
- Department of Biological SciencesMarquette UniversityMilwaukeeWisconsinUSA
| | | | - Marcos Longo
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCaliforniaUSA
| | - Chang Liu
- CAVElab—Computational and Applied Vegetation EcologyDepartment of EnvironmentGhent UniversityGhentBelgium
| | - Eben N. Broadbent
- Spatial Ecology and Conservation (SPEC) Lab, School of Forest, Fisheries, and Geomatics SciencesUniversity of FloridaGainesvilleFloridaUSA
- Spatial Ecology and Conservation (SPEC) Lab, Center for Latin American StudiesUniversity of FloridaGainesvilleFloridaUSA
| | - Angelica M. Almeyda Zambrano
- Spatial Ecology and Conservation (SPEC) Lab, Center for Latin American StudiesUniversity of FloridaGainesvilleFloridaUSA
| | | | - Matteo Detto
- Department of Ecology and Evolutionary BiologyPrinceton UniversityPrincetonNew JerseyUSA
- Smithsonian Tropical Research InstituteBalboaPanama
| | - Hans Verbeeck
- CAVElab—Computational and Applied Vegetation EcologyDepartment of EnvironmentGhent UniversityGhentBelgium
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10
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Goldberg DL, Anenberg SC, Griffin D, McLinden CA, Lu Z, Streets DG. Disentangling the Impact of the COVID-19 Lockdowns on Urban NO 2 From Natural Variability. Geophys Res Lett 2020; 47:e2020GL089269. [PMID: 32904906 PMCID: PMC7461033 DOI: 10.1029/2020gl089269] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/30/2020] [Accepted: 08/03/2020] [Indexed: 05/20/2023]
Abstract
TROPOMI satellite data show substantial drops in nitrogen dioxide (NO2) during COVID-19 physical distancing. To attribute NO2 changes to NO x emissions changes over short timescales, one must account for meteorology. We find that meteorological patterns were especially favorable for low NO2 in much of the United States in spring 2020, complicating comparisons with spring 2019. Meteorological variations between years can cause column NO2 differences of ~15% over monthly timescales. After accounting for solar angle and meteorological considerations, we calculate that NO2 drops ranged between 9.2% and 43.4% among 20 cities in North America, with a median of 21.6%. Of the studied cities, largest NO2 drops (>30%) were in San Jose, Los Angeles, and Toronto, and smallest drops (<12%) were in Miami, Minneapolis, and Dallas. These normalized NO2 changes can be used to highlight locations with greater activity changes and better understand the sources contributing to adverse air quality in each city.
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Affiliation(s)
- Daniel L. Goldberg
- Department of Environmental and Occupational HealthGeorge Washington UniversityWashingtonDCUSA
- Energy Systems DivisionArgonne National LaboratoryLemontILUSA
| | - Susan C. Anenberg
- Department of Environmental and Occupational HealthGeorge Washington UniversityWashingtonDCUSA
| | - Debora Griffin
- Air Quality Research DivisionEnvironment and Climate Change Canada (ECCC)TorontoOntarioCanada
| | - Chris A. McLinden
- Air Quality Research DivisionEnvironment and Climate Change Canada (ECCC)TorontoOntarioCanada
| | - Zifeng Lu
- Energy Systems DivisionArgonne National LaboratoryLemontILUSA
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