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Bicharanloo B, Bagheri Shirvan M, Cavagnaro TR, Keitel C, Dijkstra FA. Nitrogen addition and defoliation alter belowground carbon allocation with consequences for plant nitrogen uptake and soil organic carbon decomposition. Sci Total Environ 2022; 846:157430. [PMID: 35863579 DOI: 10.1016/j.scitotenv.2022.157430] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/29/2022] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
Grassland plants allocate photosynthetically fixed carbon (C) belowground to root biomass and rhizodeposition, but also to support arbuscular mycorrhizal fungi (AMF). These C allocation pathways could increase nutrient scavenging, but also mining of nutrients through enhanced organic matter decomposition. While important for grassland ecosystem functioning, methodological constraints have limited our ability to measure these processes under field conditions. We used 13CO2 and 15N pulse labelling methods to examine belowground C allocation to root biomass production, rhizodeposition and AMF colonisation during peak plant growth in a grassland field experiment after three years of N fertilisation (0 and 40 kg N ha-1 year-1) and defoliation frequency treatments ("low" and "high", with 3-4 and 6-8 simulated grazing events per year, mimicking moderate and intense grazing, respectively). Moreover, we quantified the consequences for plant nitrogen (N) uptake and decomposition of soil organic C (SOC). Nitrogen fertilisation increased rhizodeposition and AMF colonisation (by 63 % and 54 %), but reduced root biomass (by 25 %). With high defoliation frequency, AMF colonisation increased (by 60 %), but both root biomass and rhizodeposition declined (by 35 % and 58 %). Plant N uptake was highest without N fertilisation and low defoliation frequency, and positively related to root biomass and the number of root tips. Therefore, when N supply is low and the capacity to produce C through photosynthesis is high, belowground C allocation to root production and associated root tips was important to scavenge for N in the soil. In contrast, the strong positive relationship between the rate of rhizodeposition and SOC decomposition, suggests that rhizodeposition may help plants to mine for nutrients locked in SOC. Taken together, the results of this study suggest that belowground C allocation pathways affected by N fertilisation and defoliation frequency affect plant N scavenging and mining with important consequences for long-term grassland C dynamics.
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Affiliation(s)
- Bahareh Bicharanloo
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Camden, NSW 2570, Australia.
| | - Milad Bagheri Shirvan
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Camden, NSW 2570, Australia
| | - Timothy R Cavagnaro
- School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Claudia Keitel
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Camden, NSW 2570, Australia
| | - Feike A Dijkstra
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Camden, NSW 2570, Australia
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2
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Huo Y, Dijkstra FA, Possell M, Singh B. Ecotoxicological effects of plastics on plants, soil fauna and microorganisms: A meta-analysis. Environ Pollut 2022; 310:119892. [PMID: 35932895 DOI: 10.1016/j.envpol.2022.119892] [Citation(s) in RCA: 5] [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] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 07/29/2022] [Accepted: 07/31/2022] [Indexed: 01/10/2023]
Abstract
The interactions of plastics and soil organisms are complex and inconsistent observations on the effects of plastics have been made in published studies. In this study, we assessed the effects of plastic exposure on plants, fauna and microbial communities, with a meta-analysis. Using a total of 2936 observations from 140 publications, we analysed how responses in plants, soil fauna and microorganisms depended on the plastic concentration, size, type, species and exposure media. We found that overall plastics caused substantial detrimental effects to plants and fauna, but less so to microbial diversity and richness. Plastic concentration was one of the most important factors explaining variations in plant and faunal responses. Larger plastics (>1 μm) caused unfavourable changes to plant growth, germination and oxidative stress, while nanoplastics (NPs; ≤ 1 μm) only increased oxidative stress. On the contrary, there was a clear trend showing that small plastics adversely affected fauna reproduction, survival and locomotion than large plastics. Plant responses were indifferent to plastic type, with most studies conducted using polyethylene (PE) and polystyrene (PS) plastics, but soil fauna were frequently more sensitive to PS than to PE exposure. Plant species played a vital role in some parameters, with the effects of plastics being considerably greater on vegetable plants than on cereal plants.
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Affiliation(s)
- Yuxin Huo
- Biomedical Building, 3 Central Ave, School of Life and Environmental Sciences, University of Sydney, Eveleigh, Sydney, NSW, 2015, Australia.
| | - Feike A Dijkstra
- Biomedical Building, 3 Central Ave, School of Life and Environmental Sciences, University of Sydney, Eveleigh, Sydney, NSW, 2015, Australia
| | - Malcolm Possell
- Biomedical Building, 3 Central Ave, School of Life and Environmental Sciences, University of Sydney, Eveleigh, Sydney, NSW, 2015, Australia
| | - Balwant Singh
- Biomedical Building, 3 Central Ave, School of Life and Environmental Sciences, University of Sydney, Eveleigh, Sydney, NSW, 2015, Australia
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3
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Lu J, Yang J, Keitel C, Yin L, Wang P, Cheng W, Dijkstra FA. Belowground Carbon Efficiency for Nitrogen and Phosphorus Acquisition Varies Between Lolium perenne and Trifolium repens and Depends on Phosphorus Fertilization. Front Plant Sci 2022; 13:927435. [PMID: 35812934 PMCID: PMC9263692 DOI: 10.3389/fpls.2022.927435] [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] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Accepted: 06/03/2022] [Indexed: 06/15/2023]
Abstract
Photosynthetically derived carbon (C) is allocated belowground, allowing plants to obtain nutrients. However, less is known about the amount of nutrients acquired relative to the C allocated belowground, which is referred to as C efficiency for nutrient acquisition (CENA). Here, we examined how C efficiency for nitrogen (N) and phosphorus (P) acquisition varied between ryegrass (Lolium perenne) and clover (Trifolium repens) with and without P fertilization. A continuous 13C-labeling method was applied to track belowground C allocation. Both species allocated nearly half of belowground C to rhizosphere respiration (49%), followed by root biomass (37%), and rhizodeposition (14%). With regard to N and P, CENA was higher for clover than for ryegrass, which remained higher after accounting for relatively low C costs associated with biological N2 fixation. Phosphorus fertilization increased the C efficiency for P acquisition but decreased the C efficiency for N acquisition. A higher CENA for N and P in clover may be attributed to the greater rhizosphere priming on soil organic matter decomposition. Increased P availability with P fertilization could induce lower C allocation for P uptake but exacerbate soil N limitation, thereby making N uptake less C efficient. Overall, our study revealed that species-specific belowground C allocation and nutrient uptake efficiency depend on which nutrient is limited.
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Affiliation(s)
- Jiayu Lu
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
- School of Life and Environmental Sciences, Sydney Institute of Agriculture, The University of Sydney, Sydney, NSW, Australia
| | - Jinfeng Yang
- National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, College of Land and Environment, Shenyang Agricultural University, Shenyang, China
| | - Claudia Keitel
- School of Life and Environmental Sciences, Sydney Institute of Agriculture, The University of Sydney, Sydney, NSW, Australia
| | - Liming Yin
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Peng Wang
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Weixin Cheng
- Environmental Studies Department, University of California, Santa Cruz, Santa Cruz, CA, United States
| | - Feike A. Dijkstra
- School of Life and Environmental Sciences, Sydney Institute of Agriculture, The University of Sydney, Sydney, NSW, Australia
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4
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Ding F, Ji D, Yan K, Dijkstra FA, Bao X, Li S, Kuzyakov Y, Wang J. Increased soil organic matter after 28 years of nitrogen fertilization only with plastic film mulching is controlled by maize root biomass. Sci Total Environ 2022; 810:152244. [PMID: 34896135 DOI: 10.1016/j.scitotenv.2021.152244] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 12/03/2021] [Accepted: 12/04/2021] [Indexed: 06/14/2023]
Abstract
Nitrogen (N) fertilization and plastic film mulching (PFM) are two widely applied management practices for crop production. Both of them impact soil organic matter individually, but their interactive effects as well as the underlying mechanisms are unknown. Soils from a 28-year field experiment with maize monoculture under three levels of N fertilization (0, 135, and 270 kg N ha-1 yr-1) and with or without PFM were analyzed for soil organic C (SOC) content, total soil nitrogen (N), root biomass, enzyme activities, and SOC mineralization rates. After 28 years, N fertilization increased root biomass and consequently, SOC by 26% (averaged across the two fertilizer application rates) and total soil N by 25%. These increases, however, were only in soil with PFM, as PFM reduced N leaching and loss, as a result of a diurnal internal water cycle under the mulch. The SOC mineralization was slower with N fertilization, regardless of the PFM treatment. This trend was attributed to the 43% decrease of β-glucosidase activity (C cycle enzyme) and 51% drop of leucine aminopeptidase (N cycle) with N fertilization, as a result of a strong decrease in soil pH. In conclusion, root biomass acting as the main source of soil C, resulted in an increase of soil organic matter after 28 year of N fertilization only with PFM.
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Affiliation(s)
- Fan Ding
- College of Land and Environment, Shenyang Agricultural University, Shenyang 110866, China.
| | - Dechang Ji
- College of Land and Environment, Shenyang Agricultural University, Shenyang 110866, China
| | - Kang Yan
- College of Land and Environment, Shenyang Agricultural University, Shenyang 110866, China; Institute of Soil and Water Resources and Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Feike A Dijkstra
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Eveleigh, NSW 2015, Australia
| | - Xuelian Bao
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Shuangyi Li
- College of Land and Environment, Shenyang Agricultural University, Shenyang 110866, China
| | - Yakov Kuzyakov
- Department of Soil Science of Temperate Ecosystems, Department of Agricultural Soil Science, University of Gottingen, Göttingen 37077, Germany; Laboratory of Conservation and Dynamic of Volcanic Soils, Department of Chemical Sciences and Natural Resources, Universidad de La Frontera, Temuco, Chile; Agro-Technological Institute, RUDN University, 117198 Moscow, Tyumen State University, 625003 Tyumen, Russia
| | - Jingkuan Wang
- College of Land and Environment, Shenyang Agricultural University, Shenyang 110866, China.
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Wang R, Yang J, Liu H, Sardans J, Zhang Y, Wang X, Wei C, Lü X, Dijkstra FA, Jiang Y, Han X, Peñuelas J. Nitrogen enrichment buffers phosphorus limitation by mobilizing mineral-bound soil phosphorus in grasslands. Ecology 2021; 103:e3616. [PMID: 34923633 DOI: 10.1002/ecy.3616] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 09/29/2021] [Accepted: 10/15/2021] [Indexed: 11/11/2022]
Abstract
Phosphorus (P) limitation is expected to increase due to nitrogen (N)-induced terrestrial eutrophication, although most soils contain large P pools immobilized in minerals (Pi ) and organic matter (Po ). Here we assessed whether transformations of these P pools can increase plant available pools alleviating P limitation under enhanced N availability. The mechanisms underlying these possible transformations were explored by combining results from a 10-year field N-addition experiment and a 3700-km transect covering wide ranges in soil pH, soil N, aridity, leaching, and weathering that can affect soil P status in grasslands. Nitrogen addition promoted dissolution of immobile Pi (mainly Ca-bound recalcitrant P) to more available forms of Pi (including Al- and Fe-bound P fractions and Olsen P) by decreasing soil pH from 7.6 to 4.7, but did not affect Po . Soil total P declined by 10% from 385 ± 6.8 to 346 ± 9.5 mg kg-1 , while available-P increased by 546% from 3.5 ± 0.3 to 22.6 ± 2.4 mg kg-1 after 10-year N addition, associated with an increase in Pi mobilization, plant uptake, and leaching. Similar to the N-addition experiment, the drop in soil pH from 7.5 to 5.6 and increase in soil N concentration along the grassland transect were associated with an increased ratio between relatively mobile Pi and immobile Pi . Our results provide a new mechanistic understanding of the important role of soil Pi mobilization in maintaining plant P supply and accelerating biogeochemical P cycles under anthropogenic N enrichment. This mobilization process temporarily buffers ecosystem P-limitation or even causes P eutrophication but will extensively deplete soil P pools in the long run. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Ruzhen Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China.,Erguna Forest-Steppe Ecotone Ecosystem Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Junjie Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Heyong Liu
- Erguna Forest-Steppe Ecotone Ecosystem Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Jordi Sardans
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, Catalonia, Spain.,CREAF, Cerdanyola del Vallès, Catalonia, Spain
| | - Yunhai Zhang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Xiaobo Wang
- Erguna Forest-Steppe Ecotone Ecosystem Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Cunzheng Wei
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Xiaotao Lü
- Erguna Forest-Steppe Ecotone Ecosystem Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Feike A Dijkstra
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Camden, New South Wales, Australia
| | - Yong Jiang
- Erguna Forest-Steppe Ecotone Ecosystem Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Xingguo Han
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China.,College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Josep Peñuelas
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, Catalonia, Spain.,CREAF, Cerdanyola del Vallès, Catalonia, Spain
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6
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Bicharanloo B, Cavagnaro TR, Keitel C, Dijkstra FA. Nitrogen Fertilisation Increases Specific Root Respiration in Ectomycorrhizal but Not in Arbuscular Mycorrhizal Plants: A Meta-Analysis. Front Plant Sci 2021; 12:711720. [PMID: 34421960 PMCID: PMC8377726 DOI: 10.3389/fpls.2021.711720] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 07/12/2021] [Indexed: 06/13/2023]
Abstract
Plants spend a high proportion of their photosynthetically fixed carbon (C) belowground to support mycorrhizal associations in return for nutrients, but this C expenditure may decrease with increased soil nutrient availability. In this study, we assessed how the effects of nitrogen (N) fertiliser on specific root respiration (SRR) varied among mycorrhizal type (Myco type). We conducted a multi-level meta-analysis across 1,600 observations from 32 publications. SRR increased in ectomycorrhizal (ECM) plants with more than 100 kg N ha-1 applied, did not change in arbuscular mycorrhizal (AM) and non-mycorrhizal (NM) plants, but increased in plants with a dual mycorrhizal association in response to N fertilisation. Our results suggest that high N availability (>100 kg N ha-1) could disadvantage the growth of ECM plants because of increased C costs associated with maintaining higher root N concentrations, while the insensitivity in SRR by AM plants to N fertilisation may be because AM fungi are more important for phosphorus (P) uptake.
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Affiliation(s)
- Bahareh Bicharanloo
- School of Life and Environmental Sciences, Sydney Institute of Agriculture, The University of Sydney, Camden, NSW, Australia
| | - Timothy R. Cavagnaro
- School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, SA, Australia
| | - Claudia Keitel
- School of Life and Environmental Sciences, Sydney Institute of Agriculture, The University of Sydney, Camden, NSW, Australia
| | - Feike A. Dijkstra
- School of Life and Environmental Sciences, Sydney Institute of Agriculture, The University of Sydney, Camden, NSW, Australia
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8
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Abstract
From recent developments on how roots affect soil organic carbon (SOC) an apparent paradox has emerged where roots drive SOC stabilization causing SOC accrual, but also SOC destabilization causing SOC loss. We synthesize current results and propose the new Rhizo-Engine framework consisting of two linked components: microbial turnover and the soil physicochemical matrix. The Rhizo-Engine is driven by rhizodeposition, root turnover, and plant uptake of nutrients and water, thereby accelerating SOC turnover through both stabilization and destabilization mechanisms. This Rhizo-Engine framework emphasizes the need for a more holistic approach to study root-driven SOC dynamics. This framework would provide better understanding of plant root effects on soil carbon sequestration and the sensitivity of SOC stocks to climate and land-use changes.
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Affiliation(s)
- Feike A Dijkstra
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Camden, NSW, 2570, Australia
| | - Biao Zhu
- Institute of Ecology, College of Urban and Environmental Sciences, Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, 100871, China
| | - Weixin Cheng
- Environmental Studies Department, University of California, Santa Cruz, CA, 95064, USA
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9
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Wang R, Bicharanloo B, Shirvan MB, Cavagnaro TR, Jiang Y, Keitel C, Dijkstra FA. A novel 13 C pulse-labelling method to quantify the contribution of rhizodeposits to soil respiration in a grassland exposed to drought and nitrogen addition. New Phytol 2021; 230:857-866. [PMID: 33253439 DOI: 10.1111/nph.17118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [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: 08/02/2020] [Accepted: 11/24/2020] [Indexed: 05/21/2023]
Abstract
Rhizodeposition plays an important role in below-ground carbon (C) cycling. However, quantification of rhizodeposition in intact plant-soil systems has remained elusive due to methodological issues. We used a 13 C-CO2 pulse-labelling method to quantify the contribution of rhizodeposition to below-ground respiration. Intact plant-soil cores were taken from a grassland field, and in half, shoots and roots were removed (unplanted cores). Both unplanted and planted cores were assigned to drought and nitrogen (N) treatments. Afterwards, shoots in planted cores were pulse labelled with 13 C-CO2 and then clipped to determine total below-ground respiration and its δ13 C. Simultaneously, δ13 C was measured for the respiration of live roots, soils with rhizodeposits, and unplanted treatments, and used as endmembers with which to determine root respiration and rhizodeposit C decomposition using two-source mixing models. Rhizodeposit decomposition accounted for 7-31% of total below-ground respiration. Drought reduced decomposition of both rhizodeposits and soil organic carbon (SOC), while N addition increased root respiration but not the contribution of rhizodeposit C decomposition to below-ground respiration. This study provides a new approach for the partitioning of below-ground respiration into different sources, and indicates that decomposition of rhizodeposit C is an important component of below-ground respiration that is sensitive to drought and N addition in grassland ecosystems.
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Affiliation(s)
- Ruzhen Wang
- Erguna Forest-Steppe Ecotone Ecosystem Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
- School of Life and Environmental Sciences, Sydney Institute of Agriculture, The University of Sydney, Camden, NSW, 2570, Australia
| | - Bahareh Bicharanloo
- School of Life and Environmental Sciences, Sydney Institute of Agriculture, The University of Sydney, Camden, NSW, 2570, Australia
| | - Milad Bagheri Shirvan
- School of Life and Environmental Sciences, Sydney Institute of Agriculture, The University of Sydney, Camden, NSW, 2570, Australia
| | - Timothy R Cavagnaro
- School of Agriculture, Food and Wine, The University of Adelaide, PMB 1, Glen Osmond, SA, 5065, Australia
| | - Yong Jiang
- Erguna Forest-Steppe Ecotone Ecosystem Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Claudia Keitel
- School of Life and Environmental Sciences, Sydney Institute of Agriculture, The University of Sydney, Camden, NSW, 2570, Australia
| | - Feike A Dijkstra
- School of Life and Environmental Sciences, Sydney Institute of Agriculture, The University of Sydney, Camden, NSW, 2570, Australia
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10
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Affiliation(s)
- Xiaohong Wang
- CAS Key Laboratory of Forest Ecology and Management Institute of Applied Ecology Chinese Academy of Sciences Shenyang China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Feike A. Dijkstra
- School of Life and Environmental Sciences Sydney Institute of Agriculture The University of Sydney Sydney New South Wales 2570 Australia
| | - Liming Yin
- CAS Key Laboratory of Forest Ecology and Management Institute of Applied Ecology Chinese Academy of Sciences Shenyang China
| | - Di Sun
- CAS Key Laboratory of Forest Ecology and Management Institute of Applied Ecology Chinese Academy of Sciences Shenyang China
| | - Weixin Cheng
- Environmental Studies Department University of California Santa Cruz California 95064 USA
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11
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Ullah MR, Corneo PE, Dijkstra FA. Inter-seasonal Nitrogen Loss with Drought Depends on Fertilizer Management in a Seminatural Australian Grassland. Ecosystems 2019. [DOI: 10.1007/s10021-019-00469-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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12
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Mehnaz KR, Keitel C, Dijkstra FA. Phosphorus availability and plants alter soil nitrogen retention and loss. Sci Total Environ 2019; 671:786-794. [PMID: 30943445 DOI: 10.1016/j.scitotenv.2019.03.422] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [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: 12/10/2018] [Revised: 03/26/2019] [Accepted: 03/26/2019] [Indexed: 06/09/2023]
Abstract
Availability of phosphorus (P) can directly and/or indirectly affect nitrogen (N) retention and loss from soil by stimulating microbial and plant root activities. However, it is not clear how P availability and plant presence interact on nitrous oxide (N2O) emission and nitrate (NO3-) leaching in soil. A mesocosm experiment was conducted to investigate the effect of P addition (0, 10 and 20 mg P kg-1) with and without plant presence (Phalaris aquatica, C3 grass) on N2O emission, NO3- leaching and 15N recovery. Our results showed large variation in N2O emission with significant increases after leaching events. We observed that initially low but later (after 53 days of sowing) high levels of P addition increased N2O emission rates, possibly by stimulating nitrifiers and/or denitrifiers in soil. Plant presence decreased N2O emission at times when plants reduced water and NO3- in the soil, but increased N2O emission at times when both water and NO3- in the soil were abundant, and where plants may have stimulated denitrification through supply of labile organic C. Furthermore, an increase in net N mineralization, possibly due to increased decomposition stimulated by root derived C, may also have contributed to the higher cumulative N2O emission with plant presence. P addition increased 15N recovery in soil, but reduced it in leachates, suggesting increased 15N fixation in microbial biomass. Our results showed that both P addition and plant presence stimulated N loss as N2O, but also increased N retention in the soil-plant system and thus reduced N loss through leaching.
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Affiliation(s)
- Kazi R Mehnaz
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, 380 Werombi Rd, Brownlow Hill, NSW 2570, Australia.
| | - Claudia Keitel
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, 380 Werombi Rd, Brownlow Hill, NSW 2570, Australia
| | - Feike A Dijkstra
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, 380 Werombi Rd, Brownlow Hill, NSW 2570, Australia
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13
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Hou J, Dijkstra FA, Zhang X, Wang C, Lü X, Wang P, Han X, Cheng W. Aridity thresholds of soil microbial metabolic indices along a 3,200 km transect across arid and semi-arid regions in Northern China. PeerJ 2019; 7:e6712. [PMID: 30993045 PMCID: PMC6461032 DOI: 10.7717/peerj.6712] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [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: 10/05/2018] [Accepted: 03/05/2019] [Indexed: 11/22/2022] Open
Abstract
Soil microbial processes are crucial for understanding the ecological functions of arid and semi-arid lands which occupy approximately 40% of the global terrestrial ecosystems. However, how soil microbial metabolic activities may change across a wide aridity gradient in drylands remains unclear. Here, we investigated three soil microbial metabolic indices (soil organic carbon (SOC)-based microbial respiration, metabolic quotient, and microbial biomass as a proportion of total SOC) and the degree of carbon limitation for microbial respiration along a 3,200 km transect with a wide aridity gradient. The aridity gradient was customarily expressed using the aridity index (AI) which was calculated as the ratio of mean annual precipitation to mean annual evaporation, therefore, a lower AI value indicated a higher degree of aridity. Our results showed non-linear relationships between AI values and the metabolic indices with a clear aridity threshold for each of the three metabolic indices along the aridity gradient, respectively (AI = 0.13 for basal respiration, AI = 0.17 for metabolic quotient, and AI = 0.17 for MBC:SOC ratio). These metabolic indices linearly declined when AI was above the thresholds, but did not show any clear patterns when AI was below the thresholds. We also found that soil microbial respiration was highly limited by available carbon substrates at locations with higher primary production and relatively lower level of water limitation when AI was above the threshold, a counter-intuitive pattern that microbes were more starved in ecosystems with more substrate input. However, the increasing level of carbon limitation did correspond to the declining trend of the three metabolic indices along the AI gradient, which indicates that the carbon limitation influences microbial metabolism. We also found that the ratio of microbial biomass carbon to SOC in arid regions (AI < 0.2) with extremely low precipitation and primary production were not quantitatively related to SOC content. Overall, our results imply that microbial metabolism is distinctively different in arid lands than in non-arid lands.
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Affiliation(s)
- Jianfeng Hou
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning, China.,University of Chinese Academy of Sciences, Beijing, Beijing, China
| | - Feike A Dijkstra
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, University of Sydney, Sydney, Camden, Australia
| | - Xiuwei Zhang
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning, China.,Institute of Wetland Ecology & Clone Ecology; Zhejiang Provincial Key Laboratory of Evolutionary Ecology and Conservation, Taizhou University, Taizhou, Zhejiang, China
| | - Chao Wang
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning, China
| | - Xiaotao Lü
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning, China
| | - Peng Wang
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning, China
| | - Xingguo Han
- Institute of Botany, Chinese Academy of Sciences, Beijing, Beijing, China
| | - Weixin Cheng
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning, China.,Environmental Studies Department, University of California, Santa Cruz, Santa Cruz, CA, USA
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14
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Chao L, Liu Y, Freschet GT, Zhang W, Yu X, Zheng W, Guan X, Yang Q, Chen L, Dijkstra FA, Wang S. Litter carbon and nutrient chemistry control the magnitude of soil priming effect. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13278] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Lin Chao
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology Chinese Academy of Sciences Shenyang China
- University of Chinese Academy of Sciences Beijing China
| | - Yanyan Liu
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education Guangxi Teachers Education University Nanning China
| | - Grégoire T. Freschet
- Centre d’Ecologie Fonctionnelle et Evolutive (CNRS—Université de Montpellier—Université Paul Valéry Montpellier—EPHE—IRD) Montpellier France
| | - Weidong Zhang
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology Chinese Academy of Sciences Shenyang China
- Huitong Experimental Station of Forest Ecology Chinese Academy of Sciences Huitong China
| | - Xin Yu
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology Chinese Academy of Sciences Shenyang China
- University of Chinese Academy of Sciences Beijing China
| | - Wenhui Zheng
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology Chinese Academy of Sciences Shenyang China
- University of Chinese Academy of Sciences Beijing China
| | - Xin Guan
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology Chinese Academy of Sciences Shenyang China
- Huitong Experimental Station of Forest Ecology Chinese Academy of Sciences Huitong China
| | - Qingpeng Yang
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology Chinese Academy of Sciences Shenyang China
- Huitong Experimental Station of Forest Ecology Chinese Academy of Sciences Huitong China
| | - Longchi Chen
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology Chinese Academy of Sciences Shenyang China
- Huitong Experimental Station of Forest Ecology Chinese Academy of Sciences Huitong China
| | - Feike A. Dijkstra
- Sydney Institute of Agriculture, School of Life and Environmental Sciences The University of Sydney Camden New South Wales Australia
| | - Silong Wang
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology Chinese Academy of Sciences Shenyang China
- Huitong Experimental Station of Forest Ecology Chinese Academy of Sciences Huitong China
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15
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Wang R, Zhang Y, He P, Yin J, Yang J, Liu H, Cai J, Shi Z, Feng X, Dijkstra FA, Han X, Jiang Y. Intensity and frequency of nitrogen addition alter soil chemical properties depending on mowing management in a temperate steppe. J Environ Manage 2018; 224:77-86. [PMID: 30031921 DOI: 10.1016/j.jenvman.2018.07.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [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: 04/16/2018] [Revised: 07/12/2018] [Accepted: 07/13/2018] [Indexed: 06/08/2023]
Abstract
Anthropogenic nitrogen (N) enrichment can significantly alter soil chemical properties in various ecosystems. Previous manipulative N experiments mainly focused on the intensity of N addition on soil properties by changing N input rates. It remains unclear, however, whether frequency of N addition can affect soil chemical properties. We examined the effects of frequency (2 versus 12 applications yr-1) and rate (ranging from 0 to 50 g N m-2 yr-1) of N addition on soil chemical properties of pH, base cations, soil pH buffering capacity (pHBC), and soil available micronutrients in a temperate steppe with and without mowing. Mowing significantly increased the effective cation exchange capacity (ECEC), soil exchangeable Ca and Na, available Fe, and soil pHBC when N was applied at low frequency. Low frequency of N addition significantly decreased soil pH and exchangeable Na but increased soil exchangeable Mg without mowing; however, it increased soil exchangeable Na and available Zn with mowing, while available Fe and Mn increased both with and without mowing. Higher rates of N addition (≥20 g N m-2 yr-1) decreased soil pH, ECEC and exchangeable Ca but increased soil available Fe, Mn and Cu regardless of the mowing treatment and frequency of N addition. Changes in soil organic matter, pHBC and ECEC were the main reasons affecting soil pH across mowing and N application treatments. Our results indicate that frequency of N addition played an essential role in altering soil chemical properties. Simulating N deposition via large and infrequent N additions can underestimate (exchangeable Mg and available Fe and Mn) or overestimate (soil pH and exchangeable Na) changes in soil properties. Our results further suggest that the effects of frequency of N addition on soil chemical attributes in semi-arid grassland ecosystems can be regulated by appropriate mowing management.
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Affiliation(s)
- Ruzhen Wang
- State Engineering Laboratory of Soil Nutrient and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Yunhai Zhang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Peng He
- State Engineering Laboratory of Soil Nutrient and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Jinfei Yin
- State Engineering Laboratory of Soil Nutrient and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Junjie Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Heyong Liu
- State Engineering Laboratory of Soil Nutrient and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Jiangping Cai
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Zhan Shi
- State Engineering Laboratory of Soil Nutrient and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Xue Feng
- State Engineering Laboratory of Soil Nutrient and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Feike A Dijkstra
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Xingguo Han
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Yong Jiang
- State Engineering Laboratory of Soil Nutrient and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
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16
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Luo W, Zuo X, Ma W, Xu C, Li A, Yu Q, Knapp AK, Tognetti R, Dijkstra FA, Li MH, Han G, Wang Z, Han X. Differential responses of canopy nutrients to experimental drought along a natural aridity gradient. Ecology 2018; 99:2230-2239. [PMID: 30157292 DOI: 10.1002/ecy.2444] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 06/05/2018] [Accepted: 06/18/2018] [Indexed: 01/31/2023]
Abstract
The allocation and stoichiometry of plant nutrients in leaves reflect fundamental ecosystem processes, biotic interactions, and environmental drivers such as water availability. Climate change will lead to increases in drought severity and frequency, but how canopy nutrients will respond to drought, and how these responses may vary with community composition along aridity gradients is poorly understood. We experimentally addressed this issue by reducing precipitation amounts by 66% during two consecutive growing seasons at three sites located along a natural aridity gradient. This allowed us to assess drought effects on canopy nitrogen (N) and phosphorus (P) concentrations in arid and semiarid grasslands of northern China. Along the aridity gradient, canopy nutrient concentrations were positively related to aridity, with this pattern was driven primarily by species turnover (i.e., an increase in the relative biomass of N- and P-rich species with increasing aridity). In contrast, drought imposed experimentally increased N but decreased P concentrations in plant canopies. These changes were driven by the combined effects of species turnover and intraspecific variation in leaf nutrient concentrations. In addition, the sensitivity of canopy N and P concentrations to drought varied across the three sites. Canopy nutrient concentrations were less affected by drought at drier than wetter sites, because of the opposing effects of species turnover and intraspecific variation, as well as greater drought tolerance for nutrient-rich species. These contrasting effects of long-term aridity vs. short-term drought on canopy nutrient concentrations, as well as differing sensitivities among sites in the same grassland biome, highlight the challenge of predicting ecosystem responses to future climate change.
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Affiliation(s)
- Wentao Luo
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110164, China
| | - Xiaoan Zuo
- Urat Desert-Grassland Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou, 730000, China
| | - Wang Ma
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110164, China
| | - Chong Xu
- National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 10008, China
| | - Ang Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Qiang Yu
- National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 10008, China
| | - Alan K Knapp
- Graduate Degree Program in Ecology and Department of Biology, Colorado State University, Fort Collins, Colorado, 80523, USA
| | - Roberto Tognetti
- Dipartimento di Agraria, Ambiente e Alimenti, Università del Molise, Campobasso, 86090, Italy.,European Forest Institute (EFI) Project Centre on Mountain Forests (MOUNTFOR), San Michele all'Adige, 38010, Italy
| | - Feike A Dijkstra
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Mai-He Li
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110164, China.,Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
| | - Guodong Han
- College of Ecology and Environmental Science, Inner Mongolia Agricultural University, Hohhot, 010018, China
| | - Zhengwen Wang
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110164, China
| | - Xingguo Han
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110164, China.,State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
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17
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Yin L, Dijkstra FA, Wang P, Zhu B, Cheng W. Rhizosphere priming effects on soil carbon and nitrogen dynamics among tree species with and without intraspecific competition. New Phytol 2018; 218:1036-1048. [PMID: 29512165 DOI: 10.1111/nph.15074] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [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: 10/26/2017] [Accepted: 02/04/2018] [Indexed: 06/08/2023]
Abstract
Rhizosphere priming effects (RPEs) play a central role in modifying soil organic matter mineralization. However, effects of tree species and intraspecific competition on RPEs are poorly understood. We investigated RPEs of three tree species (larch, ash and Chinese fir) and the impact of intraspecific competition of these species on the RPE by growing them at two planting densities for 140 d. We determined the RPE on soil organic carbon (C) decomposition, gross and net nitrogen (N) mineralization and net plant N acquisition. Differences in the RPE among species were associated with differences in plant biomass. Gross N mineralization and net plant N acquisition increased, but net N mineralization decreased, as the RPE on soil organic C decomposition increased. Intraspecific competition reduced the RPE on soil organic C decomposition, gross and net N mineralization, and net plant N acquisition, especially for ash and Chinese fir. Microbial N mining may explain the overall positive RPEs across species, whereas intensified plant-microbe competition for N may have reduced the RPE with intraspecific competition. Overall, the species-specific effects of tree species play an important role in modulating the magnitude and mechanisms of RPEs and the intraspecific competition on soil C and N dynamics.
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Affiliation(s)
- Liming Yin
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Feike A Dijkstra
- Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Camden, NSW, 2570, Australia
| | - Peng Wang
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Biao Zhu
- Department of Ecology, College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, 100871, China
| | - Weixin Cheng
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
- Environmental Studies Department, University of California, Santa Cruz, CA, 95064, USA
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18
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Canarini A, Mariotte P, Ingram L, Merchant A, Dijkstra FA. Mineral-Associated Soil Carbon is Resistant to Drought but Sensitive to Legumes and Microbial Biomass in an Australian Grassland. Ecosystems 2018. [PMID: 29540992 PMCID: PMC5840236 DOI: 10.1007/s10021-017-0152-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [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] [Indexed: 11/05/2022]
Abstract
Drought is predicted to increase in many areas of the world with consequences for soil carbon (C) dynamics. Plant litter, root exudates and microbial biomass can be used as C substrates to form organo-mineral complexes. Drought effects on plants and microbes could potentially compromise these relative stable soil C pools, by reducing plant C inputs and/or microbial activity. We conducted a 2-year drought experiment using rainout shelters in a semi-natural grassland. We measured aboveground biomass and C and nitrogen (N) in particulate organic matter (Pom), the organo-mineral fraction (Omin), and microbial biomass within the first 15 cm of soil. Aboveground plant biomass was reduced by 50% under drought in both years, but only the dominant C4 grasses were significantly affected. Soil C pools were not affected by drought, but were significantly higher in the relatively wet second year compared to the first year. Omin-C was positively related to microbial C during the first year, and positively related to clay and silt content in the second year. Increases in Omin-C in the second year were explained by increases in legume biomass and its effect on Pom-N and microbial biomass N (MBN) through structural equation modeling. In conclusion, soil C pools were unaffected by the drought treatment. Drought resistant legumes enhanced formation of organo-mineral complexes through increasing Pom-N and MBN. Our findings also indicate the importance of microbes for the formation of Omin-C as long as soil minerals have not reached their maximum capacity to bind with C (that is, saturation).
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Affiliation(s)
- Alberto Canarini
- 1Centre for Carbon, Water and Food, School of Life and Environmental Sciences, The University of Sydney, 380 Werombi Road, Camden, NSW 2570 Australia.,2Department of Microbiology and Ecosystem Science, University of Vienna, Althanstr. 14, 1090 Vienna, Austria
| | - Pierre Mariotte
- 1Centre for Carbon, Water and Food, School of Life and Environmental Sciences, The University of Sydney, 380 Werombi Road, Camden, NSW 2570 Australia.,3Laboratory of Ecological Systems (ECOS), School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 2, 1015 Lausanne, Switzerland.,4Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Site Lausanne, Case postale 96, 1015 Lausanne, Switzerland
| | - Lachlan Ingram
- 1Centre for Carbon, Water and Food, School of Life and Environmental Sciences, The University of Sydney, 380 Werombi Road, Camden, NSW 2570 Australia
| | - Andrew Merchant
- 1Centre for Carbon, Water and Food, School of Life and Environmental Sciences, The University of Sydney, 380 Werombi Road, Camden, NSW 2570 Australia
| | - Feike A Dijkstra
- 1Centre for Carbon, Water and Food, School of Life and Environmental Sciences, The University of Sydney, 380 Werombi Road, Camden, NSW 2570 Australia
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19
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Blumenthal DM, Mueller KE, Kray JA, LeCain DR, Pendall E, Duke S, Zelikova TJ, Dijkstra FA, Williams DG, Morgan JA. Warming and Elevated CO2 Interact to Alter Seasonality and Reduce Variability of Soil Water in a Semiarid Grassland. Ecosystems 2018. [DOI: 10.1007/s10021-018-0237-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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20
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Dijkstra FA, Carrillo Y, Blumenthal DM, Mueller KE, LeCain DR, Morgan JA, Zelikova TJ, Williams DG, Follett RF, Pendall E. Elevated CO 2 and water addition enhance nitrogen turnover in grassland plants with implications for temporal stability. Ecol Lett 2018; 21:674-682. [PMID: 29508508 DOI: 10.1111/ele.12935] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 11/20/2017] [Accepted: 02/08/2018] [Indexed: 11/28/2022]
Abstract
Temporal variation in soil nitrogen (N) availability affects growth of grassland communities that differ in their use and reuse of N. In a 7-year-long climate change experiment in a semi-arid grassland, the temporal stability of plant biomass production varied with plant N turnover (reliance on externally acquired N relative to internally recycled N). Species with high N turnover were less stable in time compared to species with low N turnover. In contrast, N turnover at the community level was positively associated with asynchrony in biomass production, which in turn increased community temporal stability. Elevated CO2 and summer irrigation, but not warming, enhanced community N turnover and stability, possibly because treatments promoted greater abundance of species with high N turnover. Our study highlights the importance of plant N turnover for determining the temporal stability of individual species and plant communities affected by climate change.
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Affiliation(s)
- Feike A Dijkstra
- School of Life and Environmental Sciences, Sydney Institute of Agriculture, The University of Sydney, Camden, 2570, NSW, Australia
| | - Yolima Carrillo
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, 2570, NSW, Australia
| | - Dana M Blumenthal
- Rangeland Resources & Systems Research Unit, Agricultural Research Service, United States Department of Agriculture, Fort Collins, CO, 80526, USA
| | - Kevin E Mueller
- Department of Biological, Geological, and Environmental Sciences, Cleveland State University, Cleveland, OH, 44115, USA
| | - Dan R LeCain
- Rangeland Resources & Systems Research Unit, Agricultural Research Service, United States Department of Agriculture, Fort Collins, CO, 80526, USA
| | - Jack A Morgan
- Rangeland Resources & Systems Research Unit, Agricultural Research Service, United States Department of Agriculture, Fort Collins, CO, 80526, USA
| | - Tamara J Zelikova
- Department of Botany, University of Wyoming, Laramie, WY, 82071, USA
| | - David G Williams
- Department of Botany, University of Wyoming, Laramie, WY, 82071, USA
| | - Ronald F Follett
- Agricultural Research Service, Soil Plant and Nutrient Research Unit, United States Department of Agriculture, Fort Collins, CO, 80526, USA
| | - Elise Pendall
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, 2570, NSW, Australia
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21
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Crowther TW, Machmuller MB, Carey JC, Allison SD, Blair JM, Bridgham SD, Burton AJ, Dijkstra FA, Elberling B, Estiarte M, Larsen KS, Laudon H, Lupascu M, Marhan S, Mohan J, Niu S, J Peñuelas J, Schmidt IK, Templer PH, Kröel-Dulay G, Frey S, Bradford MA. Crowther et al. reply. Nature 2018; 554:E7-E8. [PMID: 29469091 DOI: 10.1038/nature25746] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- T W Crowther
- Institute of Integrative Biology, ETH Zurich, Universitätstrasse 16, 8006 Zürich, Switzerland
| | - M B Machmuller
- Natural Resource Ecology Laboratory, 1 499 Campus Delivery, Colorado State University, Fort Collins, Colorado 80523-1499, USA
| | - J C Carey
- Division of Math and Science, Babson College, Massachusetts 02457, USA
| | - S D Allison
- Department of Earth System Science, University of California Irvine, Irvine, California 92697, USA.,Department of Ecology & Evolutionary Biology, University of California Irvine, Irvine, California 92697, USA
| | - J M Blair
- Division of Biology, Kansas State University, Manhattan, Kansas 66506, USA
| | - S D Bridgham
- Institute of Ecology & Evolution, University of Oregon, Eugene, Oregon 97403, USA
| | - A J Burton
- School of Forest Resources & Environmental Science, Michigan Technological University, Houghton, Michigan 49931, USA
| | - F A Dijkstra
- Centre for Carbon, Water & Food, The University of Sydney, Camden, 2570 New South Wales, Australia
| | - B Elberling
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, 1350 Copenhagen K., Denmark
| | - M Estiarte
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Cerdanyola del Vallès, 08193 Catalonia, Spain.,CREAF, Cerdanyola del Vallès, 08193 Catalonia, Spain
| | - K S Larsen
- Department of Geosciences & Natural Resource Management, University of Copenhagen, Rolighedsvej 23, 1958 Frederiksberg C, Denmark
| | - H Laudon
- Department of Forest Ecology & Management, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden
| | - M Lupascu
- Department of Geography, National University of Singapore, 1 Arts Link, 117570, Singapore
| | - S Marhan
- Institute of Soil Science & Land Evaluation, University of Hohenheim, 70593 Stuttgart, Germany
| | - J Mohan
- Odum School of Ecology, University of Georgia, Athens, Georgia 30601, USA
| | - S Niu
- Key Laboratory of Ecosystem Network Observation & Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - J J Peñuelas
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Cerdanyola del Vallès, 08193 Catalonia, Spain.,CREAF, Cerdanyola del Vallès, 08193 Catalonia, Spain
| | - I K Schmidt
- Department of Geosciences & Natural Resource Management, University of Copenhagen, Rolighedsvej 23, 1958 Frederiksberg C, Denmark
| | - P H Templer
- Department of Ecology & Evolutionary Biology, University of California Irvine, Irvine, California 92697, USA
| | - G Kröel-Dulay
- Institute of Ecology & Botany, MTA Centre for Ecological Research, 2-4. Alkotmany U., Vacratot, 2163-Hungary
| | - S Frey
- Department of Natural Resources & the Environment, University of New Hampshire, Durham, New Hampshire 03824, USA
| | - M A Bradford
- School of Forestry & Environmental Studies, Yale University, 195 Prospect Street, New Haven, Connecticut 06511, USA
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22
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van Groenigen KJ, Osenberg CW, Terrer C, Carrillo Y, Dijkstra FA, Heath J, Nie M, Pendall E, Phillips RP, Hungate BA. Faster turnover of new soil carbon inputs under increased atmospheric CO 2. Glob Chang Biol 2017; 23:4420-4429. [PMID: 28480591 DOI: 10.1111/gcb.13752] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [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: 11/29/2016] [Revised: 04/13/2017] [Accepted: 05/01/2017] [Indexed: 06/07/2023]
Abstract
Rising levels of atmospheric CO2 frequently stimulate plant inputs to soil, but the consequences of these changes for soil carbon (C) dynamics are poorly understood. Plant-derived inputs can accumulate in the soil and become part of the soil C pool ("new soil C"), or accelerate losses of pre-existing ("old") soil C. The dynamics of the new and old pools will likely differ and alter the long-term fate of soil C, but these separate pools, which can be distinguished through isotopic labeling, have not been considered in past syntheses. Using meta-analysis, we found that while elevated CO2 (ranging from 550 to 800 parts per million by volume) stimulates the accumulation of new soil C in the short term (<1 year), these effects do not persist in the longer term (1-4 years). Elevated CO2 does not affect the decomposition or the size of the old soil C pool over either temporal scale. Our results are inconsistent with predictions of conventional soil C models and suggest that elevated CO2 might increase turnover rates of new soil C. Because increased turnover rates of new soil C limit the potential for additional soil C sequestration, the capacity of land ecosystems to slow the rise in atmospheric CO2 concentrations may be smaller than previously assumed.
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Affiliation(s)
- Kees Jan van Groenigen
- Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, USA
| | | | - César Terrer
- AXA Chair Programme in Biosphere and Climate Impacts, Department of Life Sciences, Imperial College London, Ascot, UK
| | - Yolima Carrillo
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Feike A Dijkstra
- Centre for Carbon, Water and Food, School of Life and Environmental Sciences, The University of Sydney, Eveleigh, NSW, Australia
| | - James Heath
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Ming Nie
- Ministry of Education Key Lab for Biodiversity Science and Ecological Engineering, The Institute of Biodiversity Science, Fudan University, Shanghai, China
| | - Elise Pendall
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | | | - Bruce A Hungate
- Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
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23
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De Kauwe MG, Medlyn BE, Walker AP, Zaehle S, Asao S, Guenet B, Harper AB, Hickler T, Jain AK, Luo Y, Lu X, Luus K, Parton WJ, Shu S, Wang YP, Werner C, Xia J, Pendall E, Morgan JA, Ryan EM, Carrillo Y, Dijkstra FA, Zelikova TJ, Norby RJ. Challenging terrestrial biosphere models with data from the long-term multifactor Prairie Heating and CO 2 Enrichment experiment. Glob Chang Biol 2017; 23:3623-3645. [PMID: 28145053 DOI: 10.1111/gcb.13643] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [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: 11/14/2016] [Accepted: 01/15/2017] [Indexed: 06/06/2023]
Abstract
Multifactor experiments are often advocated as important for advancing terrestrial biosphere models (TBMs), yet to date, such models have only been tested against single-factor experiments. We applied 10 TBMs to the multifactor Prairie Heating and CO2 Enrichment (PHACE) experiment in Wyoming, USA. Our goals were to investigate how multifactor experiments can be used to constrain models and to identify a road map for model improvement. We found models performed poorly in ambient conditions; there was a wide spread in simulated above-ground net primary productivity (range: 31-390 g C m-2 yr-1 ). Comparison with data highlighted model failures particularly with respect to carbon allocation, phenology, and the impact of water stress on phenology. Performance against the observations from single-factors treatments was also relatively poor. In addition, similar responses were predicted for different reasons across models: there were large differences among models in sensitivity to water stress and, among the N cycle models, N availability during the experiment. Models were also unable to capture observed treatment effects on phenology: they overestimated the effect of warming on leaf onset and did not allow CO2 -induced water savings to extend the growing season length. Observed interactive (CO2 × warming) treatment effects were subtle and contingent on water stress, phenology, and species composition. As the models did not correctly represent these processes under ambient and single-factor conditions, little extra information was gained by comparing model predictions against interactive responses. We outline a series of key areas in which this and future experiments could be used to improve model predictions of grassland responses to global change.
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Affiliation(s)
- Martin G De Kauwe
- Department of Biological Science, Macquarie University, North Ryde, NSW, 2109, Australia
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Anthony P Walker
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN, 37831, USA
| | - Sönke Zaehle
- Biogeochemical Integration Department, Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
| | - Shinichi Asao
- Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO, 80523-1499, USA
| | - Bertrand Guenet
- Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, F-91191, Gif-sur-Yvette, France
| | - Anna B Harper
- College of Engineering, Mathematics, and Physical Sciences, University of Exeter, Exeter, EX4 4QF, UK
| | - Thomas Hickler
- Senckenberg Biodiversity and Climate Research Centre (BiK-F), Senckenberganlage 25, 60325, Frankfurt, Germany
- Department of Physical Geography, Geosciences, Goethe-University, Altenhöferallee 1, 60438, Frankfurt, Germany
| | - Atul K Jain
- Department of Atmospheric Sciences, University of Illinois, 105 South Gregory Street, Urbana, IL, 61801-3070, USA
| | - Yiqi Luo
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
| | - Xingjie Lu
- CSIRO Oceans and Atmosphere, Private Bag #1, Aspendale, Vic., 3195, Australia
| | - Kristina Luus
- Biogeochemical Integration Department, Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
| | - William J Parton
- Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO, 80523-1499, USA
| | - Shijie Shu
- Department of Atmospheric Sciences, University of Illinois, 105 South Gregory Street, Urbana, IL, 61801-3070, USA
| | - Ying-Ping Wang
- CSIRO Oceans and Atmosphere, Private Bag #1, Aspendale, Vic., 3195, Australia
| | - Christian Werner
- Senckenberg Biodiversity and Climate Research Centre (BiK-F), Senckenberganlage 25, 60325, Frankfurt, Germany
| | - Jianyang Xia
- Tiantong National Forest Ecosystem Observation and Research Station, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200062, China
| | - Elise Pendall
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Jack A Morgan
- Rangeland Resources Research Unit, Agricultural Research Service, United States Department of Agriculture, Fort Collins, CO, 80526, USA
| | - Edmund M Ryan
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YW, UK
| | - Yolima Carrillo
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Feike A Dijkstra
- Centre for Carbon, Water and Food, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Tamara J Zelikova
- Department of Botany, University of Wyoming, Laramie, WY, 82071, USA
| | - Richard J Norby
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN, 37831, USA
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Mueller KE, Blumenthal DM, Pendall E, Carrillo Y, Dijkstra FA, Williams DG, Follett RF, Morgan JA. Impacts of warming and elevated CO2 on a semi-arid grassland are non-additive, shift with precipitation, and reverse over time. Ecol Lett 2016; 19:956-66. [PMID: 27339693 DOI: 10.1111/ele.12634] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 04/01/2016] [Accepted: 05/15/2016] [Indexed: 12/28/2022]
Abstract
It is unclear how elevated CO2 (eCO2 ) and the corresponding shifts in temperature and precipitation will interact to impact ecosystems over time. During a 7-year experiment in a semi-arid grassland, the response of plant biomass to eCO2 and warming was largely regulated by interannual precipitation, while the response of plant community composition was more sensitive to experiment duration. The combined effects of eCO2 and warming on aboveground plant biomass were less positive in 'wet' growing seasons, but total plant biomass was consistently stimulated by ~ 25% due to unique, supra-additive responses of roots. Independent of precipitation, the combined effects of eCO2 and warming on C3 graminoids became increasingly positive and supra-additive over time, reversing an initial shift toward C4 grasses. Soil resources also responded dynamically and non-additively to eCO2 and warming, shaping the plant responses. Our results suggest grasslands are poised for drastic changes in function and highlight the need for long-term, factorial experiments.
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Affiliation(s)
- K E Mueller
- Rangeland Resources Research Unit, Agricultural Research Service, United States Department of Agriculture, Fort Collins, CO, 80526, USA
| | - D M Blumenthal
- Rangeland Resources Research Unit, Agricultural Research Service, United States Department of Agriculture, Fort Collins, CO, 80526, USA
| | - E Pendall
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, 2751, Australia
| | - Y Carrillo
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, 2751, Australia
| | - F A Dijkstra
- Centre for Carbon, Water and Food, Faculty of Agriculture and Environment, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - D G Williams
- Department of Botany, University of Wyoming, Laramie, WY, 82071, USA
| | - R F Follett
- Soil Plant and Nutrient Research Unit, Agricultural Research Service, United States Department of Agriculture, Fort Collins, CO, 80526, USA
| | - J A Morgan
- Rangeland Resources Research Unit, Agricultural Research Service, United States Department of Agriculture, Fort Collins, CO, 80526, USA
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Chen J, Carrillo Y, Pendall E, Dijkstra FA, Dave Evans R, Morgan JA, Williams DG. Soil Microbes Compete Strongly with Plants for Soil Inorganic and Amino Acid Nitrogen in a Semiarid Grassland Exposed to Elevated CO2 and Warming. Ecosystems 2015. [DOI: 10.1007/s10021-015-9868-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
Climate change scenarios forecast increased aridity in large areas worldwide with potentially important effects on nutrient availability and plant growth. Plant nitrogen and phosphorus concentrations (plant [N] and [P]) have been used to assess nutrient limitation, but a comprehensive understanding of drought stress on plant [N] and [P] remains elusive. We conducted a meta-analysis to examine responses of plant [N] and [P] to drought manipulation treatments and duration of drought stress. Drought stress showed negative effects on plant [N] (-3.73%) and plant [P] (-9.18%), and a positive effect on plant N:P (+ 6.98%). Drought stress had stronger negative effects on plant [N] and [P] in the short term (< 90 d) than in the long term (> 90 d). Drought treatments that included drying-rewetting cycles showed no effect on plant [N] and [P], while constant, prolonged, or intermittent drought stress had a negative effect on plant [P]. Our results suggest that negative effects on plant [N] and [P] are alleviated with extended duration of drought treatments and with drying-rewetting cycles. Availability of water, rather than of N and P, may be the main driver for reduced plant growth with increased long-term drought stress.
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Affiliation(s)
- Mingzhu He
- Shapotou Desert Research and Experiment Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, 730000, China
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He M, Dijkstra FA, Zhang K, Li X, Tan H, Gao Y, Li G. Leaf nitrogen and phosphorus of temperate desert plants in response to climate and soil nutrient availability. Sci Rep 2014; 4:6932. [PMID: 25373739 PMCID: PMC4221785 DOI: 10.1038/srep06932] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 10/14/2014] [Indexed: 11/21/2022] Open
Abstract
In desert ecosystems, plant growth and nutrient uptake are restricted by availability of soil nitrogen (N) and phosphorus (P). The effects of both climate and soil nutrient conditions on N and P concentrations among desert plant life forms (annual, perennial and shrub) remain unclear. We assessed leaf N and P levels of 54 desert plants and measured the corresponding soil N and P in shallow (0-10 cm), middle (10-40 cm) and deep soil layers (40-100 cm), at 52 sites in a temperate desert of northwest China. Leaf P and N:P ratios varied markedly among life forms. Leaf P was higher in annuals and perennials than in shrubs. Leaf N and P showed a negative relationship with mean annual temperature (MAT) and no relationship with mean annual precipitation (MAP), but a positive relationship with soil P. Leaf P of shrubs was positively related to soil P in the deep soil. Our study indicated that leaf N and P across the three life forms were influenced by soil P. Deep-rooted plants may enhance the availability of P in the surface soil facilitating growth of shallow-rooted life forms in this N and P limited system, but further research is warranted on this aspect.
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Affiliation(s)
- Mingzhu He
- Shapotou Desert Research and Experiment Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou. 730000, China
| | - Feike A. Dijkstra
- Department of Environmental Sciences, Centre for Carbon, Water and Food, The University of Sydney, NSW. 2006, Australia
| | - Ke Zhang
- Shapotou Desert Research and Experiment Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou. 730000, China
| | - Xinrong Li
- Shapotou Desert Research and Experiment Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou. 730000, China
- Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions of Gansu Province, Lanzhou. 730000, China
| | - Huijuan Tan
- Shapotou Desert Research and Experiment Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou. 730000, China
- Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions of Gansu Province, Lanzhou. 730000, China
| | - Yanhong Gao
- Shapotou Desert Research and Experiment Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou. 730000, China
| | - Gang Li
- Shapotou Desert Research and Experiment Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou. 730000, China
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Zhang QZ, Dijkstra FA, Liu XR, Wang YD, Huang J, Lu N. Effects of biochar on soil microbial biomass after four years of consecutive application in the north China Plain. PLoS One 2014; 9:e102062. [PMID: 25025330 PMCID: PMC4098902 DOI: 10.1371/journal.pone.0102062] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 06/15/2014] [Indexed: 11/18/2022] Open
Abstract
The long term effect of biochar application on soil microbial biomass is not well understood. We measured soil microbial biomass carbon (MBC) and nitrogen (MBN) in a field experiment during a winter wheat growing season after four consecutive years of no (CK), 4.5 (B4.5) and 9.0 t biochar ha(-1) yr(-1) (B9.0) applied. For comparison, a treatment with wheat straw residue incorporation (SR) was also included. Results showed that biochar application increased soil MBC significantly compared to the CK treatment, and that the effect size increased with biochar application rate. The B9.0 treatment showed the same effect on MBC as the SR treatment. Treatments effects on soil MBN were less strong than for MBC. The microbial biomass C∶N ratio was significantly increased by biochar. Biochar might decrease the fraction of biomass N mineralized (KN), which would make the soil MBN for biochar treatments underestimated, and microbial biomass C∶N ratios overestimated. Seasonal fluctuation in MBC was less for biochar amended soils than for CK and SR treatments, suggesting that biochar induced a less extreme environment for microorganisms throughout the season. There was a significant positive correlation between MBC and soil water content (SWC), but there was no significant correlation between MBC and soil temperature. Biochar amendments may therefore reduce temporal variability in environmental conditions for microbial growth in this system thereby reducing temporal fluctuations in C and N dynamics.
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Affiliation(s)
- Qing-zhong Zhang
- Key Laboratory of Agricultural Environment, Ministry of Agriculture, Sino-Australian Joint Laboratory For Sustainable Agro-Ecosystems, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
- * E-mail:
| | - Feike A. Dijkstra
- Centre for Carbon, Water and Food, Department of Environmental Sciences, The University of Sydney, Camden, New South Wales, Australia
| | - Xing-ren Liu
- Key Laboratory of Agricultural Environment, Ministry of Agriculture, Sino-Australian Joint Laboratory For Sustainable Agro-Ecosystems, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yi-ding Wang
- Key Laboratory of Agricultural Environment, Ministry of Agriculture, Sino-Australian Joint Laboratory For Sustainable Agro-Ecosystems, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jian Huang
- Key Laboratory of Agricultural Environment, Ministry of Agriculture, Sino-Australian Joint Laboratory For Sustainable Agro-Ecosystems, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Ning Lu
- Key Laboratory of Agricultural Environment, Ministry of Agriculture, Sino-Australian Joint Laboratory For Sustainable Agro-Ecosystems, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
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Lü XT, Dijkstra FA, Kong DL, Wang ZW, Han XG. Plant nitrogen uptake drives responses of productivity to nitrogen and water addition in a grassland. Sci Rep 2014; 4:4817. [PMID: 24769508 PMCID: PMC4001094 DOI: 10.1038/srep04817] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 04/09/2014] [Indexed: 11/24/2022] Open
Abstract
Increased atmospheric nitrogen (N) deposition and altered precipitation regimes have profound impacts on ecosystem functioning in semiarid grasslands. The interactions between those two factors remain largely unknown. A field experiment with N and water additions was conducted in a semiarid grassland in northern China. We examined the responses of aboveground net primary production (ANPP) and plant N use during two contrasting hydrological growing seasons. Nitrogen addition had no impact on ANPP, which may be accounted for by the offset between enhanced plant N uptake and decreased plant nitrogen use efficiency (NUE). Water addition significantly enhanced ANPP, which was largely due to enhanced plant aboveground N uptake. Nitrogen and water additions significantly interacted to affect ANPP, plant N uptake and N concentrations at the community level. Our observations highlight the important role of plant N uptake and use in mediating the effects of N and water addition on ANPP.
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Affiliation(s)
- Xiao-Tao Lü
- State Key Laboratory of Forest and Soil Ecology, Chinese Academy of Sciences, Shenyang 110164, China
| | - Feike A Dijkstra
- Department of Environmental Sciences, The University of Sydney, Camden, NSW, 2570, Australia
| | - De-Liang Kong
- School of Life Sciences, Henan University, Henan 475004, China
| | - Zheng-Wen Wang
- State Key Laboratory of Forest and Soil Ecology, Chinese Academy of Sciences, Shenyang 110164, China
| | - Xing-Guo Han
- State Key Laboratory of Forest and Soil Ecology, Chinese Academy of Sciences, Shenyang 110164, China
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30
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Pendall E, Heisler-White JL, Williams DG, Dijkstra FA, Carrillo Y, Morgan JA, LeCain DR. Warming reduces carbon losses from grassland exposed to elevated atmospheric carbon dioxide. PLoS One 2013; 8:e71921. [PMID: 23977180 PMCID: PMC3747065 DOI: 10.1371/journal.pone.0071921] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 07/03/2013] [Indexed: 11/18/2022] Open
Abstract
The flux of carbon dioxide (CO2) between terrestrial ecosystems and the atmosphere may ameliorate or exacerbate climate change, depending on the relative responses of ecosystem photosynthesis and respiration to warming temperatures, rising atmospheric CO2, and altered precipitation. The combined effect of these global change factors is especially uncertain because of their potential for interactions and indirectly mediated conditions such as soil moisture. Here, we present observations of CO2 fluxes from a multi-factor experiment in semi-arid grassland that suggests a potentially strong climate – carbon cycle feedback under combined elevated [CO2] and warming. Elevated [CO2] alone, and in combination with warming, enhanced ecosystem respiration to a greater extent than photosynthesis, resulting in net C loss over four years. The effect of warming was to reduce respiration especially during years of below-average precipitation, by partially offsetting the effect of elevated [CO2] on soil moisture and C cycling. Carbon losses were explained partly by stimulated decomposition of soil organic matter with elevated [CO2]. The climate – carbon cycle feedback observed in this semiarid grassland was mediated by soil water content, which was reduced by warming and increased by elevated [CO2]. Ecosystem models should incorporate direct and indirect effects of climate change on soil water content in order to accurately predict terrestrial feedbacks and long-term storage of C in soil.
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Affiliation(s)
- Elise Pendall
- Department of Botany and Program in Ecology, University of Wyoming, Laramie, Wyoming, United States of America
- * E-mail:
| | - Jana L. Heisler-White
- United States Department of Agriculture – Agricultural Research Service, Rangeland Resources Research Unit and Northern Plains Area, Fort Collins, Colorado, United States of America
- Departments of Botany; Ecosystem Science and Management, and Program in Ecology, University of Wyoming, Laramie, Wyoming, United States of America
| | - David G. Williams
- Departments of Botany; Ecosystem Science and Management, and Program in Ecology, University of Wyoming, Laramie, Wyoming, United States of America
| | - Feike A. Dijkstra
- United States Department of Agriculture – Agricultural Research Service, Rangeland Resources Research Unit and Northern Plains Area, Fort Collins, Colorado, United States of America
- Faculty of Agriculture and Environment, University of Sydney, Sydney, New South Wales, Australia
| | - Yolima Carrillo
- Department of Botany and Program in Ecology, University of Wyoming, Laramie, Wyoming, United States of America
- Faculty of Agriculture and Environment, University of Sydney, Sydney, New South Wales, Australia
| | - Jack A. Morgan
- United States Department of Agriculture – Agricultural Research Service, Rangeland Resources Research Unit and Northern Plains Area, Fort Collins, Colorado, United States of America
| | - Daniel R. LeCain
- United States Department of Agriculture – Agricultural Research Service, Rangeland Resources Research Unit and Northern Plains Area, Fort Collins, Colorado, United States of America
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Abstract
Rhizosphere priming is the change in decomposition of soil organic matter (SOM) caused by root activity. Rhizosphere priming plays a crucial role in soil carbon (C) dynamics and their response to global climate change. Rhizosphere priming may be affected by soil nutrient availability, but rhizosphere priming itself can also affect nutrient supply to plants. These interactive effects may be of particular relevance in understanding the sustained increase in plant growth and nutrient supply in response to a rise in atmospheric CO2 concentration. We examined how these interactions were affected by elevated CO2 in two similar semiarid grassland field studies. We found that an increase in rhizosphere priming enhanced the release of nitrogen (N) through decomposition of a larger fraction of SOM in one study, but not in the other. We postulate that rhizosphere priming may enhance N supply to plants in systems that are N limited, but that rhizosphere priming may not occur in systems that are phosphorus (P) limited. Under P limitation, rhizodeposition may be used for mobilization of P, rather than for decomposition of SOM. Therefore, with increasing atmospheric CO2 concentrations, rhizosphere priming may play a larger role in affecting C sequestration in N poor than in P poor soils.
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Affiliation(s)
- Feike A. Dijkstra
- Department of Environmental Sciences, Centre for Carbon, Water, and Food, The University of SydneyCamden, NSW, Australia
| | - Yolima Carrillo
- Department of Environmental Sciences, Centre for Carbon, Water, and Food, The University of SydneyCamden, NSW, Australia
| | - Elise Pendall
- Department of Botany and Program in Ecology, University of WyomingLaramie, WY, USA
| | - Jack A. Morgan
- Rangeland Resources Research Unit, USDA-ARSFort Collins, CO, USA
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Dijkstra FA, Morgan JA, Follett RF, Lecain DR. Climate change reduces the net sink of CH4 and N2O in a semiarid grassland. Glob Chang Biol 2013; 19:1816-1826. [PMID: 23505264 DOI: 10.1111/gcb.12182] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 02/06/2013] [Accepted: 02/17/2013] [Indexed: 06/01/2023]
Abstract
Atmospheric concentrations of methane (CH4 ) and nitrous oxide (N2 O) have increased over the last 150 years because of human activity. Soils are important sources and sinks of both potent greenhouse gases where their production and consumption are largely regulated by biological processes. Climate change could alter these processes thereby affecting both rate and direction of their exchange with the atmosphere. We examined how a rise in atmospheric CO2 and temperature affected CH4 and N2 O fluxes in a well-drained upland soil (volumetric water content ranging between 6% and 23%) in a semiarid grassland during five growing seasons. We hypothesized that responses of CH4 and N2 O fluxes to elevated CO2 and warming would be driven primarily by treatment effects on soil moisture. Previously we showed that elevated CO2 increased and warming decreased soil moisture in this grassland. We therefore expected that elevated CO2 and warming would have opposing effects on CH4 and N2 O fluxes. Methane was taken up throughout the growing season in all 5 years. A bell-shaped relationship was observed with soil moisture with highest CH4 uptake at intermediate soil moisture. Both N2 O emission and uptake occurred at our site with some years showing cumulative N2 O emission and other years showing cumulative N2 O uptake. Nitrous oxide exchange switched from net uptake to net emission with increasing soil moisture. In contrast to our hypothesis, both elevated CO2 and warming reduced the sink of CH4 and N2 O expressed in CO2 equivalents (across 5 years by 7% and 11% for elevated CO2 and warming respectively) suggesting that soil moisture changes were not solely responsible for this reduction. We conclude that in a future climate this semiarid grassland may become a smaller sink for atmospheric CH4 and N2 O expressed in CO2 -equivalents.
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Affiliation(s)
- Feike A Dijkstra
- Department of Environmental Sciences and Centre for Carbon, Water and Food, Faculty of Agriculture and Environment, The University of Sydney, Camden, NSW, 2570, Australia.
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Dijkstra FA, Pendall E, Morgan JA, Blumenthal DM, Carrillo Y, LeCain DR, Follett RF, Williams DG. Climate change alters stoichiometry of phosphorus and nitrogen in a semiarid grassland. New Phytol 2012; 196:807-815. [PMID: 23005343 DOI: 10.1111/j.1469-8137.2012.04349.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 08/22/2012] [Indexed: 05/24/2023]
Abstract
Nitrogen (N) and phosphorus (P) are essential nutrients for primary producers and decomposers in terrestrial ecosystems. Although climate change affects terrestrial N cycling with important feedbacks to plant productivity and carbon sequestration, the impacts of climate change on the relative availability of N with respect to P remain highly uncertain. In a semiarid grassland in Wyoming, USA, we studied the effects of atmospheric CO(2) enrichment (to 600 ppmv) and warming (1.5/3.0°C above ambient temperature during the day/night) on plant, microbial and available soil pools of N and P. Elevated CO(2) increased P availability to plants and microbes relative to that of N, whereas warming reduced P availability relative to N. Across years and treatments, plant N : P ratios varied between 5 and 18 and were inversely related to soil moisture. Our results indicate that soil moisture is important in controlling P supply from inorganic sources, causing reduced P relative to N availability during dry periods. Both wetter soil conditions under elevated CO(2) and drier conditions with warming can further alter N : P. Although warming may alleviate N constraints under elevated CO(2) , warming and drought can exacerbate P constraints on plant growth and microbial activity in this semiarid grassland.
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Affiliation(s)
- Feike A Dijkstra
- Department of Environmental Sciences, The University of Sydney, Eveleigh, NSW, 2015, Australia
| | - Elise Pendall
- Department of Botany and Program in Ecology, University of Wyoming, Laramie, WY, 82071, USA
| | - Jack A Morgan
- Rangeland Resources Research Unit, USDA-ARS, Fort Collins, CO, 80526, USA
| | - Dana M Blumenthal
- Rangeland Resources Research Unit, USDA-ARS, Fort Collins, CO, 80526, USA
| | - Yolima Carrillo
- Department of Environmental Sciences, The University of Sydney, Eveleigh, NSW, 2015, Australia
| | - Daniel R LeCain
- Rangeland Resources Research Unit, USDA-ARS, Fort Collins, CO, 80526, USA
| | - Ronald F Follett
- Soil, Plant, and Nutrient Research Unit, USDA-ARS, Fort Collins, CO, 80526, USA
| | - David G Williams
- Departments of Botany, Ecosystem Science and Management, Program in Ecology, University of Wyoming, Laramie, WY, 82071, USA
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Dieleman WIJ, Vicca S, Dijkstra FA, Hagedorn F, Hovenden MJ, Larsen KS, Morgan JA, Volder A, Beier C, Dukes JS, King J, Leuzinger S, Linder S, Luo Y, Oren R, De Angelis P, Tingey D, Hoosbeek MR, Janssens IA. Simple additive effects are rare: a quantitative review of plant biomass and soil process responses to combined manipulations of CO2 and temperature. Glob Chang Biol 2012; 18:2681-93. [PMID: 24501048 DOI: 10.1111/j.1365-2486.2012.02745.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 03/25/2012] [Indexed: 05/08/2023]
Abstract
In recent years, increased awareness of the potential interactions between rising atmospheric CO2 concentrations ([ CO2 ]) and temperature has illustrated the importance of multifactorial ecosystem manipulation experiments for validating Earth System models. To address the urgent need for increased understanding of responses in multifactorial experiments, this article synthesizes how ecosystem productivity and soil processes respond to combined warming and [ CO2 ] manipulation, and compares it with those obtained in single factor [ CO2 ] and temperature manipulation experiments. Across all combined elevated [ CO2 ] and warming experiments, biomass production and soil respiration were typically enhanced. Responses to the combined treatment were more similar to those in the [ CO2 ]-only treatment than to those in the warming-only treatment. In contrast to warming-only experiments, both the combined and the [ CO2 ]-only treatments elicited larger stimulation of fine root biomass than of aboveground biomass, consistently stimulated soil respiration, and decreased foliar nitrogen (N) concentration. Nonetheless, mineral N availability declined less in the combined treatment than in the [ CO2 ]-only treatment, possibly due to the warming-induced acceleration of decomposition, implying that progressive nitrogen limitation (PNL) may not occur as commonly as anticipated from single factor [ CO2 ] treatment studies. Responses of total plant biomass, especially of aboveground biomass, revealed antagonistic interactions between elevated [ CO2 ] and warming, i.e. the response to the combined treatment was usually less-than-additive. This implies that productivity projections might be overestimated when models are parameterized based on single factor responses. Our results highlight the need for more (and especially more long-term) multifactor manipulation experiments. Because single factor CO2 responses often dominated over warming responses in the combined treatments, our results also suggest that projected responses to future global warming in Earth System models should not be parameterized using single factor warming experiments.
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Affiliation(s)
- Wouter I J Dieleman
- Research Group of Plant and Vegetation Ecology, Department of Biology, University of Antwerp, Wilrijk, B-2610, Belgium; School of Earth and Environmental Sciences, Faculty of Science and Engineering, James Cook University, Smithfield, 4878, QLD, Australia
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Carrillo Y, Dijkstra FA, Pendall E, Morgan JA, Blumenthal DM. Controls over Soil Nitrogen Pools in a Semiarid Grassland Under Elevated CO2 and Warming. Ecosystems 2012. [DOI: 10.1007/s10021-012-9544-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Dijkstra FA, Augustine DJ, Brewer P, von Fischer JC. Nitrogen cycling and water pulses in semiarid grasslands: are microbial and plant processes temporally asynchronous? Oecologia 2012; 170:799-808. [PMID: 22555358 DOI: 10.1007/s00442-012-2336-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Accepted: 04/12/2012] [Indexed: 11/24/2022]
Abstract
Precipitation pulses in arid ecosystems can lead to temporal asynchrony in microbial and plant processing of nitrogen (N) during drying/wetting cycles causing increased N loss. In contrast, more consistent availability of soil moisture in mesic ecosystems can synchronize microbial and plant processes during the growing season, thus minimizing N loss. We tested whether microbial N cycling is asynchronous with plant N uptake in a semiarid grassland. Using (15)N tracers, we compared rates of N cycling by microbes and N uptake by plants after water pulses of 1 and 2 cm to rates in control plots without a water pulse. Microbial N immobilization, gross N mineralization, and nitrification dramatically increased 1-3 days after the water pulses, with greatest responses after the 2-cm pulse. In contrast, plant N uptake increased more after the 1-cm than after the 2-cm pulse. Both microbial and plant responses reverted to control levels within 10 days, indicating that both microbial and plant responses were short lived. Thus, microbial and plant processes were temporally synchronous following a water pulse in this semiarid grassland, but the magnitude of the pulse substantially influenced whether plants or microbes were more effective in acquiring N. Furthermore, N loss increased after both small and large water pulses (as shown by a decrease in total (15)N recovery), indicating that changes in precipitation event sizes with future climate change could exacerbate N losses from semiarid ecosystems.
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Affiliation(s)
- Feike A Dijkstra
- Department of Environmental Sciences, The University of Sydney, Level 4, Biomedical Building, 1 Central Avenue, Eveleigh, NSW, 2015, Australia.
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Dijkstra FA, Morgan JA, von Fischer JC, Follett RF. Elevated CO2and warming effects on CH4uptake in a semiarid grassland below optimum soil moisture. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jg001288] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Augustine DJ, Dijkstra FA, William Hamilton Iii E, Morgan JA. Rhizosphere interactions, carbon allocation, and nitrogen acquisition of two perennial North American grasses in response to defoliation and elevated atmospheric CO2. Oecologia 2010; 165:755-70. [PMID: 21113625 DOI: 10.1007/s00442-010-1845-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Accepted: 11/04/2010] [Indexed: 10/18/2022]
Abstract
Carbon allocation and N acquisition by plants following defoliation may be linked through plant-microbe interactions in the rhizosphere. Plant C allocation patterns and rhizosphere interactions can also be affected by rising atmospheric CO(2) concentrations, which in turn could influence plant and microbial responses to defoliation. We studied two widespread perennial grasses native to rangelands of western North America to test whether (1) defoliation-induced enhancement of rhizodeposition would stimulate rhizosphere N availability and plant N uptake, and (2) defoliation-induced enhancement of rhizodeposition, and associated effects on soil N availability, would increase under elevated CO(2). Both species were grown at ambient (400 μL L(-1)) and elevated (780 μL L(-1)) atmospheric [CO(2)] under water-limiting conditions. Plant, soil and microbial responses were measured 1 and 8 days after a defoliation treatment. Contrary to our hypotheses, we found that defoliation and elevated CO(2) both reduced carbon inputs to the rhizosphere of Bouteloua gracilis (C(4)) and Pascopyrum smithii (C(3)). However, both species also increased N allocation to shoots of defoliated versus non-defoliated plants 8 days after treatment. This response was greatest for P. smithii, and was associated with negative defoliation effects on root biomass and N content and reduced allocation of post-defoliation assimilate to roots. In contrast, B. gracilis increased allocation of post-defoliation assimilate to roots, and did not exhibit defoliation-induced reductions in root biomass or N content. Our findings highlight key differences between these species in how post-defoliation C allocation to roots versus shoots is linked to shoot N yield, but indicate that defoliation-induced enhancement of shoot N concentration and N yield is not mediated by increased C allocation to the rhizosphere.
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Affiliation(s)
- David J Augustine
- Agricultural Research Service, Rangeland Resources Research Unit, USDA, 1701 Centre Ave, Fort Collins, CO 80526, USA.
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Dijkstra FA, Blumenthal D, Morgan JA, Pendall E, Carrillo Y, Follett RF. Contrasting effects of elevated CO2 and warming on nitrogen cycling in a semiarid grassland. New Phytol 2010; 187:426-437. [PMID: 20487311 DOI: 10.1111/j.1469-8137.2010.03293.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
*Simulation models indicate that the nitrogen (N) cycle plays a key role in how other ecosystem processes such as plant productivity and carbon (C) sequestration respond to elevated CO(2) and warming. However, combined effects of elevated CO(2) and warming on N cycling have rarely been tested in the field. *Here, we studied N cycling under ambient and elevated CO(2) concentrations (600 micromol mol(-1)), and ambient and elevated temperature (1.5 : 3.0 degrees C warmer day:night) in a full factorial semiarid grassland field experiment in Wyoming, USA. We measured soil inorganic N, plant and microbial N pool sizes and NO(3)(-) uptake (using a (15)N tracer). *Soil inorganic N significantly decreased under elevated CO(2), probably because of increased microbial N immobilization, while soil inorganic N and plant N pool sizes significantly increased with warming, probably because of increased N supply. We observed no CO(2 )x warming interaction effects on soil inorganic N, N pool sizes or NO(3)(-) uptake in plants and microbes. *Our results indicate a more closed N cycle under elevated CO(2) and a more open N cycle with warming, which could affect long-term N retention, plant productivity, and C sequestration in this semiarid grassland.
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Affiliation(s)
- Feike A Dijkstra
- Rangeland Resources Research Unit, USDA-ARS, Crops Research Laboratory, 1701 Centre Ave, Fort Collins, CO 80526, USA
| | - Dana Blumenthal
- Rangeland Resources Research Unit, USDA-ARS, Crops Research Laboratory, 1701 Centre Ave, Fort Collins, CO 80526, USA
| | - Jack A Morgan
- Rangeland Resources Research Unit, USDA-ARS, Crops Research Laboratory, 1701 Centre Ave, Fort Collins, CO 80526, USA
| | - Elise Pendall
- Department of Botany and Program in Ecology, University of Wyoming, Laramie, WY 82071, USA
| | - Yolima Carrillo
- Department of Botany and Program in Ecology, University of Wyoming, Laramie, WY 82071, USA
| | - Ronald F Follett
- Soil, Plant, and Nutrient Research Unit, USDA-ARS, 2150 Centre Ave, Fort Collins, CO 80526, USA
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Dijkstra FA, Blumenthal D, Morgan JA, LeCain DR, Follett RF. Elevated CO2 effects on semi-arid grassland plants in relation to water availability and competition. Funct Ecol 2010. [DOI: 10.1111/j.1365-2435.2010.01717.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
Many aspects of nitrogen (N) cycling in terrestrial ecosystems remain poorly understood. Progress in studying N cycling has been hindered by a lack of effective measurements that integrate processes such as denitrification, competition for N between plants and microbes, and soil organic matter (SOM) decomposition over large time scales (years rather than hours or days). Here I show how long-term measurements of 15N in plants, microbes, and soil after a one-time addition of 15N ("labeled" N) can provide powerful information about long-term N dynamics in a semiarid grassland. I develop a simple dynamic model and show that labeled-N fractions in plant and microbial-N pools (expressed as a fraction of total N in each pool) can change long after 15N application (> or = 5 years). These 15N dynamics are closely tied to the turnover times of the different N pools. The model accurately simulated the labeled-N fractions in aboveground biomass measured annually during five years after addition of 15N to a semiarid grassland. I also tested the sensitivity of five different processes on labeled-N fractions in aboveground plant biomass. Changing plant/microbial competition for N had very little effect on the labeled-N fraction in aboveground biomass in the short and long-term. Changing microbial activity (N mineralization and immobilization), N loss, or N resorption/re-translocation by plants affected the labeled-N fraction in the short-term, but not in the long-term. Large long-term effects on the labeled-N fraction in aboveground biomass could only be established by changing the size of the active soil-N pool. Therefore, the significantly greater long-term decline in the labeled-N fraction in aboveground biomass observed under elevated CO2 in this grassland system could have resulted from an increased active soil-N pool under elevated CO2 (i.e., destabilization of soil organic matter that was relatively recalcitrant under ambient CO2 conditions). I conclude that short- and long-term labeled-N fractions in plant biomass after a 15N pulse are sensitive to processes such as N mineralization and immobilization, N loss, and soil organic matter (de-)stabilization. Modeling these fractions provides a useful tool to better understand N cycling in terrestrial ecosystems.
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Affiliation(s)
- Feike A Dijkstra
- USDA-ARS, Rangeland Resources Research Unit, 1701 Centre Ave, Fort Collins, Colorado 80526, USA.
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Abstract
Decomposition of soil organic carbon (SOC) is the main process governing the release of CO(2) into the atmosphere from terrestrial systems. Although the importance of soil-root interactions for SOC decomposition has increasingly been recognized, their long-term effect on SOC decomposition remains poorly understood. Here we provide experimental evidence for a rhizosphere priming effect, in which interactions between soil and tree roots substantially accelerate SOC decomposition. In a 395-day greenhouse study with Ponderosa pine and Fremont cottonwood trees grown in three different soils, SOC decomposition in the planted treatments was significantly greater (up to 225%) than in soil incubations alone. This rhizosphere priming effect persisted throughout the experiment, until well after initial soil disturbance, and increased with a greater amount of root-derived SOC formed during the experiment. Loss of old SOC was greater than the formation of new C, suggesting that increased C inputs from roots could result in net soil C loss.
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Affiliation(s)
- Feike A Dijkstra
- Department of Environmental Studies, University of California, Santa Cruz, CA 95064, USA.
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Abstract
In nitrogen (N)-limited systems, the potential to sequester carbon depends on the balance between N inputs and losses as well as on how efficiently N is used, yet little is known about responses of these processes to changes in plant species richness, atmospheric CO2 concentration ([CO2]), and N deposition. We examined how plant species richness (1 or 16 species), elevated [CO2] (ambient or 560 ppm), and inorganic N addition (0 or 4 g x m(-2) x yr(-1)) affected ecosystem N losses, specifically leaching of dissolved inorganic N (DIN) and organic N (DON) in a grassland field experiment in Minnesota, USA. We observed greater DIN leaching below 60 cm soil depth in the monoculture plots (on average 1.8 and 3.1 g N x m(-2) x yr(-1) for ambient N and N-fertilized plots respectively) than in the 16-species plots (0.2 g N x m(-2) x yr(-1) for both ambient N and N-fertilized plots), particularly when inorganic N was added. Most likely, loss of complementary resource use and reduced biological N demand in the monoculture plots caused the increase in DIN leaching relative to the high-diversity plots. Elevated [CO2] reduced DIN concentrations under conditions when DIN concentrations were high (i.e., in N-fertilized and monoculture plots). Contrary to the results for DIN, DON leaching was greater in the 16-species plots than in the monoculture plots (on average 0.4 g N x m(-2) x yr(-1) in 16-species plots and 0.2 g N x m(-2) x yr(-1) in monoculture plots). In fact, DON dominated N leaching in the 16-species plots (64% of total N leaching as DON), suggesting that, even with high biological demand for N, substantial amounts of N can be lost as DON. We found no significant main effects of elevated [CO2] on DIN or DON leaching; however, elevated [CO2] reduced the positive effect of inorganic N addition on DON leaching, especially during the second year of observation. Our results suggest that plant species richness, elevated [CO2], and N deposition alter DIN loss primarily through changes in biological N demand. DON losses can be as large as DIN loss but are more sensitive to organic matter production and turnover.
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Affiliation(s)
- Feike A Dijkstra
- Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, Minnesota 55108, USA.
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