1
|
Yu Y, Zhou Y, Janssens IA, Deng Y, He X, Liu L, Yi Y, Xiao N, Wang X, Li C, Xiao C. Divergent rhizosphere and non-rhizosphere soil microbial structure and function in long-term warmed steppe due to altered root exudation. Glob Chang Biol 2024; 30:e17111. [PMID: 38273581 DOI: 10.1111/gcb.17111] [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] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 11/12/2023] [Accepted: 12/01/2023] [Indexed: 01/27/2024]
Abstract
While there is an extensive body of research on the influence of climate warming on total soil microbial communities, our understanding of how rhizosphere and non-rhizosphere soil microorganisms respond to warming remains limited. To address this knowledge gap, we investigated the impact of 4 years of soil warming on the diversity and composition of microbial communities in the rhizosphere and non-rhizosphere soil of a temperate steppe, focusing on changes in root exudation rates and exudate compositions. We used open top chambers to simulate warming conditions, resulting in an average soil temperature increase of 1.1°C over a span of 4 years. Our results showed that, in the non-rhizosphere soil, warming had no significant impact on dissolved organic carbon concentrations, compositions, or the abundance of soil microbial functional genes related to carbon and nitrogen cycling. Moreover, soil microbial diversity and community composition remained largely unaffected, although warming resulted in increased complexity of soil bacteria and fungi in the non-rhizosphere soil. In contrast, warming resulted in a substantial decrease in root exudate carbon (by 19%) and nitrogen (by 12%) concentrations and induced changes in root exudate compositions, primarily characterized by a reduction in the abundance in alcohols, coenzymes and vitamins, and phenylpropanoids and polyketides. These changes in root exudation rates and exudate compositions resulted in significant shifts in rhizosphere soil microbial diversity and community composition, ultimately leading to a reduction in the complexity of rhizosphere bacterial and fungal community networks. Altered root exudation and rhizosphere microbial community composition therefore decreased the expression of functional genes related to soil carbon and nitrogen cycling. Interestingly, we found that changes in soil carbon-related genes were primarily driven by the fungal communities and their responses to warming, both in the rhizosphere and non-rhizosphere soil. The study of soil microbial structure and function in rhizosphere and non-rhizosphere soil provides an ideal setting for understanding mechanisms for governing rhizosphere and non-rhizosphere soil carbon and nitrogen cycles. Our results highlight the distinctly varied responses of soil microorganisms in the rhizosphere and non-rhizosphere soil to climate warming. This suggests the need for models to address these processes individually, enabling more accurate predictions of the impacts of climate change on terrestrial carbon cycling.
Collapse
Affiliation(s)
- Yang Yu
- Key Laboratory of Ecology and Environment in Minority Areas (Minzu University of China), National Ethnic Affairs Commission, Beijing, China
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Yong Zhou
- Department of Wildland Resources, Utah State University, Logan, Utah, USA
- Ecology Center, Utah State University, Logan, Utah, USA
| | - Ivan A Janssens
- Research Group of Plant and Vegetation Ecology, Department of Biology, University of Antwerp, Wilrijk, Belgium
| | - Ye Deng
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Xiaojia He
- The Administrative Center for China's Agenda 21, Beijing, China
| | - Lingli Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Yin Yi
- School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Nengwen Xiao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Xiaodong Wang
- Key Laboratory of Ecology and Environment in Minority Areas (Minzu University of China), National Ethnic Affairs Commission, Beijing, China
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Chao Li
- Key Laboratory of Ecology and Environment in Minority Areas (Minzu University of China), National Ethnic Affairs Commission, Beijing, China
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Chunwang Xiao
- Key Laboratory of Ecology and Environment in Minority Areas (Minzu University of China), National Ethnic Affairs Commission, Beijing, China
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| |
Collapse
|
2
|
Cui Y, Peng S, Delgado-Baquerizo M, Rillig MC, Terrer C, Zhu B, Jing X, Chen J, Li J, Feng J, He Y, Fang L, Moorhead DL, Sinsabaugh RL, Peñuelas J. Microbial communities in terrestrial surface soils are not widely limited by carbon. Glob Chang Biol 2023; 29:4412-4429. [PMID: 37277945 DOI: 10.1111/gcb.16765] [Citation(s) in RCA: 1] [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: 10/07/2022] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 06/07/2023]
Abstract
Microbial communities in soils are generally considered to be limited by carbon (C), which could be a crucial control for basic soil functions and responses of microbial heterotrophic metabolism to climate change. However, global soil microbial C limitation (MCL) has rarely been estimated and is poorly understood. Here, we predicted MCL, defined as limited availability of substrate C relative to nitrogen and/or phosphorus to meet microbial metabolic requirements, based on the thresholds of extracellular enzyme activity across 847 sites (2476 observations) representing global natural ecosystems. Results showed that only about 22% of global sites in terrestrial surface soils show relative C limitation in microbial community. This finding challenges the conventional hypothesis of ubiquitous C limitation for soil microbial metabolism. The limited geographic extent of C limitation in our study was mainly attributed to plant litter, rather than soil organic matter that has been processed by microbes, serving as the dominant C source for microbial acquisition. We also identified a significant latitudinal pattern of predicted MCL with larger C limitation at mid- to high latitudes, whereas this limitation was generally absent in the tropics. Moreover, MCL significantly constrained the rates of soil heterotrophic respiration, suggesting a potentially larger relative increase in respiration at mid- to high latitudes than low latitudes, if climate change increases primary productivity that alleviates MCL at higher latitudes. Our study provides the first global estimates of MCL, advancing our understanding of terrestrial C cycling and microbial metabolic feedback under global climate change.
Collapse
Affiliation(s)
- Yongxing Cui
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Shushi Peng
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Manuel Delgado-Baquerizo
- Laboratorio de Biodiversidad y Funcionamiento Ecosistémico, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, Sevilla, Spain
- Unidad Asociada CSIC-UPO (BioFun). Universidad Pablo de Olavide, Sevilla, Spain
| | | | - César Terrer
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Boston, Massachusetts, USA
| | - Biao Zhu
- Institute of Ecology, College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
| | - Xin Jing
- State Key Laboratory of Grassland Agro-Ecosystems, and College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, Gansu, China
| | - Ji Chen
- Department of Agroecology, Aarhus University, Tjele, Denmark
| | - Jinquan Li
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Institute of Biodiversity Science and Institute of Eco-Chongming, School of Life Sciences, Fudan University, Shanghai, China
| | - Jiao Feng
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, China
| | - Yue He
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Linchuan Fang
- School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan, China
| | - Daryl L Moorhead
- Department of Environmental Sciences, University of Toledo, Toledo, Ohio, USA
| | - Robert L Sinsabaugh
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Josep Peñuelas
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, Catalonia, Spain
- CREAF, Cerdanyola del Vallès, Catalonia, Spain
| |
Collapse
|
3
|
Domeignoz-Horta LA, Pold G, Erb H, Sebag D, Verrecchia E, Northen T, Louie K, Eloe-Fadrosh E, Pennacchio C, Knorr MA, Frey SD, Melillo JM, DeAngelis KM. Substrate availability and not thermal acclimation controls microbial temperature sensitivity response to long-term warming. Glob Chang Biol 2023; 29:1574-1590. [PMID: 36448874 DOI: 10.1111/gcb.16544] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [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: 08/12/2022] [Accepted: 11/18/2022] [Indexed: 05/28/2023]
Abstract
Microbes are responsible for cycling carbon (C) through soils, and predicted changes in soil C stocks under climate change are highly sensitive to shifts in the mechanisms assumed to control the microbial physiological response to warming. Two mechanisms have been suggested to explain the long-term warming impact on microbial physiology: microbial thermal acclimation and changes in the quantity and quality of substrates available for microbial metabolism. Yet studies disentangling these two mechanisms are lacking. To resolve the drivers of changes in microbial physiology in response to long-term warming, we sampled soils from 13- and 28-year-old soil warming experiments in different seasons. We performed short-term laboratory incubations across a range of temperatures to measure the relationships between temperature sensitivity of physiology (growth, respiration, carbon use efficiency, and extracellular enzyme activity) and the chemical composition of soil organic matter. We observed apparent thermal acclimation of microbial respiration, but only in summer, when warming had exacerbated the seasonally-induced, already small dissolved organic matter pools. Irrespective of warming, greater quantity and quality of soil carbon increased the extracellular enzymatic pool and its temperature sensitivity. We propose that fresh litter input into the system seasonally cancels apparent thermal acclimation of C-cycling processes to decadal warming. Our findings reveal that long-term warming has indirectly affected microbial physiology via reduced C availability in this system, implying that earth system models including these negative feedbacks may be best suited to describe long-term warming effects on these soils.
Collapse
Affiliation(s)
- Luiz A Domeignoz-Horta
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Grace Pold
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Hailey Erb
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - David Sebag
- IFP Energies Nouvelles, Rueil-Malmaison, France
- Faculty of Geosciences and the Environment, Institute of Earth Surface Dynamics, University of Lausanne, Lausanne, Switzerland
| | - Eric Verrecchia
- Faculty of Geosciences and the Environment, Institute of Earth Surface Dynamics, University of Lausanne, Lausanne, Switzerland
| | - Trent Northen
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- The DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Katherine Louie
- The DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Emiley Eloe-Fadrosh
- The DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Christa Pennacchio
- The DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Melissa A Knorr
- School of Natural Resources and the Environment, University of New Hampshire, Durham, New Hampshire, USA
| | - Serita D Frey
- School of Natural Resources and the Environment, University of New Hampshire, Durham, New Hampshire, USA
| | - Jerry M Melillo
- The Ecosystems Center, Marine Biological Laboratories, Woods Hole, Massachusetts, USA
| | - Kristen M DeAngelis
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
| |
Collapse
|
4
|
Liao H, Hao X, Qin F, Delgado-Baquerizo M, Liu Y, Zhou J, Cai P, Chen W, Huang Q. Microbial autotrophy explains large-scale soil CO 2 fixation. Glob Chang Biol 2023; 29:231-242. [PMID: 36226978 DOI: 10.1111/gcb.16452] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 09/02/2022] [Indexed: 06/16/2023]
Abstract
Microbial communities play critical roles in fixing carbon from the atmosphere and fixing it in the soils. However, the large-scale variations and drivers of these microbial communities remain poorly understood. Here, we conducted a large-scale survey across China and found that soil autotrophic organisms are critical for explaining CO2 fluxes from the atmosphere to soils. In particular, we showed that large-scale variations in CO2 fixation rates are highly correlated to those in autotrophic bacteria and phototrophic protists. Paddy soils, supporting a larger proportion of obligate bacterial and protist autotrophs, display four-fold of CO2 fixation rates over upland and forest soils. Precipitation and pH, together with key ecological clusters of autotrophic microbes, also played important roles in controlling CO2 fixation. Our work provides a novel quantification on the contribution of terrestrial autotrophic microbes to soil CO2 fixation processes at a large scale, with implications for global carbon regulation under climate change.
Collapse
Affiliation(s)
- Hao Liao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Hubei Key Laboratory of Soil Environment and Pollution Remediation, Huazhong Agricultural University, Wuhan, China
| | - Xiuli Hao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Hubei Key Laboratory of Soil Environment and Pollution Remediation, Huazhong Agricultural University, Wuhan, China
| | - Fei Qin
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Hubei Key Laboratory of Soil Environment and Pollution Remediation, Huazhong Agricultural University, Wuhan, China
| | | | - Yurong Liu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Hubei Key Laboratory of Soil Environment and Pollution Remediation, Huazhong Agricultural University, Wuhan, China
| | - Jizhong Zhou
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, USA
- School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, Oklahoma, USA
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Peng Cai
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Hubei Key Laboratory of Soil Environment and Pollution Remediation, Huazhong Agricultural University, Wuhan, China
| | - Wenli Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
| | - Qiaoyun Huang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China
- Hubei Key Laboratory of Soil Environment and Pollution Remediation, Huazhong Agricultural University, Wuhan, China
| |
Collapse
|
5
|
Wilhelm RC, Pepe-Ranney C, Weisenhorn P, Lipton M, Buckley DH. Competitive Exclusion and Metabolic Dependency among Microorganisms Structure the Cellulose Economy of an Agricultural Soil. mBio 2021; 12:e03099-20. [PMID: 33402535 DOI: 10.1128/mBio.03099-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microorganisms that degrade cellulose utilize extracellular reactions that yield free by-products which can promote interactions with noncellulolytic organisms. We hypothesized that these interactions determine the ecological and physiological traits governing the fate of cellulosic carbon (C) in soil. We performed comparative genomics with genome bins from a shotgun metagenomic-stable isotope probing experiment to characterize the attributes of cellulolytic and noncellulolytic taxa accessing 13C from cellulose. We hypothesized that cellulolytic taxa would exhibit competitive traits that limit access, while noncellulolytic taxa would display greater metabolic dependency, such as signatures of adaptive gene loss. We tested our hypotheses by evaluating genomic traits indicative of competitive exclusion or metabolic dependency, such as antibiotic production, growth rate, surface attachment, biomass degrading potential, and auxotrophy. The most 13C-enriched taxa were cellulolytic Cellvibrio (Gammaproteobacteria) and Chaetomium (Ascomycota), which exhibited a strategy of self-sufficiency (prototrophy), rapid growth, and competitive exclusion via antibiotic production. Auxotrophy was more prevalent in cellulolytic Actinobacteria than in cellulolytic Proteobacteria, demonstrating differences in dependency among cellulose degraders. Noncellulolytic taxa that accessed 13C from cellulose (Planctomycetales, Verrucomicrobia, and Vampirovibrionales) were also more dependent, as indicated by patterns of auxotrophy and 13C labeling (i.e., partial labeling or labeling at later stages). Major 13C-labeled cellulolytic microbes (e.g., Sorangium, Actinomycetales, Rhizobiales, and Caulobacteraceae) possessed adaptations for surface colonization (e.g., gliding motility, hyphae, attachment structures) signifying the importance of surface ecology in decomposing particulate organic matter. Our results demonstrated that access to cellulosic C was accompanied by ecological trade-offs characterized by differing degrees of metabolic dependency and competitive exclusion.
Collapse
|
6
|
Albright MBN, Johansen R, Thompson J, Lopez D, Gallegos-Graves LV, Kroeger ME, Runde A, Mueller RC, Washburne A, Munsky B, Yoshida T, Dunbar J. Soil Bacterial and Fungal Richness Forecast Patterns of Early Pine Litter Decomposition. Front Microbiol 2020; 11:542220. [PMID: 33240225 PMCID: PMC7677502 DOI: 10.3389/fmicb.2020.542220] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 10/13/2020] [Indexed: 12/22/2022] Open
Abstract
Discovering widespread microbial processes that drive unexpected variation in carbon cycling may improve modeling and management of soil carbon (Prescott, 2010; Wieder et al., 2015a, 2018). A first step is to identify community features linked to carbon cycle variation. We addressed this challenge using an epidemiological approach with 206 soil communities decomposing Ponderosa pine litter in 618 microcosms. Carbon flow from litter decomposition was measured over a 6-week incubation. Cumulative CO2 from microbial respiration varied two-fold among microcosms and dissolved organic carbon (DOC) from litter decomposition varied five-fold, demonstrating large functional variation despite constant environmental conditions where strong selection is expected. To investigate microbial features driving DOC concentration, two microbial community cohorts were delineated as "high" and "low" DOC. For each cohort, communities from the original soils and from the final microcosm communities after the 6-week incubation with litter were taxonomically profiled. A logistic model including total biomass, fungal richness, and bacterial richness measured in the original soils or in the final microcosm communities predicted the DOC cohort with 72 (P < 0.05) and 80 (P < 0.001) percent accuracy, respectively. The strongest predictors of the DOC cohort were biomass and either fungal richness (in the original soils) or bacterial richness (in the final microcosm communities). Successful forecasting of functional patterns after lengthy community succession in a new environment reveals strong historical contingencies. Forecasting future community function is a key advance beyond correlation of functional variance with end-state community features. The importance of taxon richness-the same feature linked to carbon fate in gut microbiome studies-underscores the need for increased understanding of biotic mechanisms that can shape richness in microbial communities independent of physicochemical conditions.
Collapse
Affiliation(s)
| | - Renee Johansen
- Biosciences Division, Los Alamos National Laboratory, Los Alamos, NM, United States
| | - Jaron Thompson
- Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO, United States
| | - Deanna Lopez
- Biosciences Division, Los Alamos National Laboratory, Los Alamos, NM, United States
| | | | - Marie E. Kroeger
- Biosciences Division, Los Alamos National Laboratory, Los Alamos, NM, United States
| | - Andreas Runde
- Biosciences Division, Los Alamos National Laboratory, Los Alamos, NM, United States
| | - Rebecca C. Mueller
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, United States
| | - Alex Washburne
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Brian Munsky
- Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO, United States
- School of Biomedical Engineering, Colorado State University, Fort Collins, CO, United States
| | - Thomas Yoshida
- Chemical Diagnostics and Engineering, Los Alamos National Laboratory, Los Alamos, NM, United States
| | - John Dunbar
- Biosciences Division, Los Alamos National Laboratory, Los Alamos, NM, United States
| |
Collapse
|
7
|
Kopittke PM, Hernandez-Soriano MC, Dalal RC, Finn D, Menzies NW, Hoeschen C, Mueller CW. Nitrogen-rich microbial products provide new organo-mineral associations for the stabilization of soil organic matter. Glob Chang Biol 2018; 24:1762-1770. [PMID: 29211318 DOI: 10.1111/gcb.14009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 11/13/2017] [Indexed: 05/07/2023]
Abstract
Understanding the cycling of C and N in soils is important for maintaining soil fertility while also decreasing greenhouse gas emissions, but much remains unknown about how organic matter (OM) is stabilized in soils. We used nano-scale secondary ion mass spectrometry (NanoSIMS) to investigate the changes in C and N in a Vertisol and an Alfisol incubated for 365 days with 13 C and 15 N pulse labeled lucerne (Medicago sativa L.) to discriminate new inputs of OM from the existing soil OM. We found that almost all OM within the free stable microaggregates of the soil was associated with mineral particles, emphasizing the importance of organo-mineral interactions for the stabilization of C. Of particular importance, it was also found that 15 N-rich microbial products originating from decomposition often sorbed directly to mineral surfaces not previously associated with OM. Thus, we have shown that N-rich microbial products preferentially attach to distinct areas of mineral surfaces compared to C-dominated moieties, demonstrating the ability of soils to store additional OM in newly formed organo-mineral associations on previously OM-free mineral surfaces. Furthermore, differences in 15 N enrichment were observed between the Vertisol and Alfisol presumably due to differences in mineralogy (smectite-dominated compared to kaolinite-dominated), demonstrating the importance of mineralogy in regulating the sorption of microbial products. Overall, our findings have important implications for the fundamental understanding of OM cycling in soils, including the immobilization and storage of N-rich compounds derived from microbial decomposition and subsequent N mineralization to sustain plant growth.
Collapse
Affiliation(s)
- Peter M Kopittke
- School of Agriculture and Food Sciences, The University of Queensland, St. Lucia, Qld, Australia
| | | | - Ram C Dalal
- School of Agriculture and Food Sciences, The University of Queensland, St. Lucia, Qld, Australia
| | - Damien Finn
- School of Agriculture and Food Sciences, The University of Queensland, St. Lucia, Qld, Australia
| | - Neal W Menzies
- School of Agriculture and Food Sciences, The University of Queensland, St. Lucia, Qld, Australia
| | - Carmen Hoeschen
- Lehrstuhl für Bodenkunde, Technische Universität München, Freising, Germany
| | - Carsten W Mueller
- Lehrstuhl für Bodenkunde, Technische Universität München, Freising, Germany
| |
Collapse
|
8
|
Zhang R, Zhao Y, He HB, Zhang XD. [Investigation on effects of elevated atmospheric CO 2 concentration on plant-soil system carbon cycling: Based on stable isotopic technique]. Ying Yong Sheng Tai Xue Bao 2017; 28:2379-2388. [PMID: 29741073 DOI: 10.13287/j.1001-9332.201707.034] [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] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Elevated atmospheric CO2 affects plant photosynthesis process and biomass accumulation, furthermore alters the distribution of photosynthetic carbon (C) above- and below-ground. The formation and turnover of soil organic carbon (SOC) depends on the input of photosynthetic C, so the change of plant physiology and metabolism caused by increasing CO2 concentration will further affect the balance of SOC pool. Therefore, stable isotope 13C technique is powerful for clarifying the influence of elevated atmospheric CO2 on C cycling in plant-soil system, including the distribution of photosynthetic C among plant organs, and the transformation and accumulation of photosynthetic C in soil. This review summarized research focused on the effects of elevated atmospheric CO2 on C cycling in terrestrial ecosystems based on 13C natural abundance or 13C tracing technique, including: 1) isotopic fractionation effect in plant photosynthesis; 2) the distribution of photosynthetic C in plant organs; 3) the transformation and stabilization of photosynthetic C in SOC driven by microbial process. Clarifying the above processes and controlling mechanisms is essential to predict long-term influence of elevated CO2 on C cycling and evaluate the source-sink function of SOC in terrestrial ecosystems.
Collapse
Affiliation(s)
- Rui Zhang
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Zhao
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong Bo He
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Xu Dong Zhang
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| |
Collapse
|
9
|
Abstract
Management practices and environmental changes can alter soil nutrient and carbon cycling. Soil labile organic carbon, a readily decomposable C pool, is highly sensitive to disturbance. It is also the primary substrate for soil microorganisms, which is fundamental to nutrient cycling. Due to these attributes, labile organic carbon (LOC) has been identified as an indicator parameter for soil health. Quantifying the turnover rate of LOC also aids in understanding changes in soil nutrient cycling processes. A sequential fumigation incubation method has been developed to estimate soil LOC and potential C turnover rate. The method requires fumigating soil samples and quantifying CO2-C respired during a 10 day incubation period over a series of fumigation-incubation cycles. Labile organic C and potential C turnover rate are then extrapolated from accumulated CO2 with a negative exponential model. Procedures for conducting this method are described.
Collapse
Affiliation(s)
- Michael A Blazier
- Hill Farm Research Station, Louisiana State University Agricultural Center;
| | - Hal O Liechty
- School of Forestry and Natural Resources, University of Arkansas at Monticello
| |
Collapse
|
10
|
Parker TC, Subke JA, Wookey PA. Rapid carbon turnover beneath shrub and tree vegetation is associated with low soil carbon stocks at a subarctic treeline. Glob Chang Biol 2015; 21:2070-81. [PMID: 25367088 PMCID: PMC4657486 DOI: 10.1111/gcb.12793] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Revised: 09/22/2014] [Accepted: 10/16/2014] [Indexed: 05/05/2023]
Abstract
Climate warming at high northern latitudes has caused substantial increases in plant productivity of tundra vegetation and an expansion of the range of deciduous shrub species. However significant the increase in carbon (C) contained within above-ground shrub biomass, it is modest in comparison with the amount of C stored in the soil in tundra ecosystems. Here, we use a 'space-for-time' approach to test the hypothesis that a shift from lower-productivity tundra heath to higher-productivity deciduous shrub vegetation in the sub-Arctic may lead to a loss of soil C that out-weighs the increase in above-ground shrub biomass. We further hypothesize that a shift from ericoid to ectomycorrhizal systems coincident with this vegetation change provides a mechanism for the loss of soil C. We sampled soil C stocks, soil surface CO2 flux rates and fungal growth rates along replicated natural transitions from birch forest (Betula pubescens), through deciduous shrub tundra (Betula nana) to tundra heaths (Empetrum nigrum) near Abisko, Swedish Lapland. We demonstrate that organic horizon soil organic C (SOCorg ) is significantly lower at shrub (2.98 ± 0.48 kg m(-2) ) and forest (2.04 ± 0.25 kg m(-2) ) plots than at heath plots (7.03 ± 0.79 kg m(-2) ). Shrub vegetation had the highest respiration rates, suggesting that despite higher rates of C assimilation, C turnover was also very high and less C is sequestered in the ecosystem. Growth rates of fungal hyphae increased across the transition from heath to shrub, suggesting that the action of ectomycorrhizal symbionts in the scavenging of organically bound nutrients is an important pathway by which soil C is made available to microbial degradation. The expansion of deciduous shrubs onto potentially vulnerable arctic soils with large stores of C could therefore represent a significant positive feedback to the climate system.
Collapse
Affiliation(s)
- Thomas C Parker
- Biological and Environmental Sciences, School of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK; Department of Animal and Plant Sciences, Alfred Denny Building, University of Sheffield, Sheffield, S10 2TN, UK
| | | | | |
Collapse
|