1
|
Yi B, Lu C, Huang W, Yu W, Yang J, Howe A, Weintraub-Leff SR, Hall SJ. Resolving the influence of lignin on soil organic matter decomposition with mechanistic models and continental-scale data. Glob Chang Biol 2023; 29:5968-5980. [PMID: 37448171 DOI: 10.1111/gcb.16875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 06/05/2023] [Indexed: 07/15/2023]
Abstract
Confidence in model estimates of soil CO2 flux depends on assumptions regarding fundamental mechanisms that control the decomposition of litter and soil organic carbon (SOC). Multiple hypotheses have been proposed to explain the role of lignin, an abundant and complex biopolymer that may limit decomposition. We tested competing mechanisms using data-model fusion with modified versions of the CN-SIM model and a 571-day laboratory incubation dataset where decomposition of litter, lignin, and SOC was measured across 80 soil samples from the National Ecological Observatory Network. We found that lignin decomposition consistently decreased over time in 65 samples, whereas in the other 15 samples, lignin decomposition subsequently increased. These "lagged-peak" samples can be predicted by low soil pH, high extractable Mn, and fungal community composition as measured by ITS PC2 (the second principal component of an ordination of fungal ITS amplicon sequences). The highest-performing model incorporated soil biogeochemical factors and daily dynamics of substrate availability (labile bulk litter:lignin) that jointly represented two hypotheses (C substrate limitation and co-metabolism) previously thought to influence lignin decomposition. In contrast, models representing either hypothesis alone were biased and underestimated cumulative decomposition. Our findings reconcile competing hypotheses of lignin decomposition and suggest the need to precisely represent the role of lignin and consider soil metal and fungal characteristics to accurately estimate decomposition in Earth-system models.
Collapse
Affiliation(s)
- Bo Yi
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - Chaoqun Lu
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - Wenjuan Huang
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - Wenjuan Yu
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - Jihoon Yang
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, Iowa, USA
| | - Adina Howe
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, Iowa, USA
| | | | - Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
- Department of Plant and Agroecosystem Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA
| |
Collapse
|
2
|
Hartfiel LM, Hoover NL, Hall SJ, Isenhart TM, Gomes CL, Soupir ML. Extreme low-flow conditions in a dual-chamber denitrification bioreactor contribute to pollution swapping with low landscape-scale impact. Sci Total Environ 2023; 877:162837. [PMID: 36924958 DOI: 10.1016/j.scitotenv.2023.162837] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/17/2023] [Accepted: 03/09/2023] [Indexed: 05/06/2023]
Abstract
Denitrification bioreactors are an effective edge-of-field conservation practice for nitrate (NO3) reduction from subsurface drainage. However, these systems may produce other pollutants and greenhouse gases during NO3 removal. Here a dual-chamber woodchip bioreactor system experiencing extreme low-flow conditions was monitored for its spatiotemporal NO3 and total organic carbon dynamics in the drainage water. Near complete removal of NO3 was observed in both bioreactor chambers in the first two years of monitoring (2019-2020) and in the third year of monitoring in chamber A, with significant (p < 0.01) reduction of the NO3-N each year in both chambers with 8.6-11.4 mg NO3-N L-1 removed on average. Based on the NO3 removal observed, spatial monitoring of sulfate (SO4), dissolved methane (CH4), and dissolved nitrous oxide (N2O) gases was added in the third year of monitoring (2021). In 2021, chambers A and B had median hydraulic residence times (HRTs) of 64 h and 39 h, respectively, due to varying elevations of the chambers, with drought conditions making the differences more pronounced. In 2021, significant production of dissolved CH4 was observed at rates of 0.54 g CH4-C m-3 d-1 and 0.07 g CH4-C m-3 d-1 in chambers A and B, respectively. In chamber A, significant removal (p < 0.01) of SO4 (0.23 g SO4 m-3 d-1) and dissolved N2O (0.21 mg N2O-N m-2 d-1) were observed, whereas chamber B produced N2O (0.36 mg N2O-N m-2 d-1). Considering the carbon dioxide equivalents (CO2e) on an annual basis, chamber A had loads (~12,000 kg CO2e ha-1 y-1) greater than comparable poorly drained agricultural soils; however, the landscape-scale impact was small (<1 % change in CO2e) when expressed over the drainage area treated by the bioreactor. Under low-flow conditions, pollution swapping in woodchip bioreactors can be reduced at HRTs <50 h and NO3 concentrations >2 mg N L-1.
Collapse
Affiliation(s)
- Lindsey M Hartfiel
- UW Discovery Farms, University of Wisconsin-Madison, Division of Extension, Madison, WI, United States.
| | - Natasha L Hoover
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA, United States
| | - Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, United States
| | - Thomas M Isenhart
- Department of Natural Resource Ecology and Management, Iowa State University, Ames, IA, United States
| | - Carmen L Gomes
- Department of Mechanical Engineering, Iowa State University, Ames, IA, United States
| | - Michelle L Soupir
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA, United States
| |
Collapse
|
3
|
Hall SJ, Tenesaca CG, Lawrence NC, Green DIS, Helmers MJ, Crumpton WG, Heaton EA, VanLoocke A. Poorly drained depressions can be hotspots of nutrient leaching from agricultural soils. J Environ Qual 2023; 52:678-690. [PMID: 36763775 DOI: 10.1002/jeq2.20461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 01/27/2023] [Indexed: 05/06/2023]
Abstract
Much of the US Corn Belt has been drained with subsurface tile to improve crop production, yet poorly drained depressions often still flood intermittently, suppressing crop growth. Impacts of depressions on field-scale nutrient leaching are unclear. Poor drainage might promote denitrification and physicochemical retention of phosphorus (P), but ample availability of water and nutrients might exacerbate nutrient leaching from cropped depressions. We monitored nitrate, ammonium, and reactive P leaching across multiple depression-to-upland transects in north-central Iowa, using resin lysimeters buried and retrieved on an annual basis. Crops included conventional corn/soybean (Zea mays/Glycine max) rotations measured at fields with and without a winter rye (Secale cereale) cover crop, as well as juvenile miscanthus (Miscanthus × giganteus), a perennial grass. Leaching of nitrogen (N) and P was greater in depressions than in uplands for most transects and years. The median difference in nutrient leaching between paired depressions and uplands was 56 kg N ha-1 year-1 for nitrate (p = 0.0008), 0.6 kg N ha-1 year-1 for ammonium (p = 0.03), and 2.4 kg P ha-1 year-1 for reactive P (p = 0.006). Transects managed with a cover crop or miscanthus tended to have a smaller median difference in nitrate (but not ammonium or P) leaching between depressions and uplands. Cropped depressions may be disproportionate sources of N and P to downstream waters despite their generally poor drainage characteristics, and targeted management with cover crops or perennials might partially mitigate these impacts for N, but not necessarily for P.
Collapse
Affiliation(s)
- Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - Carlos G Tenesaca
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - Nathaniel C Lawrence
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - David I S Green
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - Matthew J Helmers
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, Iowa, USA
| | - William G Crumpton
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - Emily A Heaton
- Department of Agronomy, Iowa State University, Ames, Iowa, USA
- Department of Crop Sciences, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
| | - Andy VanLoocke
- Department of Agronomy, Iowa State University, Ames, Iowa, USA
| |
Collapse
|
4
|
Huang W, Yu W, Yi B, Raman E, Yang J, Hammel KE, Timokhin VI, Lu C, Howe A, Weintraub-Leff SR, Hall SJ. Contrasting geochemical and fungal controls on decomposition of lignin and soil carbon at continental scale. Nat Commun 2023; 14:2227. [PMID: 37076534 PMCID: PMC10115774 DOI: 10.1038/s41467-023-37862-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 04/03/2023] [Indexed: 04/21/2023] Open
Abstract
Lignin is an abundant and complex plant polymer that may limit litter decomposition, yet lignin is sometimes a minor constituent of soil organic carbon (SOC). Accounting for diversity in soil characteristics might reconcile this apparent contradiction. Tracking decomposition of a lignin/litter mixture and SOC across different North American mineral soils using lab and field incubations, here we show that cumulative lignin decomposition varies 18-fold among soils and is strongly correlated with bulk litter decomposition, but not SOC decomposition. Climate legacy predicts decomposition in the lab, and impacts of nitrogen availability are minor compared with geochemical and microbial properties. Lignin decomposition increases with some metals and fungal taxa, whereas SOC decomposition decreases with metals and is weakly related with fungi. Decoupling of lignin and SOC decomposition and their contrasting biogeochemical drivers indicate that lignin is not necessarily a bottleneck for SOC decomposition and can explain variable contributions of lignin to SOC among ecosystems.
Collapse
Affiliation(s)
- Wenjuan Huang
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
| | - Wenjuan Yu
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA.
| | - Bo Yi
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
| | - Erik Raman
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA, USA
| | - Jihoon Yang
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA, USA
| | - Kenneth E Hammel
- U.S. Forest Products Laboratory, Madison, WI, USA
- Department of Bacteriology, University of Wisconsin, Madison, WI, USA
| | - Vitaliy I Timokhin
- Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, WI, USA
| | - Chaoqun Lu
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
| | - Adina Howe
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA, USA
| | | | - Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
| |
Collapse
|
5
|
Hall SJ, Huang W, Napieralski SA, Roden E. Shared Microbial Taxa Respond Predictably to Cyclic Time-Varying Oxygen Limitation in Two Disparate Soils. Front Microbiol 2022; 13:866828. [PMID: 35722278 PMCID: PMC9203030 DOI: 10.3389/fmicb.2022.866828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 01/31/2022] [Accepted: 05/16/2022] [Indexed: 11/27/2022] Open
Abstract
Periodic oxygen (O2) limitation in humid terrestrial soils likely influences microbial composition, but whether communities share similar responses in disparate environments remains unclear. To test if specific microbial taxa share consistent responses to anoxia in radically different soils, we incubated a rainforest Oxisol and cropland Mollisol under cyclic, time-varying anoxic/oxic cycles in the laboratory. Both soils are known to experience anoxic periods of days to weeks under field conditions; our incubation treatments consisted of anoxic periods of 0, 2, 4, 8, or 12 d followed by 4 d of oxic conditions, repeated for a total of 384 d. Taxa measured by 16S rRNA gene sequences after 48 d and 384 d of experimental treatments varied strongly with increasing anoxic period duration, and responses to anoxia often differed between soils at multiple taxonomic levels. Only 19% of the 30,356 operational taxonomic units (OTUs) occurred in both soils, and most OTUs did not respond consistently to O2 treatments. However, the OTUs present in both soils were disproportionally abundant, comprising 50% of sequences, and they often had a similar response to anoxic period duration in both soils (p < 0.0001). Overall, 67 OTUs, 36 families, 15 orders, 10 classes, and two phyla had significant and directionally consistent (positive or negative) responses to anoxic period duration in both soils. Prominent OTUs and taxonomic groups increasing with anoxic period duration in both soils included actinomycetes (Micromonosporaceae), numerous Ruminococcaceae, possible metal reducers (Anaeromyxobacter) or oxidizers (Candidatus Koribacter), methanogens (Methanomicrobia), and methanotrophs (Methylocystaceae). OTUs decreasing with anoxic duration in both soils included nitrifiers (Nitrospira) and ubiquitous unidentified Bradyrhizobiaceae and Micromonosporaceae. Even within the same genus, different OTUs occasionally showed strong positive or negative responses to anoxic duration (e.g., Dactylosporangium in the Actinobacteria), highlighting a potential for adaptation or niche partitioning in variable-O2 environments. Overall, brief anoxic periods impacted the abundance of certain microbial taxa in predictable ways, suggesting that microbial community data may partially reflect and integrate spatiotemporal differences in O2 availability within and among soils.
Collapse
Affiliation(s)
- Steven J. Hall
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA, United States
- *Correspondence: Steven J. Hall,
| | - Wenjuan Huang
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA, United States
| | | | - Eric Roden
- Department of Geoscience, University of Wisconsin-Madison, Madison, WI, United States
| |
Collapse
|
6
|
Holden KG, Hedrick AR, Gangloff EJ, Hall SJ, Bronikowski AM. Temperature-dependence of metabolism and fuel selection from cells to whole organisms. J Exp Zool A Ecol Integr Physiol 2022; 337:199-205. [PMID: 34855309 DOI: 10.1002/jez.2564] [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: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 06/13/2023]
Abstract
Temperature affects nearly every aspect of how organisms interact with and are constrained by their environment. Measures of organismal energetics, such as metabolic rate, are highly temperature-dependent and governed through temperature effects on rates of biochemical reactions. Characterizing the relationships among levels of biological organization can lend insight into how temperature affects whole-organism function. We tested the temperature dependence of cellular oxygen consumption and its relationship to whole-animal metabolic rate in garter snakes (Thamnophis elegans). Additionally, we tested whether thermal responses were linked to shifts in the fuel source oxidized to support metabolism with the use of carbon stable isotopes. Our results demonstrate temperature dependence of metabolic rates across levels of biological organization. Cellular (basal, adenosine triphosphate-linked) and whole-animal rates of respiration increased with temperature but were not correlated within or among individuals, suggesting that variation in whole-animal metabolic rates is not due simply to variation at the cellular level, but rather other interacting factors across scales of biological organization. Counter to trends observed during fasting, elevated temperature did not alter fuel selection (i.e., natural-abundance stable carbon isotope composition in breath, δ13 Cbreath ). This consistency suggests the maintenance and oxidation of a single fuel source supporting metabolism across a broad range of metabolic demands.
Collapse
Affiliation(s)
- Kaitlyn G Holden
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - Ashley R Hedrick
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - Eric J Gangloff
- Department of Zoology, Ohio Wesleyan University, Delaware, Ohio, USA
| | - Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - Anne M Bronikowski
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| |
Collapse
|
7
|
Huang W, Wang K, Ye C, Hockaday WC, Wang G, Hall SJ. High carbon losses from oxygen-limited soils challenge biogeochemical theory and model assumptions. Glob Chang Biol 2021; 27:6166-6180. [PMID: 34464997 DOI: 10.1111/gcb.15867] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 07/28/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
Oxygen (O2 ) limitation contributes to persistence of large carbon (C) stocks in saturated soils. However, many soils experience spatiotemporal O2 fluctuations impacted by climate and land-use change, and O2 -mediated climate feedbacks from soil greenhouse gas emissions remain poorly constrained. Current theory and models posit that anoxia uniformly suppresses carbon (C) decomposition. Here we show that periodic anoxia may sustain or even stimulate decomposition over weeks to months in two disparate soils by increasing turnover and/or size of fast-cycling C pools relative to static oxic conditions, and by sustaining decomposition of reduced organic molecules. Cumulative C losses did not decrease consistently as cumulative O2 exposure decreased. After >1 year, soils anoxic for 75% of the time had similar C losses as the oxic control but nearly threefold greater climate impact on a CO2 -equivalent basis (20-year timescale) due to high methane (CH4 ) emission. A mechanistic model incorporating current theory closely reproduced oxic control results but systematically underestimated C losses under O2 fluctuations. Using a model-experiment integration (ModEx) approach, we found that models were improved by varying microbial maintenance respiration and the fraction of CH4 production in total C mineralization as a function of O2 availability. Consistent with thermodynamic expectations, the calibrated models predicted lower microbial C-use efficiency with increasing anoxic duration in one soil; in the other soil, dynamic organo-mineral interactions implied by our empirical data but not represented in the model may have obscured this relationship. In both soils, the updated model was better able to capture transient spikes in C mineralization that occurred following anoxic-oxic transitions, where decomposition from the fluctuating-O2 treatments greatly exceeded the control. Overall, our data-model comparison indicates that incorporating emergent biogeochemical properties of soil O2 variability will be critical for effectively modeling C-climate feedbacks in humid ecosystems.
Collapse
Affiliation(s)
- Wenjuan Huang
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - Kefeng Wang
- College of Life Science, Northwest University, Xi'an, China
| | - Chenglong Ye
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
- Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | | | - Gangsheng Wang
- Institute for Water-Carbon Cycles and Carbon Neutrality, and State Key Laboratory of Water Resources and Hydropower Engineering Sciences, Wuhan University, Wuhan, China
| | - Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, USA
| |
Collapse
|
8
|
Lawrence NC, Tenesaca CG, VanLoocke A, Hall SJ. Nitrous oxide emissions from agricultural soils challenge climate sustainability in the US Corn Belt. Proc Natl Acad Sci U S A 2021; 118:e2112108118. [PMID: 34750266 PMCID: PMC8694048 DOI: 10.1073/pnas.2112108118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2021] [Indexed: 11/18/2022] Open
Abstract
Agricultural landscapes are the largest source of anthropogenic nitrous oxide (N2O) emissions, but their specific sources and magnitudes remain contested. In the US Corn Belt, a globally important N2O source, in-field soil emissions were reportedly too small to account for N2O measured in the regional atmosphere, and disproportionately high N2O emissions from intermittent streams have been invoked to explain the discrepancy. We collected 3 y of high-frequency (4-h) measurements across a topographic gradient, including a very poorly drained (intermittently flooded) depression and adjacent upland soils. Mean annual N2O emissions from this corn-soybean rotation (7.8 kg of N2O-N ha-1⋅y-1) were similar to a previous regional top-down estimate, regardless of landscape position. Synthesizing other Corn Belt studies, we found mean emissions of 5.6 kg of N2O-N ha-1⋅y-1 from soils with similar drainage to our transect (moderately well-drained to very poorly drained), which collectively comprise 60% of corn-soybean-cultivated soils. In contrast, strictly well-drained soils averaged only 2.3 kg of N2O-N ha-1⋅y-1 Our results imply that in-field N2O emissions from soils with moderately to severely impaired drainage are similar to regional mean values and that N2O emissions from well-drained soils are not representative of the broader Corn Belt. On the basis of carbon dioxide equivalents, the warming effect of direct N2O emissions from our transect was twofold greater than optimistic soil carbon gains achievable from agricultural practice changes. Despite the recent focus on soil carbon sequestration, addressing N2O emissions from wet Corn Belt soils may have greater leverage in achieving climate sustainability.
Collapse
Affiliation(s)
- Nathaniel C Lawrence
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011
| | - Carlos G Tenesaca
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011
| | - Andy VanLoocke
- Department of Agronomy, Iowa State University, Ames, IA 50011
| | - Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011;
| |
Collapse
|
9
|
Waring BG, Sulman BN, Reed S, Smith AP, Averill C, Creamer CA, Cusack DF, Hall SJ, Jastrow JD, Jilling A, Kemner KM, Kleber M, Liu XJA, Pett-Ridge J, Schulz M. Response to "Connectivity and pore accessibility in models of soil carbon cycling". Glob Chang Biol 2021; 27:e15-e16. [PMID: 34407279 DOI: 10.1111/gcb.15850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Affiliation(s)
- Bonnie G Waring
- Grantham Institute on Climate and the Environment, Imperial College London, London, UK
| | - Benjamin N Sulman
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Sasha Reed
- Southwest Biological Science Center, U.S. Geological Survey, Moab, Utah, USA
| | - A Peyton Smith
- Department of Soil and Crop Sciences, Texas A&M University, College Station, Texas, USA
| | - Colin Averill
- Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland
| | | | - Daniela F Cusack
- Department of Ecosystem Science and Sustainability, Warner College of Natural Resources, Colorado State University, Fort Collins, Colorado, USA
| | - Steven J Hall
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, Iowa, USA
| | - Julie D Jastrow
- Environmental Science Division, Argonne National Laboratory, Lemont, Illinois, USA
| | - Andrea Jilling
- Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Kenneth M Kemner
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois, USA
| | - Markus Kleber
- Department of Crop and Soil Science, Oregon State University, Corvallis, Oregon, USA
| | - Xiao-Jun Allen Liu
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - Jennifer Pett-Ridge
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
| | | |
Collapse
|
10
|
Waring BG, Sulman BN, Reed S, Smith AP, Averill C, Creamer CA, Cusack DF, Hall SJ, Jastrow JD, Jilling A, Kemner KM, Kleber M, Allen Liu XJ, Pett-Ridge J, Schulz M. Response to 'Stochastic and deterministic interpretation of pool models'. Glob Chang Biol 2021; 27:e11-e12. [PMID: 33660887 DOI: 10.1111/gcb.15580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 02/25/2021] [Indexed: 06/12/2023]
Affiliation(s)
- Bonnie G Waring
- Grantham Institute on Climate and the Environment, Imperial College London, London, UK
| | - Benjamin N Sulman
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Sasha Reed
- U.S. Geological Survey, Southwest Biological Science Center, Moab, UT, USA
| | - A Peyton Smith
- Department of Soil and Crop Sciences, Texas A&M University, College Station, TX, USA
| | - Colin Averill
- Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland
| | | | - Daniela F Cusack
- Department of Ecosystem Science and Sustainability, Warner College of Natural Resources, Colorado State University, Fort Collins, CO, USA
| | - Steven J Hall
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA, USA
| | - Julie D Jastrow
- Environmental Science Division, Argonne National Laboratory, Lemont, IL, USA
| | - Andrea Jilling
- Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK, USA
| | - Kenneth M Kemner
- Biosciences Division, Argonne National Laboratory, Lemont, IL, USA
| | - Markus Kleber
- Department of Crop and Soil Science, Oregon State University, Corvallis, OR, USA
| | - Xiao-Jun Allen Liu
- Department of Microbiology, University of Massachusetts, Amherst, MA, USA
| | - Jennifer Pett-Ridge
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | | |
Collapse
|
11
|
Bel J, Legout A, Saint-André L, Hall SJ, Löfgren S, Laclau JP, van der Heijden G. Author Correction: Conventional analysis methods underestimate the plant-available pools of calcium, magnesium and potassium in forest soils. Sci Rep 2021; 11:4322. [PMID: 33594099 PMCID: PMC7886882 DOI: 10.1038/s41598-021-81982-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Collapse
Affiliation(s)
- Jérémie Bel
- INRAE Grand-EST Nancy, UR 1138 Biogéochimie Des Ecosystèmes Forestiers, Route d'Amance, 54280, Champenoux, France
| | - Arnaud Legout
- INRAE Grand-EST Nancy, UR 1138 Biogéochimie Des Ecosystèmes Forestiers, Route d'Amance, 54280, Champenoux, France
| | - Laurent Saint-André
- INRAE Grand-EST Nancy, UR 1138 Biogéochimie Des Ecosystèmes Forestiers, Route d'Amance, 54280, Champenoux, France
| | - Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, 251 Bessey Hall, Ames, IA, 50011, USA
| | - Stefan Löfgren
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, P.O. Box 7050, 750 07, Uppsala, Sweden
| | - Jean-Paul Laclau
- CIRAD, UMR 210 ecologie fonctionnelle et biogéochimie des sols et des agro-écosystèmes, Campus SupAgro, Bâtiment 12-2 place Viala, 34060, Montpellier, Cedex 2, France
| | - Gregory van der Heijden
- INRAE Grand-EST Nancy, UR 1138 Biogéochimie Des Ecosystèmes Forestiers, Route d'Amance, 54280, Champenoux, France.
| |
Collapse
|
12
|
Waring BG, Sulman BN, Reed S, Smith AP, Averill C, Creamer CA, Cusack DF, Hall SJ, Jastrow JD, Jilling A, Kemner KM, Kleber M, Liu XJA, Pett-Ridge J, Schulz M. From pools to flow: The PROMISE framework for new insights on soil carbon cycling in a changing world. Glob Chang Biol 2020; 26:6631-6643. [PMID: 33064359 DOI: 10.1111/gcb.15365] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Accepted: 09/11/2020] [Indexed: 05/02/2023]
Abstract
Soils represent the largest terrestrial reservoir of organic carbon, and the balance between soil organic carbon (SOC) formation and loss will drive powerful carbon-climate feedbacks over the coming century. To date, efforts to predict SOC dynamics have rested on pool-based models, which assume classes of SOC with internally homogenous physicochemical properties. However, emerging evidence suggests that soil carbon turnover is not dominantly controlled by the chemistry of carbon inputs, but rather by restrictions on microbial access to organic matter in the spatially heterogeneous soil environment. The dynamic processes that control the physicochemical protection of carbon translate poorly to pool-based SOC models; as a result, we are challenged to mechanistically predict how environmental change will impact movement of carbon between soils and the atmosphere. Here, we propose a novel conceptual framework to explore controls on belowground carbon cycling: Probabilistic Representation of Organic Matter Interactions within the Soil Environment (PROMISE). In contrast to traditional model frameworks, PROMISE does not attempt to define carbon pools united by common thermodynamic or functional attributes. Rather, the PROMISE concept considers how SOC cycling rates are governed by the stochastic processes that influence the proximity between microbial decomposers and organic matter, with emphasis on their physical location in the soil matrix. We illustrate the applications of this framework with a new biogeochemical simulation model that traces the fate of individual carbon atoms as they interact with their environment, undergoing biochemical transformations and moving through the soil pore space. We also discuss how the PROMISE framework reshapes dialogue around issues related to SOC management in a changing world. We intend the PROMISE framework to spur the development of new hypotheses, analytical tools, and model structures across disciplines that will illuminate mechanistic controls on the flow of carbon between plant, soil, and atmospheric pools.
Collapse
Affiliation(s)
- Bonnie G Waring
- Department of Biology and Ecology Center, Utah State University, Logan, UT, USA
| | - Benjamin N Sulman
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Sasha Reed
- U.S. Geological Survey, Southwest Biological Science Center, Moab, UT, USA
| | - A Peyton Smith
- Department of Soil and Crop Sciences, Texas A&M University, College Station, TX, USA
| | - Colin Averill
- Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland
| | | | - Daniela F Cusack
- Department of Ecosystem Science and Sustainability, Warner College of Natural Resources, Colorado State University, Fort Collins, CO, USA
| | - Steven J Hall
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA, USA
| | - Julie D Jastrow
- Environmental Science Division, Argonne National Laboratory, Lemont, IL, USA
| | - Andrea Jilling
- Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK, USA
| | - Kenneth M Kemner
- Biosciences Division, Argonne National Laboratory, Lemont, IL, USA
| | - Markus Kleber
- Department of Crop and Soil Science, Oregon State University, Corvallis, OR, USA
| | - Xiao-Jun Allen Liu
- Department of Microbiology, University of Massachusetts, Amherst, MA, USA
| | - Jennifer Pett-Ridge
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | | |
Collapse
|
13
|
Bel J, Legout A, Saint-André L, Hall SJ, Löfgren S, Laclau JP, van der Heijden G. Conventional analysis methods underestimate the plant-available pools of calcium, magnesium and potassium in forest soils. Sci Rep 2020; 10:15703. [PMID: 32973312 PMCID: PMC7519158 DOI: 10.1038/s41598-020-72741-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [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: 06/01/2020] [Accepted: 09/04/2020] [Indexed: 11/19/2022] Open
Abstract
The plant-available pools of calcium, magnesium and potassium are assumed to be stored in the soil as exchangeable cations adsorbed on the cation exchange complex. In numerous forest ecosystems, despite very low plant-available pools, elevated forest productivities are sustained. We hypothesize that trees access nutrient sources in the soil that are currently unaccounted by conventional soil analysis methods. We carried out an isotopic dilution assay to quantify the plant-available pools of calcium, magnesium and potassium and trace the soil phases that support these pools in 143 individual soil samples covering 3 climatic zones and 5 different soil types. For 81%, 87% and 90% of the soil samples (respectively for Ca, Mg and K), the plant-available pools measured by isotopic dilution were greater than the conventional exchangeable pool. This additional pool is most likely supported by secondary non-crystalline mineral phases in interaction with soil organic matter and represents in many cases (respectively 43%, 27% and 47% of the soil samples) a substantial amount of plant-available nutrient cations (50% greater than the conventional exchangeable pools) that is likely to play an essential role in the biogeochemical functioning of forest ecosystems, in particular when the resources of Ca, Mg and K are low.
Collapse
Affiliation(s)
- Jérémie Bel
- INRAE Grand-EST Nancy, UR 1138 Biogéochimie des Ecosystèmes Forestiers, Route d'Amance, 54280, Champenoux, France
| | - Arnaud Legout
- INRAE Grand-EST Nancy, UR 1138 Biogéochimie des Ecosystèmes Forestiers, Route d'Amance, 54280, Champenoux, France
| | - Laurent Saint-André
- INRAE Grand-EST Nancy, UR 1138 Biogéochimie des Ecosystèmes Forestiers, Route d'Amance, 54280, Champenoux, France
| | - Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, 251 Bessey Hall, Ames, IA, 50011, USA
| | - Stefan Löfgren
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, P.O. Box 7050, 750 07, Uppsala, Sweden
| | - Jean-Paul Laclau
- CIRAD, UMR 210 ecologie fonctionnelle et biogéochimie des sols et des agro-écosystèmes, Campus SupAgro, Bâtiment 12 - 2 place Viala, 34060, Montpellier Cedex 2, France
| | - Gregory van der Heijden
- INRAE Grand-EST Nancy, UR 1138 Biogéochimie des Ecosystèmes Forestiers, Route d'Amance, 54280, Champenoux, France.
| |
Collapse
|
14
|
Bai T, Wang P, Hall SJ, Wang F, Ye C, Li Z, Li S, Zhou L, Qiu Y, Guo J, Guo H, Wang Y, Hu S. Interactive global change factors mitigate soil aggregation and carbon change in a semi-arid grassland. Glob Chang Biol 2020; 26:5320-5332. [PMID: 32533721 DOI: 10.1111/gcb.15220] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 05/18/2020] [Indexed: 06/11/2023]
Abstract
The ongoing global change is multi-faceted, but the interactive effects of multiple drivers on the persistence of soil carbon (C) are poorly understood. We examined the effects of warming, reactive nitrogen (N) inputs (12 g N m-2 year-1 ) and altered precipitation (+ or - 30% ambient) on soil aggregates and mineral-associated C in a 4 year manipulation experiment with a semi-arid grassland on China's Loess Plateau. Our results showed that in the absence of N inputs, precipitation additions significantly enhanced soil aggregation and promoted the coupling between aggregation and both soil fungal biomass and exchangeable Mg2+ . However, N inputs negated the promotional effects of increased precipitation, mainly through suppressing fungal growth and altering soil pH and clay-Mg2+ -OC bridging. Warming increased C content in the mineral-associated fraction, likely by increasing inputs of root-derived C, and reducing turnover of existing mineral-associated C due to suppression of fungal growth and soil respiration. Together, our results provide new insights into the potential mechanisms through which multiple global change factors control soil C persistence in arid and semi-arid grasslands. These findings suggest that the interactive effects among global change factors should be incorporated to predict the soil C dynamics under future global change scenarios.
Collapse
Affiliation(s)
- Tongshuo Bai
- Ecosystem Ecology Laboratory, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Peng Wang
- Ecosystem Ecology Laboratory, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
| | - Fuwei Wang
- Ecosystem Ecology Laboratory, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Chenglong Ye
- Ecosystem Ecology Laboratory, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Zhen Li
- Ecosystem Ecology Laboratory, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Shijie Li
- Ecosystem Ecology Laboratory, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Luyao Zhou
- Ecosystem Ecology Laboratory, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yunpeng Qiu
- Ecosystem Ecology Laboratory, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Jiuxin Guo
- Ecosystem Ecology Laboratory, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
- International Magnesium Institute, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Hui Guo
- Ecosystem Ecology Laboratory, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yi Wang
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
| | - Shuijin Hu
- Ecosystem Ecology Laboratory, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
- Department of Entomology & Plant Pathology, North Carolina State University, Raleigh, NC, USA
| |
Collapse
|
15
|
Hall SJ, Huang W, Timokhin VI, Hammel KE. Lignin lags, leads, or limits the decomposition of litter and soil organic carbon. Ecology 2020; 101:e03113. [PMID: 32506475 DOI: 10.1002/ecy.3113] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [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: 01/28/2020] [Revised: 05/11/2020] [Accepted: 05/22/2020] [Indexed: 11/07/2022]
Abstract
Lignin's role in litter and soil organic carbon (SOC) decomposition remains contentious. Lignin decomposition was traditionally thought to increase during midstage litter decomposition, when cellulose occlusion by lignin began to limit mass loss. Alternatively, lignin decomposition could be greatest in fresh litter as a consequence of co-metabolism, and lignin might decompose faster than bulk SOC. To test these competing hypotheses, we incubated 10 forest soils with C4 grass litter (amended with 13 C-labeled or unlabeled lignin) over 2 yr and measured soil respiration and its isotope composition. Early lignin decomposition was greatest in 5 of 10 soils, consistent with the co-metabolism hypothesis. However, lignin decomposition peaked 6-24 months later in the other five soils, consistent with the substrate-limitation hypothesis; these soils were highly acidic. Rates of lignin, litter, and SOC decomposition tended to converge over time. Cumulative lignin decomposition was never greater than SOC decomposition; lignin decomposition was significantly lower than SOC decomposition in six soils. Net nitrogen mineralization predicted lignin decomposition ratios relative to litter and SOC. Although the onset of lignin decomposition can indeed be rapid, lignin still presents a likely bottleneck in litter and SOC decomposition, meriting a reconsideration of lignin's role in modern decomposition paradigms.
Collapse
Affiliation(s)
- Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, 50011, USA
| | - Wenjuan Huang
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, 50011, USA
| | - Vitaliy I Timokhin
- Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin, Madison, Wisconsin, 53706, USA
| | - Kenneth E Hammel
- U.S. Forest Products Laboratory, Madison, Wisconsin, 53726, USA.,Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, 53706, USA
| |
Collapse
|
16
|
Huang W, Ye C, Hockaday WC, Hall SJ. Trade-offs in soil carbon protection mechanisms under aerobic and anaerobic conditions. Glob Chang Biol 2020; 26:3726-3737. [PMID: 32227617 DOI: 10.1111/gcb.15100] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 03/05/2020] [Accepted: 03/23/2020] [Indexed: 06/10/2023]
Abstract
Oxygen (O2 ) limitation is generally understood to suppress oil carbon (C) decomposition and is a key mechanism impacting terrestrial C stocks under global change. Yet, O2 limitation may differentially impact kinetic or thermodynamic versus physicochemical C protection mechanisms, challenging our understanding of how soil C may respond to climate-mediated changes in O2 dynamics. Although O2 limitation may suppress decomposition of new litter C inputs, release of physicochemically protected C due to iron (Fe) reduction could potentially sustain soil C losses. To test this trade-off, we incubated two disparate upland soils that experience periodic O2 limitation-a tropical rainforest Oxisol and a temperate cropland Mollisol-with added litter under either aerobic (control) or anaerobic conditions for 1 year. Anoxia suppressed total C loss by 27% in the Oxisol and by 41% in the Mollisol relative to the control, mainly due to the decrease in litter-C decomposition. However, anoxia sustained or even increased decomposition of native soil-C (11.0% vs. 12.4% in the control for the Oxisol and 12.5% vs. 5.3% in the control for the Mollisol, in terms of initial soil C mass), and it stimulated losses of metal- or mineral-associated C. Solid-state 13 C nuclear magnetic resonance spectroscopy demonstrated that anaerobic conditions decreased protein-derived C but increased lignin- and carbohydrate-C relative to the control. Our results indicate a trade-off between physicochemical and kinetic/thermodynamic C protection mechanisms under anaerobic conditions, whereby decreased decomposition of litter C was compensated by more extensive loss of mineral-associated soil C in both soils. This challenges the common assumption that anoxia inherently protects soil C and illustrates the vulnerability of mineral-associated C under anaerobic events characteristic of a warmer and wetter future climate.
Collapse
Affiliation(s)
- Wenjuan Huang
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
| | - Chenglong Ye
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
- Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | | | - Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
| |
Collapse
|
17
|
Wilsey B, Xu X, Polley HW, Hofmockel K, Hall SJ. Lower soil carbon stocks in exotic vs. native grasslands are driven by carbonate losses. Ecology 2020; 101:e03039. [PMID: 32134498 DOI: 10.1002/ecy.3039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [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: 12/18/2019] [Accepted: 02/10/2020] [Indexed: 11/09/2022]
Abstract
Global change includes invasion by exotic (nonnative) plant species and altered precipitation patterns, and these factors may affect terrestrial carbon (C) storage. We measured soil C changes in experimental mixtures of all exotic or all native grassland plant species under two levels of summer drought stress (0 and +128 mm). After 8 yr, soils were sampled in 10-cm increments to 100-cm depth to determine if soil C differed among treatments in deeper soils. Total soil C (organic + inorganic) content was significantly higher under native than exotic plantings, and differences increased with depth. Surprisingly, differences after 8 yr in C were due to carbonate and not organic C fractions, where carbonate was ~250 g C/m2 lower to 1-m soil depth under exotic than native plantings. Our results indicate that soil carbonate is an active pool and can respond to differences in plant species traits over timescales of years. Significant losses of inorganic C might be avoided by conserving native grasslands in subhumid ecosystems.
Collapse
Affiliation(s)
- Brian Wilsey
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, 251 Bessey Hall, Ames, Iowa, 50011, USA
| | - Xia Xu
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, 251 Bessey Hall, Ames, Iowa, 50011, USA
| | - H Wayne Polley
- USDA-ARS, Grassland, Soil and Water Research Laboratory, 808 East Blackland Road, Temple, Texas, 76502, USA
| | - Kirsten Hofmockel
- Pacific Northwest National Laboratory, 902 Battelle Blvd., Richland, WA, USA
| | - Steven J Hall
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, 251 Bessey Hall, Ames, Iowa, 50011, USA
| |
Collapse
|
18
|
Lambrecht N, Katsev S, Wittkop C, Hall SJ, Sheik CS, Picard A, Fakhraee M, Swanner ED. Biogeochemical and physical controls on methane fluxes from two ferruginous meromictic lakes. Geobiology 2020; 18:54-69. [PMID: 31592570 DOI: 10.1111/gbi.12365] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 08/20/2019] [Accepted: 08/31/2019] [Indexed: 05/28/2023]
Abstract
Meromictic lakes with anoxic bottom waters often have active methane cycles whereby methane is generally produced biogenically under anoxic conditions and oxidized in oxic surface waters prior to reaching the atmosphere. Lakes that contain dissolved ferrous iron in their deep waters (i.e., ferruginous) are rare, but valuable, as geochemical analogues of the conditions that dominated the Earth's oceans during the Precambrian when interactions between the iron and methane cycles could have shaped the greenhouse regulation of the planet's climate. Here, we explored controls on the methane fluxes from Brownie Lake and Canyon Lake, two ferruginous meromictic lakes that contain similar concentrations (max. >1 mM) of dissolved methane in their bottom waters. The order Methanobacteriales was the dominant methanogen detected in both lakes. At Brownie Lake, methanogen abundance, an increase in methane concentration with respect to depths closer to the sediment, and isotopic data suggest methanogenesis is an active process in the anoxic water column. At Canyon Lake, methanogenesis occurred primarily in the sediment. The most abundant aerobic methane-oxidizing bacteria present in both water columns were associated with the Gammaproteobacteria, with little evidence of anaerobic methane oxidizing organisms being present or active. Direct measurements at the surface revealed a methane flux from Brownie Lake that was two orders of magnitude greater than the flux from Canyon Lake. Comparison of measured versus calculated turbulent diffusive fluxes indicates that most of the methane flux at Brownie Lake was non-diffusive. Although the turbulent diffusive methane flux at Canyon Lake was attenuated by methane oxidizing bacteria, dissolved methane was detected in the epilimnion, suggestive of lateral transport of methane from littoral sediments. These results highlight the importance of direct measurements in estimating the total methane flux from water columns, and that non-diffusive transport of methane may be important to consider from other ferruginous systems.
Collapse
Affiliation(s)
- Nicholas Lambrecht
- Department of Geological and Atmospheric Sciences, Iowa State University, Ames, IA, USA
| | - Sergei Katsev
- Department of Physics, University of Minnesota Duluth, Duluth, MN, USA
- Large Lakes Observatory, University of Minnesota Duluth, Duluth, MN, USA
| | - Chad Wittkop
- Department of Chemistry and Geology, Minnesota State University, Mankato, MN, USA
| | - Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
| | - Cody S Sheik
- Large Lakes Observatory, University of Minnesota Duluth, Duluth, MN, USA
- Department of Biology, University of Minnesota Duluth, Duluth, MN, USA
| | - Aude Picard
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV, USA
| | - Mojtaba Fakhraee
- Large Lakes Observatory, University of Minnesota Duluth, Duluth, MN, USA
| | - Elizabeth D Swanner
- Department of Geological and Atmospheric Sciences, Iowa State University, Ames, IA, USA
| |
Collapse
|
19
|
Huang W, Hammel KE, Hao J, Thompson A, Timokhin VI, Hall SJ. Enrichment of Lignin-Derived Carbon in Mineral-Associated Soil Organic Matter. Environ Sci Technol 2019; 53:7522-7531. [PMID: 31177774 DOI: 10.1021/acs.est.9b01834] [Citation(s) in RCA: 28] [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] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
A modern paradigm of soil organic matter proposes that persistent carbon (C) derives primarily from microbial residues interacting with minerals, challenging older ideas that lignin moieties contribute to soil C because of inherent recalcitrance. We proposed that aspects of these old and new paradigms can be partially reconciled by considering interactions between lignin decomposition products and redox-sensitive iron (Fe) minerals. An Fe-rich tropical soil (with C4 litter and either 13C-labeled or unlabeled lignin) was pretreated with different durations of anaerobiosis (0-12 days) and incubated aerobically for 317 days. Only 5.7 ± 0.2% of lignin 13C was mineralized to CO2 versus 51.2 ± 0.4% of litter C. More added lignin-derived C (48.2 ± 0.9%) than bulk litter-derived C (30.6 ± 0.7%) was retained in mineral-associated organic matter (MAOM; density >1.8 g cm-3), and 12.2 ± 0.3% of lignin-derived C vs 6.4 ± 0.1% of litter C accrued in clay-sized (<2 μm) MAOM. Longer anaerobic pretreatments increased added lignin-derived C associated with Fe, according to extractions and nanoscale secondary ion mass spectrometry (NanoSIMS). Microbial residues are important, but lignin-derived C may also contribute disproportionately to MAOM relative to bulk litter-derived C, especially following redox-sensitive biogeochemical interactions.
Collapse
Affiliation(s)
- Wenjuan Huang
- Department of Ecology, Evolution, and Organismal Biology , Iowa State University , Ames , Iowa 50011 , United States
- Key laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden , Chinese Academy of Sciences , Guangzhou 510650 , China
| | - Kenneth E Hammel
- US Forest Products Laboratory , Madison , Wisconsin 53726 , United States
- Department of Bacteriology , University of Wisconsin , Madison , Wisconsin 53706 , United States
| | - Jialong Hao
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics , Chinese Academy of Sciences , Beijing 100029 , China
| | - Aaron Thompson
- Department of Crop and Soil Sciences , The University of Georgia , Athens , Georgia 30602 , United States
| | - Vitaliy I Timokhin
- University of Wisconsin , Wisconsin Energy Institute, DOE Great Lakes Bioenergy Research Center , Madison , Wisconsin 53706 , United States
| | - Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology , Iowa State University , Ames , Iowa 50011 , United States
| |
Collapse
|
20
|
Ye C, Chen D, Hall SJ, Pan S, Yan X, Bai T, Guo H, Zhang Y, Bai Y, Hu S. Reconciling multiple impacts of nitrogen enrichment on soil carbon: plant, microbial and geochemical controls. Ecol Lett 2018; 21:1162-1173. [PMID: 29781214 DOI: 10.1111/ele.13083] [Citation(s) in RCA: 50] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 04/12/2018] [Indexed: 01/26/2023]
Abstract
Impacts of reactive nitrogen (N) inputs on ecosystem carbon (C) dynamics are highly variable, and the underlying mechanisms remain unclear. Here, we proposed a new conceptual framework that integrates plant, microbial and geochemical mechanisms to reconcile diverse and contrasting impacts of N on soil C. This framework was tested using long-term N enrichment and acid addition experiments in a Mongolian steppe grassland. Distinct mechanisms could explain effects of N on particulate and mineral-associated soil C pools, potentially explaining discrepancies among previous N addition studies. While plant production predominated particulate C changes, N-induced soil acidification strongly affected mineral-associated C through decreased microbial growth and pH-sensitive associations between iron and aluminium minerals and C. Our findings suggest that effects of N-induced acidification on microbial respiration and geochemical properties should be included in Earth system models that predict ecosystem C budgets under future N deposition/input scenarios.
Collapse
Affiliation(s)
- Chenglong Ye
- Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.,Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, 50011, USA
| | - Dima Chen
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, 50011, USA
| | - Shang Pan
- Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xuebin Yan
- Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Tongshuo Bai
- Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Hui Guo
- Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yi Zhang
- Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yongfei Bai
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Shuijin Hu
- Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.,Department of Entomology & Plant Pathology, North Carolina State University, Raleigh, NC, 27695, USA
| |
Collapse
|
21
|
Bianchi E, Stermer A, Boekelheide K, Sigman M, Hall SJ, Reyes G, Dere E, Hwang K. High-quality human and rat spermatozoal RNA isolation for functional genomic studies. Andrology 2018; 6:374-383. [PMID: 29470852 DOI: 10.1111/andr.12471] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/11/2017] [Accepted: 01/04/2018] [Indexed: 12/30/2022]
Abstract
Sperm RNA is a sensitive monitoring endpoint for male reproductive toxicants, and a potential biomarker to assess male infertility and sperm quality. However, isolation of sperm RNA is a challenging procedure due to the heterogeneous population of cells present in the ejaculate, the low yield of RNA per spermatozoon, and the absence of 18S and 28S ribosomal RNA subunits. The unique biology of spermatozoa has created some uncertainty in the field about RNA isolation methods, indicating the need for rigorous quality control checks to ensure reproducibility of data generated from sperm RNA. Therefore, we developed a reliable and effective protocol for RNA isolation from rat and human spermatozoa that delivers highly purified and intact RNA, verified using RNA-specific electrophoretic chips and molecular biology approaches such as RT-PCR and Western blot analysis. The sperm RNA isolation technique was optimized using rat spermatozoa and then adapted to human spermatozoa. Three steps in the sperm isolation procedure, epididymal fluid collection, sperm purification, and spermatozoon RNA extraction, were evaluated and assessed. The sperm RNA extraction methodology consists of collection of rat epididymal fluid with repeated needle punctures of the epididymis, somatic cell elimination using detergent-based somatic cell lysis buffer (SCLB) and the use of RNA isolation Kit. Rat sperm heads are more resistant to disruption than human spermatozoa, necessitating the addition of mechanical lysis with microbeads and heat in the rat protocol, whereas the human sperm protocol only required lysis buffer. In conclusion, this methodology results in reliable and consistent isolation of high-quality sperm RNA. Using this technique will aid in translation of data collected from animal models, and reproducibility of clinical assessment of male factor fertility using RNA molecular biomarkers.
Collapse
Affiliation(s)
- E Bianchi
- Division of Urology, Rhode Island Hospital, Providence, RI, USA.,Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - A Stermer
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - K Boekelheide
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - M Sigman
- Division of Urology, Rhode Island Hospital, Providence, RI, USA.,Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - S J Hall
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - G Reyes
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - E Dere
- Division of Urology, Rhode Island Hospital, Providence, RI, USA.,Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - K Hwang
- Division of Urology, Rhode Island Hospital, Providence, RI, USA.,Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| |
Collapse
|
22
|
Hall SJ, Huang W, Hammel KE. An optical method for carbon dioxide isotopes and mole fractions in small gas samples: Tracing microbial respiration from soil, litter, and lignin. Rapid Commun Mass Spectrom 2017; 31:1938-1946. [PMID: 28851092 DOI: 10.1002/rcm.7973] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 08/21/2017] [Accepted: 08/23/2017] [Indexed: 06/07/2023]
Abstract
RATIONALE Carbon dioxide isotope (δ13 C value) measurements enable quantification of the sources of soil microbial respiration, thus informing ecosystem C dynamics. Tunable diode lasers (TDLs) can precisely measure CO2 isotopes at low cost and high throughput, but are seldom used for small samples (≤5 mL). We developed a TDL method for CO2 mole fraction ([CO2 ]) and δ13 C analysis of soil microcosms. METHODS Peaks in infrared absorbance following constant volume sample injection to a carrier were used to independently measure [12 CO2 ] and [13 CO2 ] for subsequent calculation of δ13 C values. Using parallel soil incubations receiving differing C substrates, we partitioned respiration from three sources using mixing models: native soil organic matter (SOM), added litter, and synthetic lignin containing a 13 C label at Cβ of the propyl side chain. RESULTS Once-daily TDL calibration enabled accurate quantification of δ13 C values and [CO2 ] compared with isotope ratio mass spectrometry (IRMS), with long-term external precision of 0.17 and 0.31‰ for 5 and 1 mL samples, respectively, and linear response between 400 and 5000 μmol mol-1 CO2 . Production of CO2 from native soil C, added litter, and lignin Cβ varied over four orders of magnitude. Multiple-pool first-order decay models fitted to data (R2 > 0.98) indicated substantially slower turnover for lignin Cβ (17 years) than for the dominant pool of litter (1.3 years) and primed soil C (3.9 years). CONCLUSIONS Our TDL method provides a flexible, precise, and high-throughput (60 samples h-1 ) alternative to IRMS for small samples. This enables the use of C isotopes in increasingly sophisticated experiments to test biogeochemical controversies, such as the fate of lignins in soil.
Collapse
Affiliation(s)
- Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, 251 Bessey Hall, Ames, IA, 50011, USA
| | - Wenjuan Huang
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, 251 Bessey Hall, Ames, IA, 50011, USA
| | - Kenneth E Hammel
- US Forest Products Laboratory, Madison, WI, 53726, USA
- Department of Bacteriology, University of Wisconsin, Madison, WI, 53706, USA
| |
Collapse
|
23
|
Russell AE, Hall SJ, Raich JW. Tropical tree species traits drive soil cation dynamics via effects on pH: a proposed conceptual framework. ECOL MONOGR 2017. [DOI: 10.1002/ecm.1274] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Ann E. Russell
- Department of Natural Resource Ecology and Management Iowa State University Ames Iowa 50011 USA
| | - Steven J. Hall
- Department of Ecology, Evolution and Organismal Biology Iowa State University Ames Iowa 50011 USA
| | - James W. Raich
- Department of Ecology, Evolution and Organismal Biology Iowa State University Ames Iowa 50011 USA
| |
Collapse
|
24
|
Gabor RS, Hall SJ, Eiriksson DP, Jameel Y, Millington M, Stout T, Barnes ML, Gelderloos A, Tennant H, Bowen GJ, Neilson BT, Brooks PD. Persistent Urban Influence on Surface Water Quality via Impacted Groundwater. Environ Sci Technol 2017; 51:9477-9487. [PMID: 28730814 DOI: 10.1021/acs.est.7b00271] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Growing urban environments stress hydrologic systems and impact downstream water quality. We examined a third-order catchment that transitions from an undisturbed mountain environment into urban Salt Lake City, Utah. We performed synoptic surveys during a range of seasonal baseflow conditions and utilized multiple lines of evidence to identify mechanisms by which urbanization impacts water quality. Surface water chemistry did not change appreciably until several kilometers into the urban environment, where concentrations of solutes such as chloride and nitrate increase quickly in a gaining reach. Groundwater springs discharging in this gaining system demonstrate the role of contaminated baseflow from an aquifer in driving stream chemistry. Hydrometric and hydrochemical observations were used to estimate that the aquifer contains approximately 18% water sourced from the urban area. The carbon and nitrogen dynamics indicated the urban aquifer also serves as a biogeochemical reactor. The evidence of surface water-groundwater exchange on a spatial scale of kilometers and time scale of months to years suggests a need to evolve the hydrologic model of anthropogenic impacts to urban water quality to include exchange with the subsurface. This has implications on the space and time scales of water quality mitigation efforts.
Collapse
Affiliation(s)
- Rachel S Gabor
- Global Change and Sustainability Center, University of Utah , 115 South 1460 East, Salt Lake City, Utah 84112, United States
- Department of Geology and Geophysics, University of Utah , 115 South 1460 East, Salt Lake City, Utah 84112, United States
| | - Steven J Hall
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University , 251 Bessey Hall, Ames, Iowa 50011, United States
| | - David P Eiriksson
- Global Change and Sustainability Center, University of Utah , 115 South 1460 East, Salt Lake City, Utah 84112, United States
| | - Yusuf Jameel
- Department of Geology and Geophysics, University of Utah , 115 South 1460 East, Salt Lake City, Utah 84112, United States
| | - Mallory Millington
- Department of Geology and Geophysics, University of Utah , 115 South 1460 East, Salt Lake City, Utah 84112, United States
| | - Trinity Stout
- Civil and Environmental Engineering, Utah Water Research Laboratory, Utah State University , 8200 Old Main Hill, Logan, Utah 84322-8200, United States
| | - Michelle L Barnes
- Civil and Environmental Engineering, Utah Water Research Laboratory, Utah State University , 8200 Old Main Hill, Logan, Utah 84322-8200, United States
| | - Andrew Gelderloos
- Department of Geology and Geophysics, University of Utah , 115 South 1460 East, Salt Lake City, Utah 84112, United States
| | - Hyrum Tennant
- Civil and Environmental Engineering, Utah Water Research Laboratory, Utah State University , 8200 Old Main Hill, Logan, Utah 84322-8200, United States
| | - Gabriel J Bowen
- Global Change and Sustainability Center, University of Utah , 115 South 1460 East, Salt Lake City, Utah 84112, United States
- Department of Geology and Geophysics, University of Utah , 115 South 1460 East, Salt Lake City, Utah 84112, United States
| | - Bethany T Neilson
- Civil and Environmental Engineering, Utah Water Research Laboratory, Utah State University , 8200 Old Main Hill, Logan, Utah 84322-8200, United States
| | - Paul D Brooks
- Global Change and Sustainability Center, University of Utah , 115 South 1460 East, Salt Lake City, Utah 84112, United States
- Department of Geology and Geophysics, University of Utah , 115 South 1460 East, Salt Lake City, Utah 84112, United States
| |
Collapse
|
25
|
Ayansina D, Black C, Hall SJ, Marks A, Millar C, Prescott GJ, Wilde K, Bhattacharya S. Long term effects of gestational hypertension and pre-eclampsia on kidney function: Record linkage study. Pregnancy Hypertens 2016; 6:344-349. [PMID: 27939480 PMCID: PMC5161246 DOI: 10.1016/j.preghy.2016.08.231] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 08/05/2016] [Indexed: 11/29/2022]
Abstract
We examine risk of chronic kidney disease (CKD) after pregnancy hypertension. We found increased risk of chronic kidney disease after gestational hypertension. Risk of chronic kidney disease was further increased after preeclampsia. Women with pregnancy hypertension develop CKD earlier than normotensive women.
Objective To assess the long term effects of hypertensive disorders of pregnancy on renal function. Design Cohort study where exposure was gestational hypertension or preeclampsia in the first pregnancy. Normotensive women formed the comparison group. Setting Aberdeen, Scotland. Participants All women with date of birth on or before 30th June 1969 and at least their first singleton delivery recorded in the Aberdeen Maternity and Neonatal Databank. Methods Participants were linked to the Renal Biochemistry Register, Scottish Morbidity Records, Scottish Renal Registry and National Register for deaths. Main outcome measures Occurrence of chronic kidney disease (CKD) as identified from renal function tests in later life, hospital admissions or death from kidney disease or recorded as receiving renal replacement therapy. Results CKD was diagnosed in 7.5% and 5.2% of women who previously had GH and PE respectively compared to 3.9% in normotensive women. The unadjusted odds ratio (95% confidence interval) of having CKD in PE was 2.04 (1.53, 2.71) and that for GH was 1.37 (1.15, 1.65), while the adjusted odds ratio (95% confidence interval) of CKD was 1.93 (1.44, 2.57) and 1.36 (1.13, 1.63) in women with PE and GH respectively. Kaplan–Meier curves of survival time to development of chronic kidney disease revealed that women with preeclampsia were susceptible to kidney function impairment earliest, followed by those with gestational hypertension. Conclusions There was an increased subsequent risk of CKD associated with hypertensive disorders of pregnancy. Women with GH and PE were also found to have CKD earlier than normotensive women.
Collapse
Affiliation(s)
- D Ayansina
- Division of Applied Health Sciences, University of Aberdeen, United Kingdom.
| | - C Black
- Chronic Diseases Group, Division of Applied Health Sciences, University of Aberdeen, United Kingdom.
| | - S J Hall
- Chronic Diseases Group, Division of Applied Health Sciences, University of Aberdeen, United Kingdom
| | - A Marks
- Chronic Diseases Group, Division of Applied Health Sciences, University of Aberdeen, United Kingdom
| | | | - G J Prescott
- Division of Applied Health Sciences, University of Aberdeen, United Kingdom
| | - K Wilde
- Division of Applied Health Sciences, University of Aberdeen, United Kingdom.
| | - S Bhattacharya
- Obstetric Epidemiology, Division of Applied Health Sciences, University of Aberdeen, United Kingdom.
| |
Collapse
|
26
|
Hall SJ, Baker MA, Jones SB, Stark JM, Bowling DR. Contrasting soil nitrogen dynamics across a montane meadow and urban lawn in a semi-arid watershed. Urban Ecosyst 2016. [DOI: 10.1007/s11252-016-0538-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
27
|
Hall SJ, Weintraub SR, Eiriksson D, Brooks PD, Baker MA, Bowen GJ, Bowling DR. Stream Nitrogen Inputs Reflect Groundwater Across a Snowmelt-Dominated Montane to Urban Watershed. Environ Sci Technol 2016; 50:1137-1146. [PMID: 26744921 DOI: 10.1021/acs.est.5b04805] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Snowmelt dominates the hydrograph of many temperate montane streams, yet little work has characterized how streamwater sources and nitrogen (N) dynamics vary across wildland to urban land use gradients in these watersheds. Across a third-order catchment in Salt Lake City, Utah, we asked where and when groundwater vs shallow surface water inputs controlled stream discharge and N dynamics. Stream water isotopes (δ(2)H and δ(18)O) reflected a consistent snowmelt water source during baseflow. Near-chemostatic relationships between conservative ions and discharge implied that groundwater dominated discharge year-round across the montane and urban sites, challenging the conceptual emphasis on direct stormwater inputs to urban streams. Stream and groundwater NO3(-) concentrations remained consistently low during snowmelt and baseflow in most montane and urban stream reaches, indicating effective subsurface N retention or denitrification and minimal impact of fertilizer or deposition N sources. Rather, NO3(-) concentrations increased 50-fold following urban groundwater inputs, showing that subsurface flow paths potentially impact nutrient loading more than surficial land use. Isotopic composition of H2O and NO3(-) suggested that snowmelt-derived urban groundwater intercepted NO3(-) from leaking sewers. Sewer maintenance could potentially mitigate hotspots of stream N inputs at mountain/valley transitions, which have been largely overlooked in semiarid urban ecosystems.
Collapse
Affiliation(s)
| | - Samantha R Weintraub
- Department of Geology and Geophysics, University of Utah , 115 South 1460 East, Salt Lake City, Utah 84112, United States
| | | | - Paul D Brooks
- Department of Geology and Geophysics, University of Utah , 115 South 1460 East, Salt Lake City, Utah 84112, United States
| | - Michelle A Baker
- Department of Biology and the Ecology Center, Utah State University , 5305 Old Main Hill, Logan, Utah 84322, United States
| | - Gabriel J Bowen
- Department of Geology and Geophysics, University of Utah , 115 South 1460 East, Salt Lake City, Utah 84112, United States
| | | |
Collapse
|
28
|
Hall SJ, Peacock JDH, Cochrane LA, Peacock O, Tierney GM, Tou SIH, Lund JN. The bowel cancer awareness campaign 'Be Clear on Cancer': sustained increased pressure on resources and over-accessed by higher social grades with no increase in cancer detected. Colorectal Dis 2016; 18:195-9. [PMID: 26333198 DOI: 10.1111/codi.13107] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [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: 03/10/2015] [Accepted: 05/31/2015] [Indexed: 02/08/2023]
Abstract
AIM To evaluate the impact of the national 'Be Clear on Cancer' bowel cancer reminder campaign on service and diagnosis at a single UK institution. Secondly, to evaluate the socio-economic background of patients referred before and after the reminder campaign compared with the regional demographic. METHOD Suspected cancer 2-week wait patients in the 3 months precampaign, postcampaign and after the reminder campaign were included. Demographics, investigations and diagnosis were recorded. The postcode was used to allocate a National Readership Survey social grade. RESULTS Three hundred and eighty-three referrals were received in the 3 months precampaign, 550 postcampaign and 470 postreminder campaign. There were significant increases in the monthly referral rates following the campaign (P < 0.001 in both the post- and postreminder periods). Significantly more patients from social grades AB and C1C2 than expected from regional demographics were referred precampaign and after the reminder campaign (P < 0.001 in each case). There were no significant differences between the proportions of patients diagnosed with colorectal cancer in the three study periods (P = 0.710). CONCLUSION The 'Be Clear on Cancer' bowel cancer campaign has had a significant sustained impact on resources. It has failed to increase referrals among lower socio-economic grades, leading to an increase in 'worried well' referrals and no change in numbers, or the stage, of colorectal cancers diagnosed.
Collapse
Affiliation(s)
- S J Hall
- Division of Urology, Royal Derby Hospital, Derby, UK
| | - J D H Peacock
- Division of Colorectal Surgery, Royal Derby Hospital, Derby, UK
| | | | - O Peacock
- Division of Surgery, School of Graduate Entry Medicine and Health, Royal Derby Hospital, University of Nottingham, Derby, UK
| | - G M Tierney
- Division of Colorectal Surgery, Royal Derby Hospital, Derby, UK
| | - S I H Tou
- Division of Colorectal Surgery, Royal Derby Hospital, Derby, UK
| | - J N Lund
- Division of Surgery, School of Graduate Entry Medicine and Health, Royal Derby Hospital, University of Nottingham, Derby, UK
| |
Collapse
|
29
|
Hall SJ, Hale RL, Baker MA, Bowling DR, Ehleringer JR. Riparian plant isotopes reflect anthropogenic nitrogen perturbations: robust patterns across land use gradients. Ecosphere 2015. [DOI: 10.1890/es15-00319.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
30
|
Hall SJ, Silver WL, Timokhin VI, Hammel KE. Lignin decomposition is sustained under fluctuating redox conditions in humid tropical forest soils. Glob Chang Biol 2015; 21:2818-2828. [PMID: 25711691 DOI: 10.1111/gcb.12908] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Accepted: 02/04/2015] [Indexed: 06/04/2023]
Abstract
Lignin mineralization represents a critical flux in the terrestrial carbon (C) cycle, yet little is known about mechanisms and environmental factors controlling lignin breakdown in mineral soils. Hypoxia is thought to suppress lignin decomposition, yet potential effects of oxygen (O2 ) variability in surface soils have not been explored. Here, we tested the impact of redox fluctuations on lignin breakdown in humid tropical forest soils during ten-week laboratory incubations. We used synthetic lignins labeled with 13 C in either of two positions (aromatic methoxyl or propyl side chain Cβ ) to provide highly sensitive and specific measures of lignin mineralization seldom employed in soils. Four-day redox fluctuations increased the percent contribution of methoxyl C to soil respiration relative to static aerobic conditions, and cumulative methoxyl-C mineralization was statistically equivalent under static aerobic and fluctuating redox conditions despite lower soil respiration in the latter treatment. Contributions of the less labile lignin Cβ to soil respiration were equivalent in the static aerobic and fluctuating redox treatments during periods of O2 exposure, and tended to decline during periods of O2 limitation, resulting in lower cumulative Cβ mineralization in the fluctuating treatment relative to the static aerobic treatment. However, cumulative mineralization of both the Cβ - and methoxyl-labeled lignins nearly doubled in the fluctuating treatment relative to the static aerobic treatment when total lignin mineralization was normalized to total O2 exposure. Oxygen fluctuations are thought to be suboptimal for canonical lignin-degrading microorganisms. However, O2 fluctuations drove substantial Fe reduction and oxidation, and reactive oxygen species generated during abiotic Fe oxidation might explain the elevated contribution of lignin to C mineralization. Iron redox cycling provides a potential mechanism for lignin depletion in soil organic matter. Couplings between soil moisture, redox fluctuations, and lignin breakdown provide a potential link between climate variability and the biochemical composition of soil organic matter.
Collapse
Affiliation(s)
- Steven J Hall
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA, 94720, USA
| | - Whendee L Silver
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA, 94720, USA
| | - Vitaliy I Timokhin
- Department of Biochemistry, Wisconsin Energy Institute, University of Wisconsin, Madison, WI, 53706, USA
| | - Kenneth E Hammel
- US Forest Products Laboratory, Madison, WI, 53726, USA
- Department of Bacteriology, University of Wisconsin, Madison, WI, 53706, USA
| |
Collapse
|
31
|
Hall SJ, Treffkorn J, Silver WL. Breaking the enzymatic latch: impacts of reducing conditions on hydrolytic enzyme activity in tropical forest soils. Ecology 2014. [DOI: 10.1890/13-2151.1] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
32
|
Beveridge MCM, Thilsted SH, Phillips MJ, Metian M, Troell M, Hall SJ. Meeting the food and nutrition needs of the poor: the role of fish and the opportunities and challenges emerging from the rise of aquaculture. J Fish Biol 2013; 83:1067-84. [PMID: 24090563 PMCID: PMC4283757 DOI: 10.1111/jfb.12187] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
People who are food and nutrition insecure largely reside in Asia and Sub-Saharan Africa and for many, fish represents a rich source of protein, micronutrients and essential fatty acids. The contribution of fish to household food and nutrition security depends upon availability, access and cultural and personal preferences. Access is largely determined by location, seasonality and price but at the individual level it also depends upon a person's physiological and health status and how fish is prepared, cooked and shared among household members. The sustained and rapid expansion of aquaculture over the past 30 years has resulted in >40% of all fish now consumed being derived from farming. While aquaculture produce increasingly features in the diets of many Asians, it is much less apparent among those living in Sub-Saharan Africa. Here, per capita fish consumption has grown little and despite the apparently strong markets and adequate biophysical conditions, aquaculture has yet to develop. The contribution of aquaculture to food and nutrition security is not only just an issue of where aquaculture occurs but also of what is being produced and how and whether the produce is as accessible as that from capture fisheries. The range of fish species produced by an increasingly globalized aquaculture industry differs from that derived from capture fisheries. Farmed fishes are also different in terms of their nutrient content, a result of the species being grown and of rearing methods. Farmed fish price affects access by poor consumers while the size at which fish is harvested influences both access and use. This paper explores these issues with particular reference to Asia and Africa and the technical and policy innovations needed to ensure that fish farming is able to fulfil its potential to meet the global population's food and nutrition needs.
Collapse
Affiliation(s)
- M C M Beveridge
- WorldFishP. O. Box 51289, Ridgeway, Lusaka, Zambia
- † Author to whom correspondence should be addressed. Tel.: +260 211 257939/40;
| | - S H Thilsted
- WorldFishHouse 22B, Road 7, Block F, Banani, Dhaka 1213, Bangladesh
| | - M J Phillips
- WorldFish, Jalan Batu MaungBatu Maung, 11960 Bayan Lepas, Penang, Malaysia
| | - M Metian
- Stockholm Resilience Center, Stockholm UniversitySE-106 91 Stockholm, Sweden
| | - M Troell
- Stockholm Resilience Center, Stockholm UniversitySE-106 91 Stockholm, Sweden
- Beijer Institute of Ecological EconomicsStockholm, Sweden
| | - S J Hall
- WorldFishHouse 22B, Road 7, Block F, Banani, Dhaka 1213, Bangladesh
| |
Collapse
|
33
|
Hall SJ, Silver WL. Iron oxidation stimulates organic matter decomposition in humid tropical forest soils. Glob Chang Biol 2013; 19:2804-13. [PMID: 23606589 DOI: 10.1111/gcb.12229] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 03/18/2013] [Indexed: 05/14/2023]
Abstract
Humid tropical forests have the fastest rates of organic matter decomposition globally, which often coincide with fluctuating oxygen (O2 ) availability in surface soils. Microbial iron (Fe) reduction generates reduced iron [Fe(II)] under anaerobic conditions, which oxidizes to Fe(III) under subsequent aerobic conditions. We demonstrate that Fe (II) oxidation stimulates organic matter decomposition via two mechanisms: (i) organic matter oxidation, likely driven by reactive oxygen species; and (ii) increased dissolved organic carbon (DOC) availability, likely driven by acidification. Phenol oxidative activity increased linearly with Fe(II) concentrations (P < 0.0001, pseudo R(2) = 0.79) in soils sampled within and among five tropical forest sites. A similar pattern occurred in the absence of soil, suggesting an abiotic driver of this reaction. No phenol oxidative activity occurred in soils under anaerobic conditions, implying the importance of oxidants such as O2 or hydrogen peroxide (H2 O2 ) in addition to Fe(II). Reactions between Fe(II) and H2 O2 generate hydroxyl radical, a strong nonselective oxidant of organic compounds. We found increasing consumption of H2 O2 as soil Fe(II) concentrations increased, suggesting that reactive oxygen species produced by Fe(II) oxidation explained variation in phenol oxidative activity among samples. Amending soils with Fe(II) at field concentrations stimulated short-term C mineralization by up to 270%, likely via a second mechanism. Oxidation of Fe(II) drove a decrease in pH and a monotonic increase in DOC; a decline of two pH units doubled DOC, likely stimulating microbial respiration. We obtained similar results by manipulating soil acidity independently of Fe(II), implying that Fe(II) oxidation affected C substrate availability via pH fluctuations, in addition to producing reactive oxygen species. Iron oxidation coupled to organic matter decomposition contributes to rapid rates of C cycling across humid tropical forests in spite of periodic O2 limitation, and may help explain the rapid turnover of complex C molecules in these soils.
Collapse
Affiliation(s)
- Steven J Hall
- Department of Environmental Science, Policy, and Management, University of California-Berkeley, Berkeley, CA 94720, USA.
| | | |
Collapse
|
34
|
Gray NM, Hall SJ, Browne S, Macleod U, Mitchell E, Lee AJ, Johnston M, Wyke S, Samuel L, Weller D, Campbell NC. Modifiable and fixed factors predicting quality of life in people with colorectal cancer. Br J Cancer 2011; 104:1697-703. [PMID: 21559017 PMCID: PMC3111166 DOI: 10.1038/bjc.2011.155] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [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] [Indexed: 12/23/2022] Open
Abstract
Background: People with colorectal cancer have impaired quality of life (QoL). We investigated what factors were most highly associated with it. Methods: Four hundred and ninety-six people with colorectal cancer completed questionnaires about QoL, functioning, symptoms, co-morbidity, cognitions and personal and social factors. Disease, treatment and co-morbidity data were abstracted from case notes. Multiple linear regression identified modifiable and unmodifiable factors independently predictive of global quality of life (EORTC-QLQ-C30). Results: Of unmodifiable factors, female sex (P<0.001), more self-reported co-morbidities (P=0.006) and metastases at diagnosis (P=0.036) significantly predicted poorer QoL, but explained little of the variability in the model (R2=0.064). Adding modifiable factors, poorer role (P<0.001) and social functioning (P=0.003), fatigue (P=0.001), dyspnoea (P=0.001), anorexia (P<0.001), depression (P<0.001) and worse perceived consequences (P=0.013) improved the model fit considerably (R2=0.574). Omitting functioning subscales resulted in recent diagnosis (P=0.002), lower perceived personal control (P=0.020) and travel difficulties (P<0.001) becoming significant predictors. Conclusion: Most factors affecting QoL are modifiable, especially symptoms (fatigue, anorexia, dyspnoea) and depression. Beliefs about illness are also important. Unmodifiable factors, including metastatic (or unstaged) disease at diagnosis, have less impact. There appears to be potential for interventions to improve QoL in patients with colorectal cancer.
Collapse
Affiliation(s)
- N M Gray
- Centre of Academic Primary Care, University of Aberdeen, Foresterhill Health Centre, Westburn Road, Aberdeen AB25 2AY, UK.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
|
36
|
Hall SJ, Brown SE, Porter GJR, Steel J, Paisley K, Watkins RM, Holgate C. Negative axillary ultrasound in primary breast cancer: how reassured should we really be? Breast Cancer Res 2009. [PMCID: PMC4284851 DOI: 10.1186/bcr2390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
37
|
Hall SJ, Brown SE, Porter GJR, Steel J, Paisley K, Watkins RM, Holgate C. Axillary ultrasound in staging breast cancer: diagnostic accuracy and effect on subsequent axillary surgery - the Plymouth experience. Breast Cancer Res 2009. [PMCID: PMC4284852 DOI: 10.1186/bcr2391] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
38
|
Abstract
We describe the development of a sweat test centered protocol for disclosure and diagnosis of Cystic Fibrosis. Our protocol aims to identify infants early, minimizes the time of uncertainty for the parents, and yet gives them time to begin to come to terms with the possibility of diagnosis. Over a 9-year period 295,247 newborn infants were screened for CF in Wales, of whom 121 infants were diagnosed as having CF. During this period there were four false negatives (3.3%). Parental satisfaction with the process appears very high 6 months after disclosure.
Collapse
Affiliation(s)
- I J M Doull
- Respiratory/Cystic Fibrosis Unit, Children's Hospital for Wales, Cardiff, Wales, United Kingdom.
| | | | | |
Collapse
|
39
|
Abstract
Objective: The purpose of this study was to determine the susceptibility of organisms causing otitis externa (OE) to the essential oil of Melaleuca alternifolia, or tea tree oil (TTO).Methods: Fifty-seven swabs were taken from the ears of 52 patients with OE for culture and sensitivity. A broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of TTO for each organism.Results: In 51 per cent of the swabs taken, pathogenic organisms were cultured. Of these cultures 71 per cent, both bacteria and yeast, were susceptible to TTO 2 per cent or less. The only organism showing resistance to TTO was Pseudomonas aeruginosa; however 25 per cent of these bacteria were sensitive.Conclusion: Tea tree oil may have a role to play in the treatment of OE. However, more work needs to be done to enhance the anti-pseudomonal effect and to assess ototoxicity.
Collapse
Affiliation(s)
- T B Farnan
- Department of Otolaryngology, Craigavon Area Hospital, Northern Ireland, UK.
| | | | | | | | | |
Collapse
|
40
|
Abstract
That transport can be stressful to pigs and sheep has been inferred from behavioral and physiological measurements. Duration of journey is more likely to cause stress in pigs than in sheep, but loading and the start of travel are stressful to both. Vibration, related to vehicle design, and the jolting, shocks, and sudden impacts caused by road conditions and manner of driving, are probably of more importance than noise. Ventilation and stocking density can modulate the effects of ambient temperature, which may influence meat quality in pigs. Deprivation of food and water does not appear to stress sheep unduly, but this can become a serious welfare concern in the case of pigs. However, most journeys undertaken by pigs in the European Union are relatively short. In sheep, transport may follow soon after other stressful experiences such as weaning, shearing, handling, or marketing; the interaction of these factors in causing cumulative stress has not been studied. In pigs, fighting after the mixing of previously unacquainted animals is well known to be a welfare issue that can compromise meat quality. Considering the public interest in livestock transport and the large amounts of money involved, surprisingly little research has been done in the area, and more is urgently needed for legislation and welfare codes to be soundly based on scientific knowledge.
Collapse
Affiliation(s)
- S J Hall
- Animal Welfare and Human-Animal Interactions Group, Department of Clinical Veterinary Medicine, Cambridge, England
| | | |
Collapse
|
41
|
|
42
|
Khan A, Farnan T, Hall SJ, McClure MJ. Cervical osteophyte causing perforation of the nasopharynx. Ulster Med J 2004; 73:57-8. [PMID: 15244129 PMCID: PMC2475437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- A Khan
- Department of Otorhinolaryngology, Craigavon Area Hospital, 68 Lurgan Road, Portadown, Craigavon BT63 5QQ
| | | | | | | |
Collapse
|
43
|
Johnson CA, Pallozzi WA, Geiger L, Szumiloski JL, Castiglia L, Dahl NP, Destefano JA, Pratt SJ, Hall SJ, Beare CM, Gallagher M, Klein HJ. The effect of an environmental enrichment device on individually caged rabbits in a safety assessment facility. Contemp Top Lab Anim Sci 2003; 42:27-30. [PMID: 14510521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
The primary enclosure of a laboratory animal's environment should encourage species-typical behavior and enhancement of the animal's well-being, as indicated by the Guide. Enrichment devices have been documented to decrease the incidence of stereotypical behaviors and increase overall activity of rabbits. An 8-week study was performed to evaluate the effect of an environmental enrichment device, stainless-steel rabbit rattles on spring clips, on individually housed rabbits in a Safety Assessment facility. We used 48 New Zealand White rabbits; the devices were placed on cages of 32 study rabbits, and 16 control rabbits had no devices. Food consumption measurements and observations of device manipulations (taken during a predetermined peak interaction 1-h timeframe) were collected 5 days per week. All rabbits were bled for evaluation of hematologic parameters for the stress triad (neutrophilia, lymphopenia, and eosinopenia) and weighed weekly. No significant differences were found between study and control rabbits when body weights, food consumption, and hematologic parameters were analyzed. Our study supports previous findings that interaction with enrichment devices decreases over time, thus indicating the need for frequent rotation of different enrichment devices. In addition, no adverse effects of the analyzed parameters were found, indicating that stainless-steel rabbit rattles on spring clips are suitable devices for safety assessment studies, in which the introduction of new variables is often unacceptable.
Collapse
Affiliation(s)
- Colena A Johnson
- Department of Laboratory Animal Resources, Merck Research Laboratories, Sumneytown Pike, West Point, Pennsylvania 19486, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Laopaiboon L, Hall SJ, Smith RN. The effect of a quaternary ammonium biocide on the performance and characteristics of laboratory-scale rotating biological contactors. J Appl Microbiol 2003; 93:1051-8. [PMID: 12452962 DOI: 10.1046/j.1365-2672.2002.01785.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS To study the effect of a quaternary ammonium biocide, didecyldimethylammonium chloride (DDAC), on the treatment efficiency of laboratory-scale rotating biological contactors (RBCs) as well as their component biofilms. METHODS AND RESULTS Biofilms were established on the RBCs and then exposed to 0-160 mg l(-)1 (p.p.m.) DDAC at a flow rate of 2.5 l h(-1). The treatment efficiency of the RBC and the microbial activity of the biofilms were markedly decreased when 40 mg l(-1) DDAC or greater were applied to the units. However, DDAC had no effect on the number of viable bacteria in the biofilms when DDAC concentrations up to 80 mg l(-1) were applied to the RBCs. No viable bacteria could be detected in the biofilm when DDAC was applied at 160 mg l(-1). Extended observation over a further 40 d with 20 and 80 mg l(-1) DDAC showed similar results in terms of chemical oxygen demand removal, ATP content and viability of biofilms compared with those values over the first 12 d of exposure. CONCLUSIONS There was at least a fourfold difference in the susceptibility of planktonic and sessile bacteria to DDAC. Cells acclimatized to DDAC did not increase their capability to degrade normal carbon sources or DDAC under the conditions used in this study. SIGNIFICANCE AND IMPACT OF THE STUDY The results show that RBCs can be used to treat effluents containing DDAC at concentrations up to 20 mg l(-1) and that 160 mg l(-1) of DDAC was required to eliminate cells in established biofilms.
Collapse
Affiliation(s)
- L Laopaiboon
- Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, Thailand.
| | | | | |
Collapse
|
45
|
Laopaiboon L, Hall SJ, Smith RN. The effect of an aldehyde biocide on the performance and characteristics of laboratory-scale rotating biological contactors. J Biotechnol 2003; 102:73-82. [PMID: 12668316 DOI: 10.1016/s0168-1656(02)00358-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The effect of an aldehyde biocide, glutaraldehyde, on the treatment efficiency of laboratory-scale rotating biological contactors (RBCs) as well as their component biofilms was studied. Biofilms were established on the RBCs and then exposed to 0-120 ppm glutaraldehyde at a flow rate of 2.5 l x h(-1). The results showed that glutaraldehyde up to 80 ppm did not cause any adverse effect on chemical oxygen demand (COD) removal of the RBC units, microbial activity (ATP content) of biofilms on the RBC disc and viability of the biofilms. Glutaraldehyde at 80 ppm could be almost totally removed by the units regardless of the presence of simple carbon sources. There was at least a fourfold difference in susceptibility of planktonic and sessile bacteria to glutaraldehyde. Cells acclimatized to glutaraldehyde did not increase their capability to degrade normal carbon sources or glutaraldehyde under the conditions used in this study.
Collapse
Affiliation(s)
- L Laopaiboon
- Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand.
| | | | | |
Collapse
|
46
|
Hall SJ, Keller J, Blackall LL. Microbial quantification in activated sludge: the hits and misses. Water Sci Technol 2003; 48:121-126. [PMID: 14518863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Since the implementation of the activated sludge process for treating wastewater, there has been a reliance on chemical and physical parameters to monitor the system. However, in biological nutrient removal (BNR) processes, the microorganisms responsible for some of the transformations should be used to monitor the processes with the overall goal to achieve better treatment performance. The development of in situ identification and rapid quantification techniques for key microorganisms involved in BNR are required to achieve this goal. This study explored the quantification of Nitrospira, a key organism in the oxidation of nitrite to nitrate in BNR. Two molecular genetic microbial quantification techniques were evaluated: real-time polymerase chain reaction (PCR) and fluorescence in situ hybridisation (FISH) followed by digital image analysis. A correlation between the Nitrospira quantitative data and the nitrate production rate, determined in batch tests, was attempted. The disadvantages and advantages of both methods will be discussed.
Collapse
Affiliation(s)
- S J Hall
- School of Molecular and Microbial Sciences, The University of Queensland, St. Lucia 4072, Australia.
| | | | | |
Collapse
|
47
|
Tanaka K, Komiyama A, Sonomoto K, Ishizaki A, Hall SJ, Stanbury PF. Two different pathways for D-xylose metabolism and the effect of xylose concentration on the yield coefficient of L-lactate in mixed-acid fermentation by the lactic acid bacterium Lactococcus lactis IO-1. Appl Microbiol Biotechnol 2002; 60:160-7. [PMID: 12382058 DOI: 10.1007/s00253-002-1078-5] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2002] [Revised: 05/10/2002] [Accepted: 06/20/2002] [Indexed: 11/29/2022]
Abstract
In lactic acid bacteria, pentoses are metabolized via the phosphoketolase pathway, which catalyzes the cleavage of D-xylulose-5-phosphate to equimolar amounts of glyceraldehyde 3-phosphate and acetylphosphate. Hence the yield coefficient of lactate from pentose does not exceed 1.0 mol/mol, while that of Lactococcus lactis IO-1(JCM7638) at high D-xylose concentrations often exceeds the theoretical value. This suggests that, in addition to the phosphoketolase pathway, L. lactisIO-1 may possess another metabolic pathway that produces only lactic acid from xylose. In the present study, the metabolism of xylose in L. lactisIO-1 was deduced from the product formation and enzyme activities of L. lactisIO-1 in batch culture and continuous culture. During cultivation with xylose concentrations above ca. 50 g/l, the yield coefficient of L-lactate exceeded 1.0 mol/mol while those of acetate, formate and ethanol were very low. At xylose concentrations less than 5 g/l, acetate, formate and ethanol were produced with yield coefficients of about 1.0 mol/mol, while L-lactate was scarcely produced. In cells grown at high xylose concentrations, a marked decrease in the specific activities of phosphoketolase and pyruvate formate lyase (PFL), and an increase in those of transketolase and transaldolase were observed. These results indicate that in L. lactisIO-1 xylose may be catabolized by two different pathways, the phosphoketolase pathway yielding acetate, formate and ethanol, and the pentose phosphate (PP)/glycolytic pathway which converts xylose to L-lactate only. Furthermore, it was deduced that the change in the xylose concentration in the culture medium shifts xylulose 5-phosphate metabolism between the phosphoketolase pathway and the PP/glycolytic pathway in L. lactisIO-1, and pyruvate metabolism between cleavage to acetyl-CoA and formic acid by PFL and the reduction to L-lactate by lactate dehydrogenase.
Collapse
Affiliation(s)
- K Tanaka
- Department of Biological and Environmental Chemistry, Kyushu School of Engineering, Kinki University Kayanomori, Iizuka-si, Fukuoka 820-8555, Japan.
| | | | | | | | | | | |
Collapse
|
48
|
Abstract
The aim of this study was to assess the effect of a course of dexamethasone on postoperative pain and morbidity after adult tonsillectomy. We report the results of a double-blind, randomized, placebo-controlled trial of 200 adult patients undergoing elective tonsillectomy. Patients were randomized to three groups: one group received the non-steroidal anti-inflammatory drug piroxicam for 8 days postoperatively, one group received dexamethasone for the same period and the third group received both drugs. Patients recorded their pain scores and analgesic requirements daily for 10 days. Patients treated with a combination of piroxicam and dexamethasone recorded consistently lower pain scores than those treated with either drug alone. This difference was statistically significant (P < 0.05) on all days except the day of surgery and the second postoperative day. Patients treated with piroxicam alone had significantly higher analgesic requirements than in either of the other groups. Dexamethasone given in this regime reduces postoperative pain and analgesic requirements after adult tonsillectomy.
Collapse
Affiliation(s)
- R Stewart
- Department of Otolaryngology, Craigavon Area Hospital, Northern Ireland
| | | | | | | | | |
Collapse
|
49
|
|
50
|
Hall SJ, Canfield SE, Yan Y, Hassen W, Selleck WA, Chen SH. A novel bystander effect involving tumor cell-derived Fas and FasL interactions following Ad.HSV-tk and Ad.mIL-12 gene therapies in experimental prostate cancer. Gene Ther 2002; 9:511-7. [PMID: 11948376 DOI: 10.1038/sj.gt.3301669] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2001] [Accepted: 12/17/2001] [Indexed: 01/02/2023]
Abstract
To enhance the NK population induced by Herpes Simplex virus thymidine kinase (HSV-tk) gene transduction and ganciclovir (GCV) treatment, adenovirus-mediated (Ad) expression of IL-12 was added to Ad.HSV-tk + GCV as combination gene therapy. This approach resulted in improved local and systemic growth suppression in a metastatic model of mouse prostate cancer (RM-1). In vitro assay of tumor infiltrating lymphocytes noted superior lysis of both RM-1 and Yac-1 targets with combination therapy, but in vivo depletion of NK cells only negatively impacted on systemic growth inhibition. TUNEL assay of primary tumors noted induction of apoptosis between two and four times higher than controls lasting for 6-8 days post-vector injection. After demonstrating that Ad.HSV-tk/GCV and Ad.mIL-12-induced IFN-gamma independently up-regulated expression of FasL and Fas, respectively, studies examined tumor cell-mediated death through Fas/FasL-induced apoptosis as a mechanism of primary tumor growth suppression. In vitro, combination therapy at low vector doses resulted in synergistic growth suppression, which could be negated by the addition of anti-FasL antibody. In vivo co-inoculation of an adenovirus expressing soluble Fas resulted in combination therapy-treated tumors, which were three times larger than expected, and a reduction in apoptosis to baseline levels. In FasL knockout mice, combination therapy maintained the superior results experienced in wild-type mice, indicating that tumor cell, not host cell FasL, was responsible for Fas transactivation. Therefore, the combination of Ad.HSV-tk/GCV + Ad.mIL-12 results in enhanced local growth control via apoptosis due to tumor cell expression of Fas and FasL and improved anti-metastatic activity secondary to a strong NK response.
Collapse
Affiliation(s)
- S J Hall
- The Carl C Icahn Institute for Gene Therapy and Molecular Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA
| | | | | | | | | | | |
Collapse
|