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Xia Y, Turner BL, Li Y, Lian P, Yang Z, Fan Y, Yang L, Yang Y. Phosphorus addition enhances heterotrophic respiration but reduces root respiration in a subtropical plantation forest. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 934:173158. [PMID: 38735329 DOI: 10.1016/j.scitotenv.2024.173158] [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: 01/16/2024] [Revised: 05/09/2024] [Accepted: 05/09/2024] [Indexed: 05/14/2024]
Abstract
Soil respiration (Rs) is a major component of the global carbon (C) cycle and is influenced by the availability of nutrients such as phosphorus (P). However, the response of Rs to P addition in P-limited subtropical forest ecosystems and the underlying mechanisms remain poorly understood. To address this, we conducted a P addition experiment (50 kg P ha-1 yr-1) in a subtropical Chinese fir (Cunninghamia lanceolata) plantation forest. We separated Rs into heterotrophic respiration (Rh), root respiration (Rr), and mycorrhizal hyphal respiration (Rm), and quantified soil properties, microbial biomass (phospholipid fatty acid, PLFA), fungal community composition (ITS), and the activity of extracellular enzymes. Phosphorus addition significantly increased Rs and Rh, but decreased Rr and did not influence Rm. Further, P addition increased fungal, bacterial, and total PLFAs, and phenol oxidase activity. Conversely, P application decreased root biomass and did not alter the relative abundance of symbiotrophic fungi. Phosphorus enrichment therefore enhances soil C emissions by promoting organic matter decomposition by heterotrophic activity, rather than via increases in root or mycorrhizal respiration. This advances our mechanistic understanding of the relationship between fertility and soil respiration in subtropical forests, with implications for predicting soil C emissions under global change.
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Affiliation(s)
- Yun Xia
- School of Geographical Science, Fujian Normal University, Fuzhou 350007, China; Key Laboratory of Humid Subtropical Eco-geographical Process of Ministry of Education, Fujian Provincial Key Laboratory for Plant Eco-physiology, Fujian Normal University, Fuzhou 350117, China; Institute of Geography, Fujian Normal University, Fuzhou 350007, China
| | - Benjamin L Turner
- Institute of Agriculture and Life Sciences, Gyeongsang National University, Jinju 52828, South Korea
| | - Yiqing Li
- College of Agriculture, Forestry and Natural Resources Management, University of Hawaii, Hilo, HI 96720, USA
| | - Pingping Lian
- School of Design, Fujian University of Technology, Fuzhou 350118, China
| | - Zhijie Yang
- School of Geographical Science, Fujian Normal University, Fuzhou 350007, China; Key Laboratory of Humid Subtropical Eco-geographical Process of Ministry of Education, Fujian Provincial Key Laboratory for Plant Eco-physiology, Fujian Normal University, Fuzhou 350117, China; Institute of Geography, Fujian Normal University, Fuzhou 350007, China
| | - Yuexin Fan
- School of Geographical Science, Fujian Normal University, Fuzhou 350007, China; Key Laboratory of Humid Subtropical Eco-geographical Process of Ministry of Education, Fujian Provincial Key Laboratory for Plant Eco-physiology, Fujian Normal University, Fuzhou 350117, China; Institute of Geography, Fujian Normal University, Fuzhou 350007, China.
| | - Liuming Yang
- School of Geographical Science, Fujian Normal University, Fuzhou 350007, China; Key Laboratory of Humid Subtropical Eco-geographical Process of Ministry of Education, Fujian Provincial Key Laboratory for Plant Eco-physiology, Fujian Normal University, Fuzhou 350117, China; Institute of Geography, Fujian Normal University, Fuzhou 350007, China.
| | - Yusheng Yang
- School of Geographical Science, Fujian Normal University, Fuzhou 350007, China; Key Laboratory of Humid Subtropical Eco-geographical Process of Ministry of Education, Fujian Provincial Key Laboratory for Plant Eco-physiology, Fujian Normal University, Fuzhou 350117, China; Institute of Geography, Fujian Normal University, Fuzhou 350007, China
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Zhao J, Hu Y, Wang J, Gao W, Liu D, Yang M, Chen X, Xie H, He H, Zhang X, Lu C. Greenhouse gas emissions from the growing season are regulated by precipitation events in conservation tillage farmland ecosystems of Northeast China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 948:174716. [PMID: 39004355 DOI: 10.1016/j.scitotenv.2024.174716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 07/08/2024] [Accepted: 07/09/2024] [Indexed: 07/16/2024]
Abstract
Reducing greenhouse gas (GHG) emissions from agricultural ecosystems is vital to mitigate global warming. Conservation tillage is widely used in farmland management to improve soil quality; however, its effects on soil GHG emissions remain poorly understood, particularly in high-yield areas. Therefore, our study aimed to evaluate the effects of no-tillage (NT) combined with four straw-mulching levels (0 %, 33 %, 67 %, and 100 %) on GHG emission risk and the main influencing factors. We conducted in-situ observations of GHG emissions from soils under different management practices during the maize-growing season in Northeastern China. The results showed that NT0 (705.94 g m-2) reduced CO2 emissions by 18 % compared to ridge tillage (RT, 837.04 g m-2). Different straw mulching levels stimulated N2O emissions after rainfall, particularly under NT combined with 100 % straw mulching (2.89 kg ha-1), which was 45 % higher than that in any other treatments. The CH4 emissions flux among different treatments was nearly zero. Overall, straw mulching levels had no significant effect on the GHG emissions. During the growing season, soil NH4+-N (< 20 mg kg-1) remained low and decreased with the extension of growth stage, whereas soil NO3--N initially increased and then decreased. More importantly, the results of structural equation modeling indicate that: a) organic material input and soil moisture are key factors affecting CO2 emissions, b) nitrogen fertilizer and soil moisture promote N2O emissions, and c) climatic factors exert an inexorable influence on the GHG emissions process. Our conclusions emphasize the necessity of incorporating precipitation-response measures into farmland management to reduce the risk of GHG emissions.
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Affiliation(s)
- Jinxi Zhao
- Key Laboratory of Pollution Ecology and Environment Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Yanyu Hu
- Key Laboratory of Pollution Ecology and Environment Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Jing Wang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, 210037, China
| | - Wanjing Gao
- Key Laboratory of Pollution Ecology and Environment Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Deyao Liu
- School of Agriculture, Food and Ecosystem Sciences, Faculty of Science, The University of Melbourne, VIC 3010, Australia
| | - Miaoyin Yang
- Key Laboratory of Pollution Ecology and Environment Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Xin Chen
- Key Laboratory of Pollution Ecology and Environment Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Hongtu Xie
- Key Laboratory of Conservation Tillage and Ecological Agriculture, Liaoning 110016, China
| | - Hongbo He
- Key Laboratory of Conservation Tillage and Ecological Agriculture, Liaoning 110016, China
| | - Xudong Zhang
- Key Laboratory of Conservation Tillage and Ecological Agriculture, Liaoning 110016, China
| | - Caiyan Lu
- Key Laboratory of Pollution Ecology and Environment Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Key Laboratory of Terrestrial Ecosystem Carbon Neutrality, Liaoning 110016, China.
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Gutiérrez-Cánovas C, von Schiller D, Pace G, Gómez-Gener L, Pascoal C. Multiple stressors alter greenhouse gas concentrations in streams through local and distal processes. GLOBAL CHANGE BIOLOGY 2024; 30:e17301. [PMID: 38687496 DOI: 10.1111/gcb.17301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 03/14/2024] [Accepted: 03/23/2024] [Indexed: 05/02/2024]
Abstract
Streams are significant contributors of greenhouse gases (GHG) to the atmosphere, and the increasing number of stressors degrading freshwaters may exacerbate this process, posing a threat to climatic stability. However, it is unclear whether the influence of multiple stressors on GHG concentrations in streams results from increases of in-situ metabolism (i.e., local processes) or from changes in upstream and terrestrial GHG production (i.e., distal processes). Here, we hypothesize that the mechanisms controlling multiple stressor effects vary between carbon dioxide (CO2) and methane (CH4), with the latter being more influenced by changes in local stream metabolism, and the former mainly responding to distal processes. To test this hypothesis, we measured stream metabolism and the concentrations of CO2 (pCO2) and CH4 (pCH4) in 50 stream sites that encompass gradients of nutrient enrichment, oxygen depletion, thermal stress, riparian degradation and discharge. Our results indicate that these stressors had additive effects on stream metabolism and GHG concentrations, with stressor interactions explaining limited variance. Nutrient enrichment was associated with higher stream heterotrophy and pCO2, whereas pCH4 increased with oxygen depletion and water temperature. Discharge was positively linked to primary production, respiration and heterotrophy but correlated negatively with pCO2. Our models indicate that CO2-equivalent concentrations can more than double in streams that experience high nutrient enrichment and oxygen depletion, compared to those with oligotrophic and oxic conditions. Structural equation models revealed that the effects of nutrient enrichment and discharge on pCO2 were related to distal processes rather than local metabolism. In contrast, pCH4 responses to nutrient enrichment, discharge and temperature were related to both local metabolism and distal processes. Collectively, our study illustrates potential climatic feedbacks resulting from freshwater degradation and provides insight into the processes mediating stressor impacts on the production of GHG in streams.
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Affiliation(s)
| | - Daniel von Schiller
- Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals (BEECA), Universitat de Barcelona (UB), Barcelona, Spain
- Institut de Recerca de l'Aigua (IdRA), Universitat de Barcelona (UB), Barcelona, Spain
| | - Giorgio Pace
- Centre of Molecular and Environmental Biology (CBMA) / Aquatic Research Network (ARNET), Department of Biology, University of Minho, Braga, Portugal
- Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, Braga, Portugal
| | - Lluís Gómez-Gener
- Centre for Research on Ecology and Forestry Applications, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Cláudia Pascoal
- Centre of Molecular and Environmental Biology (CBMA) / Aquatic Research Network (ARNET), Department of Biology, University of Minho, Braga, Portugal
- Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, Braga, Portugal
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Zhou L, Liu Y, Men M, Peng Z, Peng Y. Widespread cooling of topsoil under nitrogen enrichment and implication for soil carbon flux. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169480. [PMID: 38123100 DOI: 10.1016/j.scitotenv.2023.169480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/25/2023] [Accepted: 12/16/2023] [Indexed: 12/23/2023]
Abstract
Increasing reactive nitrogen (N) to terrestrial ecosystems is considered to enhance ecosystem carbon sink, which plays a critical role in ameliorating global warming. Besides this indirect buffering of temperature rise, the N-induced enhancement of vegetation growth may exert a biophysical cooling effect on soils. However, the magnitude and drivers of this cooling effect have rarely been evaluated. Here, using a global meta-analysis with 321 paired measurements, we demonstrated a widespread topsoil cooling (-0.30 °C in average) under anthropogenic N enrichment, which was primarily associated with the increase in aboveground biomass. This biophysical cooling could also buffer topsoil temperature rise by an average of 0.39 °C under experimental warming. Further, the reduced soil temperature was found to contribute to a reduction of soil respiration rate as temperature declines gradually. Overall, our results underpin a previously overlooked function of global N enrichment-the lowering of topsoil temperature, which suggests that the warming of topsoil may not be as fast as previously predicted under future global change scenarios. This biophysical cooling effect will also slow down soil carbon emissions and further mitigate climate warming.
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Affiliation(s)
- Lina Zhou
- College of Resources and Environmental Sciences/Key Laboratory of Farmland Eco-Environment of Hebei, Hebei Agricultural University, Baoding 071000, China; State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; China National Botanical Garden, Beijing 100093, China; College of Geography and Tourism, Baoding University, Baoding 071000, China
| | - Yang Liu
- College of Resources and Environmental Sciences/Key Laboratory of Farmland Eco-Environment of Hebei, Hebei Agricultural University, Baoding 071000, China; State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; China National Botanical Garden, Beijing 100093, China
| | - Mingxin Men
- College of Resources and Environmental Sciences/Key Laboratory of Farmland Eco-Environment of Hebei, Hebei Agricultural University, Baoding 071000, China
| | - Zhengping Peng
- College of Resources and Environmental Sciences/Key Laboratory of Farmland Eco-Environment of Hebei, Hebei Agricultural University, Baoding 071000, China
| | - Yunfeng Peng
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; China National Botanical Garden, Beijing 100093, China.
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