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Liberati D, Guidolotti G, de Dato G, De Angelis P. Enhancement of ecosystem carbon uptake in a dry shrubland under moderate warming: The role of nitrogen-driven changes in plant morphology. GLOBAL CHANGE BIOLOGY 2021; 27:5629-5642. [PMID: 34363286 PMCID: PMC9290483 DOI: 10.1111/gcb.15823] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/07/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
Net ecosystem CO2 exchange is the result of net carbon uptake by plant photosynthesis and carbon loss by soil and plant respiration. Temperature increases due to climate change can modify the equilibrium between these fluxes and trigger ecosystem-climate feedbacks that can accelerate climate warming. As these dynamics have not been well studied in dry shrublands, we subjected a Mediterranean shrubland to a 10-year night-time temperature manipulation experiment that analyzed ecosystem carbon fluxes associated with dominant shrub species, together with several plant parameters related to leaf photosynthesis, leaf morphology, and canopy structure. Under moderate night-time warming (+0.9°C minimum daily temperature, no significant reduction in soil moisture), Cistus monspeliensis formed shoots with more leaves that were relatively larger and denser canopies that supported higher plant-level photosynthesis rates. Given that ecosystem respiration was not affected, this change in canopy morphology led to a significant enhancement in net ecosystem exchange (+47% at midday). The observed changes in shoot and canopy morphology were attributed to the improved nutritional state of the warmed plants, primarily due to changes in nitrogen cycling and higher nitrogen resorption efficiency in senescent leaves. Our results show that modifications in plant morphology triggered by moderate warming affected ecosystem CO2 fluxes, providing the first evidence for enhanced daytime carbon uptake in a dry shrubland ecosystem under experimental warming.
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Affiliation(s)
- Dario Liberati
- Department for Innovation in Biological, Agro‐Food and Forest Systems (DIBAF)University of TusciaViterboItaly
| | - Gabriele Guidolotti
- Department for Innovation in Biological, Agro‐Food and Forest Systems (DIBAF)University of TusciaViterboItaly
- Present address:
Institute of Research on Terrestrial Ecosystems (IRET)National Research Council (CNR)PoranoTRItaly
| | - Giovanbattista de Dato
- Department for Innovation in Biological, Agro‐Food and Forest Systems (DIBAF)University of TusciaViterboItaly
- Present address:
Council for Agricultural Research and Economics (CREA) – Research Centre for Forestry and WoodArezzoItaly
| | - Paolo De Angelis
- Department for Innovation in Biological, Agro‐Food and Forest Systems (DIBAF)University of TusciaViterboItaly
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Morton PA, Heinemeyer A. Vegetation matters: Correcting chamber carbon flux measurements using plant volumes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 639:769-772. [PMID: 29803047 DOI: 10.1016/j.scitotenv.2018.05.192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 05/14/2018] [Accepted: 05/15/2018] [Indexed: 06/08/2023]
Abstract
Chamber carbon flux measurements are routinely used to assess ecosystem carbon sink/source dynamics. Often these point measurements enclose considerable vegetation biomass, with fluxes upscaled in space and time for each vegetation type. Here we assess the importance of including the volume of peatland dwarf shrub vegetation in chamber flux calculations and outline a simple but effective method of assessing plant volumes. We show that inclusion of plant volumes significantly affects fluxes and that this effect becomes greater as the proportion of chamber volume occupied by plants increases. Moreover, we demonstrate that, with an initial destructive laboratory assessment for each plant species and a little practice at volume estimation, plant volumes can be accurately assessed non-destructively in the field.
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Affiliation(s)
- Phoebe A Morton
- Stockholm Environment Institute, Environment Department, University of York, YO10 5NG, UK
| | - Andreas Heinemeyer
- Stockholm Environment Institute, Environment Department, University of York, YO10 5NG, UK.
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Mauritz M, Bracho R, Celis G, Hutchings J, Natali SM, Pegoraro E, Salmon VG, Schädel C, Webb EE, Schuur EAG. Nonlinear CO 2 flux response to 7 years of experimentally induced permafrost thaw. GLOBAL CHANGE BIOLOGY 2017; 23:3646-3666. [PMID: 28208232 DOI: 10.1111/gcb.13661] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 01/19/2017] [Indexed: 06/06/2023]
Abstract
Rapid Arctic warming is expected to increase global greenhouse gas concentrations as permafrost thaw exposes immense stores of frozen carbon (C) to microbial decomposition. Permafrost thaw also stimulates plant growth, which could offset C loss. Using data from 7 years of experimental Air and Soil warming in moist acidic tundra, we show that Soil warming had a much stronger effect on CO2 flux than Air warming. Soil warming caused rapid permafrost thaw and increased ecosystem respiration (Reco ), gross primary productivity (GPP), and net summer CO2 storage (NEE). Over 7 years Reco , GPP, and NEE also increased in Control (i.e., ambient plots), but this change could be explained by slow thaw in Control areas. In the initial stages of thaw, Reco , GPP, and NEE increased linearly with thaw across all treatments, despite different rates of thaw. As thaw in Soil warming continued to increase linearly, ground surface subsidence created saturated microsites and suppressed Reco , GPP, and NEE. However Reco and GPP remained high in areas with large Eriophorum vaginatum biomass. In general NEE increased with thaw, but was more strongly correlated with plant biomass than thaw, indicating that higher Reco in deeply thawed areas during summer months was balanced by GPP. Summer CO2 flux across treatments fit a single quadratic relationship that captured the functional response of CO2 flux to thaw, water table depth, and plant biomass. These results demonstrate the importance of indirect thaw effects on CO2 flux: plant growth and water table dynamics. Nonsummer Reco models estimated that the area was an annual CO2 source during all years of observation. Nonsummer CO2 loss in warmer, more deeply thawed soils exceeded the increases in summer GPP, and thawed tundra was a net annual CO2 source.
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Affiliation(s)
- Marguerite Mauritz
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Rosvel Bracho
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL, USA
| | - Gerardo Celis
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Jack Hutchings
- Department of Geological Sciences, University of Florida, Gainesville, FL, USA
| | | | - Elaine Pegoraro
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Verity G Salmon
- Environmental Sciences Division and Climate Change Sciences Institute, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Christina Schädel
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Elizabeth E Webb
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Edward A G Schuur
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
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Chen J, Luo Y, Xia J, Wilcox KR, Cao J, Zhou X, Jiang L, Niu S, Estera KY, Huang R, Wu F, Hu T, Liang J, Shi Z, Guo J, Wang RW. Warming Effects on Ecosystem Carbon Fluxes Are Modulated by Plant Functional Types. Ecosystems 2016. [DOI: 10.1007/s10021-016-0035-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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