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Nair R, Luo Y, El-Madany T, Rolo V, Pacheco-Labrador J, Caldararu S, Morris KA, Schrumpf M, Carrara A, Moreno G, Reichstein M, Migliavacca M. Nitrogen availability and summer drought, but not N:P imbalance, drive carbon use efficiency of a Mediterranean tree-grass ecosystem. GLOBAL CHANGE BIOLOGY 2024; 30:e17486. [PMID: 39215546 DOI: 10.1111/gcb.17486] [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: 10/19/2023] [Revised: 07/03/2024] [Accepted: 07/11/2024] [Indexed: 09/04/2024]
Abstract
All ecosystems contain both sources and sinks for atmospheric carbon (C). A change in their balance of net and gross ecosystem carbon uptake, ecosystem-scale carbon use efficiency (CUEECO), is a change in their ability to buffer climate change. However, anthropogenic nitrogen (N) deposition is increasing N availability, potentially shifting terrestrial ecosystem stoichiometry towards phosphorus (P) limitation. Depending on how gross primary production (GPP, plants alone) and ecosystem respiration (RECO, plants and heterotrophs) are limited by N, P or associated changes in other biogeochemical cycles, CUEECO may change. Seasonally, CUEECO also varies as the multiple processes that control GPP and respiration and their limitations shift in time. We worked in a Mediterranean tree-grass ecosystem (locally called 'dehesa') characterized by mild, wet winters and summer droughts. We examined CUEECO from eddy covariance fluxes over 6 years under control, +N and + NP fertilized treatments on three timescales: annual, seasonal (determined by vegetation phenological phases) and 14-day aggregations. Finer aggregation allowed consideration of responses to specific patterns in vegetation activity and meteorological conditions. We predicted that CUEECO should be increased by wetter conditions, and successively by N and NP fertilization. Milder and wetter years with proportionally longer growing seasons increased CUEECO, as did N fertilization, regardless of whether P was added. Using a generalized additive model, whole ecosystem phenological status and water deficit indicators, which both varied with treatment, were the main determinants of 14-day differences in CUEECO. The direction of water effects depended on the timescale considered and occurred alongside treatment-dependent water depletion. Overall, future regional trends of longer dry summers may push these systems towards lower CUEECO.
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Affiliation(s)
- Richard Nair
- Discipline of Botany, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Yunpeng Luo
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Tarek El-Madany
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Victor Rolo
- Forest Research Group, INDEHESA, University of Extremadura, Plasencia, Cáceres, Spain
| | - Javier Pacheco-Labrador
- Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park, Maryland, USA
- Environmental Remote Sensing and Spectroscopy Laboratory (SpecLab), Spanish National Research Council, Madrid, Spain
| | - Silvia Caldararu
- Discipline of Botany, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Kendalynn A Morris
- Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park, Maryland, USA
| | - Marion Schrumpf
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
- Department of Biogeochemical Processes, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Arnaud Carrara
- Fundación Centro de Estudios Ambientales del Mediterráneo (CEAM), Valencia, Spain
| | - Gerardo Moreno
- Forest Research Group, INDEHESA, University of Extremadura, Plasencia, Cáceres, Spain
| | - Markus Reichstein
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Mirco Migliavacca
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
- European Commission Joint Research Centre, Ispra, VA, Italy
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Luo Y, El-Madany T, Ma X, Nair R, Jung M, Weber U, Filippa G, Bucher SF, Moreno G, Cremonese E, Carrara A, Gonzalez-Cascon R, Cáceres Escudero Y, Galvagno M, Pacheco-Labrador J, Martín MP, Perez-Priego O, Reichstein M, Richardson AD, Menzel A, Römermann C, Migliavacca M. Nutrients and water availability constrain the seasonality of vegetation activity in a Mediterranean ecosystem. GLOBAL CHANGE BIOLOGY 2020; 26:4379-4400. [PMID: 32348631 DOI: 10.1111/gcb.15138] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 04/16/2020] [Indexed: 06/11/2023]
Abstract
Anthropogenic nitrogen (N) deposition and resulting differences in ecosystem N and phosphorus (P) ratios are expected to impact photosynthetic capacity, that is, maximum gross primary productivity (GPPmax ). However, the interplay between N and P availability with other critical resources on seasonal dynamics of ecosystem productivity remains largely unknown. In a Mediterranean tree-grass ecosystem, we established three landscape-level (24 ha) nutrient addition treatments: N addition (NT), N and P addition (NPT), and a control site (CT). We analyzed the response of ecosystem to altered nutrient stoichiometry using eddy covariance fluxes measurements, satellite observations, and digital repeat photography. A set of metrics, including phenological transition dates (PTDs; timing of green-up and dry-down), slopes during green-up and dry-down period, and seasonal amplitude, were extracted from time series of GPPmax and used to represent the seasonality of vegetation activity. The seasonal amplitude of GPPmax was higher for NT and NPT than CT, which was attributed to changes in structure and physiology induced by fertilization. PTDs were mainly driven by rainfall and exhibited no significant differences among treatments during the green-up period. Yet, both fertilized sites senesced earlier during the dry-down period (17-19 days), which was more pronounced in the NT due to larger evapotranspiration and water usage. Fertilization also resulted in a faster increase in GPPmax during the green-up period and a sharper decline in GPPmax during the dry-down period, with less prominent decline response in NPT. Overall, we demonstrated seasonality of vegetation activity was altered after fertilization and the importance of nutrient-water interaction in such water-limited ecosystems. With the projected warming-drying trend, the positive effects of N fertilization induced by N deposition on GPPmax may be counteracted by an earlier and faster dry-down in particular in areas where the N:P ratio increases, with potential impact on the carbon cycle of water-limited ecosystems.
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Affiliation(s)
- Yunpeng Luo
- Department for Biogeochemical Integration, Max-Planck-Institute for Biogeochemistry, Jena, Germany
| | - Tarek El-Madany
- Department for Biogeochemical Integration, Max-Planck-Institute for Biogeochemistry, Jena, Germany
| | - Xuanlong Ma
- Department for Biogeochemical Integration, Max-Planck-Institute for Biogeochemistry, Jena, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
| | - Richard Nair
- Department for Biogeochemical Integration, Max-Planck-Institute for Biogeochemistry, Jena, Germany
| | - Martin Jung
- Department for Biogeochemical Integration, Max-Planck-Institute for Biogeochemistry, Jena, Germany
| | - Ulrich Weber
- Department for Biogeochemical Integration, Max-Planck-Institute for Biogeochemistry, Jena, Germany
| | - Gianluca Filippa
- Environmental Protection Agency of Aosta Valley, ARPA Valle d'Aosta, Aosta, Italy
| | - Solveig F Bucher
- Plant Biodiversity Group, Institute of Ecology and Evolution, Friedrich Schiller University Jena, Jena, Germany
- Michael-Stifel-Center Jena for Data-Driven and Simulation Science, Jena, Germany
| | - Gerardo Moreno
- Institute for Dehesa Research, University of Extremadura, Plasencia, Spain
| | - Edoardo Cremonese
- Environmental Protection Agency of Aosta Valley, ARPA Valle d'Aosta, Aosta, Italy
| | - Arnaud Carrara
- Fundación Centro de Estudios Ambientales del Mediterráneo (CEAM), Paterna, Spain
| | - Rosario Gonzalez-Cascon
- Department of Environment, National Institute for Agriculture and Food Research and Technology (INIA), Madrid, Spain
| | | | - Marta Galvagno
- Environmental Protection Agency of Aosta Valley, ARPA Valle d'Aosta, Aosta, Italy
| | - Javier Pacheco-Labrador
- Department for Biogeochemical Integration, Max-Planck-Institute for Biogeochemistry, Jena, Germany
| | - M Pilar Martín
- Environmental Remote Sensing and Spectroscopy Laboratory (SpecLab), Institute of Economic, Geography and Demography (IEGD-CCHS), Spanish National Research Council (CSIC), Madrid, Spain
| | - Oscar Perez-Priego
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, Australia
| | - Markus Reichstein
- Department for Biogeochemical Integration, Max-Planck-Institute for Biogeochemistry, Jena, Germany
- Michael-Stifel-Center Jena for Data-Driven and Simulation Science, Jena, Germany
| | - Andrew D Richardson
- School of Informatics, Computing and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | - Annette Menzel
- Department of Ecology and Ecosystem Management, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Christine Römermann
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
- Plant Biodiversity Group, Institute of Ecology and Evolution, Friedrich Schiller University Jena, Jena, Germany
- Michael-Stifel-Center Jena for Data-Driven and Simulation Science, Jena, Germany
| | - Mirco Migliavacca
- Department for Biogeochemical Integration, Max-Planck-Institute for Biogeochemistry, Jena, Germany
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