Publications

@article{dacal2022temperature,

title = {Temperature increases soil respiration across ecosystem types and soil development, but soil properties determine the magnitude of this effect},

author = {Marina Dacal and Manuel Delgado-Baquerizo and Jes'us Barquero and Asmeret Asefaw Berhe and Antonio Gallardo and Fernando T Maestre and Pablo Garc'ia-Palacios},

year  = {2022},

date = {2022-01-01},

journal = {Ecosystems},

volume = {25},

number = {1},

pages = {184--198},

publisher = {Springer US},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{berhe2022scientists,

title = {Scientists from historically excluded groups face a hostile obstacle course},

author = {Asmeret Asefaw Berhe and Rebecca T Barnes and Meredith G Hastings and Allison Mattheis and Blair Schneider and Billy M Williams and Erika Mar'in-Spiotta},

year  = {2022},

date = {2022-01-01},

journal = {Nature Geoscience},

pages = {1--3},

publisher = {Nature Publishing Group},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{kopittke2022ensuring,

title = {Ensuring planetary survival: the centrality of organic carbon in balancing the multifunctional nature of soils},

author = {Peter M Kopittke and Asmeret Asefaw Berhe and Yolima Carrillo and Timothy R Cavagnaro and Deli Chen and Qing-Lin Chen and Mercedes Román Dobarco and Feike A Dijkstra and Damien J Field and Michael J Grundy and others},

year  = {2022},

date = {2022-01-01},

journal = {Critical Reviews in Environmental Science and Technology},

pages = {1--17},

publisher = {Taylor & Francis},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{yang2022impacts,

title = {Impacts of climate and disturbance on nutrient fluxes and stoichiometry in mixed-conifer forests},

author = {Yang Yang and Asmeret Asefaw Berhe and Carolyn T Hunsaker and Dale W Johnson and Mohammad Safeeq and Morgan E Barnes and Emma P McCorkle and Erin M Stacy and Roger C Bales and Ryan R Bart and others},

year  = {2022},

date = {2022-01-01},

journal = {Biogeochemistry},

pages = {1--20},

publisher = {Springer},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{rath2022synergy,

title = {Synergy between compost and cover crops in a Mediterranean row crop system leads to increased subsoil carbon storage},

author = {Daniel Rath and Nathaniel Bogie and Leonardo Deiss and Sanjai J Parikh and Daoyuan Wang and Samantha Ying and Nicole Tautges and Asmeret Asefaw Berhe and Teamrat A Ghezzehei and Kate M Scow},

year  = {2022},

date = {2022-01-01},

journal = {Soil},

volume = {8},

number = {1},

pages = {59--83},

publisher = {Copernicus GmbH},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Santos2021,

title = {Pyrolysis temperature and soil depth interactions determine PyC turnover and induced soil organic carbon priming},

author = {Fernanda Santos and David M. Rice and Jeffrey A. Bird and Asmeret Asefaw Berhe},

doi = {10.1007/s10533-021-00767-x},

issn = {1573515X},

year  = {2021},

date = {2021-01-01},

journal = {Biogeochemistry},

abstract = {Pyrogenic organic carbon (PyC) is a complex, heterogeneous class of thermally altered organic substrates, but its dynamics and how its behavior changes with soil depth remain poorly understood. We conducted a laboratory incubation study to investigate the interactive effects of pyrolysis temperature and soil depth on the turnover of PyC compared to its precursor wood and native SOC (NSOC). We incubated dual-labeled (13C and 15N) jack pine pyrogenic organic matter produced at 300 $,^circ$C (PyC300), 450 $,^circ$C (PyC450), and their precursor pine wood in a fine-loamy, mixed-conifer forest soil for 745 days. A mixture of surface (0--10 cm) and subsurface (50--70 cm) forest soils, with and without labeled biomass were incubated in the dark at 55% soil water field capacity and 25 $,^circ$C. Total 13C from PyC and wood mineralized as 13C-CO2 (as % of C added to soil) declined with an increase in pyrolysis temperature as follows: 54 $pm$ 7.7% for wood, 3.1 $pm$ 0.2% for PyC300, and 0.94 $pm$ 0.08% for PyC450. After 2 years, soil depth interacted with pyrolysis temperature to affect C turnover, with total wood C losses significantly declining from 70.6% in surface soils to 37.5% in subsurface soil, while total losses of PyC300 and PyC450 were unaffected by differences between surface and subsurface soils. Wood induced negative priming (i.e., decreased mineralization rates) in surface soil at days 3 and 60, while PyC300 induced positive priming (i.e., increased mineralization rates) in subsurface soil at day 60. After 2 years, unlabeled NSOC losses increased from 9.2 $pm$ 0.8% of NSOC in unamended treatments to 16.5 $pm$ 2.6% of NSOC with PyC450 additions. Our results suggest that PyC pyrolyzed at a given temperature can mineralize at similar rates between soil depths, and high amounts of PyC450 in subsurface soils can stimulate NSOC losses. These findings indicate that soil depth imposes critical controls on PyC dynamics belowground.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Min2021,

title = {Active microbial biomass decreases, but microbial growth potential remains similar across soil depth profiles under deeply-vs. shallow-rooted plants},

author = {Kyungjin Min and Eric Slessarev and Megan Kan and Karis McFarlane and Erik Oerter and Jennifer Pett-Ridge and Erin Nuccio and Asmeret Asefaw Berhe},

doi = {10.1016/j.soilbio.2021.108401},

issn = {00380717},

year  = {2021},

date = {2021-01-01},

journal = {Soil Biology and Biochemistry},

volume = {162},

abstract = {Climate-smart land management practices that replace shallow-rooted annual crop systems with deeply-rooted perennial plants can contribute to soil carbon sequestration. However, deep soil carbon accrual may be influenced by active microbial biomass and their capacity to assimilate fresh carbon at depth. Incorporating active microbial biomass, dormancy, and growth in microbially-explicit models can improve our ability to predict soil's capacity to store carbon. But, so far, the microbial parameters that are needed for such modeling are poorly constrained, especially in deep soil layers. Here, we used a lab incubation experiment and growth kinetics model to estimate how microbial parameters vary along 240 cm of soil depth in profiles under shallow- (soy) and deeply-rooted (switchgrass) plants 11 years after plant cover conversion. We also assessed resource origin and availability (total organic carbon, 14C, extractable organic carbon, specific UV absorbance of K2SO4 extractable organic C, total nitrogen, total dissolved nitrogen) along the soil profiles to examine associations between soil chemical and biological parameters. Even though root biomass was greater and rooting depth was deeper under switchgrass than soy, resource availability and microbial growth parameters were generally similar between vegetation types. Instead, depth significantly influenced soil chemical and biological parameters. For example, resource availability and total and relative active microbial biomass decreased with soil depth. Decreases in the relative active microbial biomass coincided with increased lag time (response time to external carbon inputs) along the soil profiles. Even at a depth of 210--240 cm, microbial communities were activated to grow by added resources within a day. Maximum specific growth rate decreased to a depth of 90 cm and then remained consistent in deeper layers. Our findings show that >10 years of vegetation and rooting depth changes may not be long enough to alter microbial growth parameters, and suggest that at least a portion of the microbial community in deep soils can grow rapidly in response to added resources. Our study determined microbial growth parameters that can be used in microbially-explicit models to simulate carbon dynamics in deep soil layers.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Oerter2021,

title = {Hydraulic redistribution by deeply rooted grasses and its ecohydrologic implications in the southern Great Plains of North America},

author = {Erik Oerter and Eric Slessarev and Ate Visser and Kyungjin Min and Megan Kan and Karis J. McFarlane and Malay C. Saha and Asmeret Asefaw Berhe and Jennifer Pett‐Ridge and Erin Nuccio},

doi = {10.1002/hyp.14366},

issn = {0885-6087},

year  = {2021},

date = {2021-01-01},

journal = {Hydrological Processes},

volume = {35},

issue = {9},

abstract = {Perennial bioenergy crops with deep (>1 m) rooting systems, such as switchgrass (Panicum virgatum L.), are hypothesized to increase carbon storage in deep soil. Deeply rooted plants may also affect soil hydrology by accessing deep soil water for transpiration, which can affect soil water content and infiltration in deep soil layers, thereby affecting groundwater recharge. Using stable H and O isotope (δ2H and δ18O) and 3H values, we studied the soil water conditions at 20--30 cm intervals to depths of 2.4--3.6 m in paired fields of switchgrass and shallow rooted crops at three sites in the southern Great Plains of North America. We found that soil under switchgrass had consistently higher soil water content than nearby soil under shallow-rooted annual crops by a margin of 15%--100%. Soil water content and isotopic depth profiles indicated that hydraulic redistribution of deep soil water by switchgrass roots explained these observed soil water differences. To our knowledge, these are the first observations of hydraulic redistribution in deeply rooted grasses, and complement earlier observations of dynamic soil water fluxes under shallow-rooted grasses. Hydraulic redistribution by switchgrass may be a strategy for drought avoidance, wherein the plant may actively prevent water limitation. This raises the possibility that deeply rooted grasses may be used to passively subsidize soil water to more shallow-rooted species in inter-cropping arrangements.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Yang2021,

title = {Stream Water Chemistry in Mixed-Conifer Headwater Basins: Role of Water Sources, Seasonality, Watershed Characteristics, and Disturbances},

author = {Yang Yang and Stephen C. Hart and Emma P. McCorkle and Erin M. Stacy and Morgan E. Barnes and Carolyn T. Hunsaker and Dale W. Johnson and Asmeret Asefaw Berhe},

doi = {10.1007/s10021-021-00620-0},

issn = {14350629},

year  = {2021},

date = {2021-01-01},

journal = {Ecosystems},

abstract = {Understanding the transport of dissolved organic carbon (DOC) and nitrogen (N) as water flows through headwater basins is important for predicting downstream water quality. With increased recognition of climatic impact on nutrient transport, more studies are needed in headwater basins experiencing a Mediterranean-type climate, such as those of the Sierra Nevada, California. We analyzed water samples collected over 5 years from eight low-order and mixed-conifer watersheds to elucidate the temporal variation of water chemistry and evaluate their responses to prolonged drought and low-intensity forest thinning. We observed higher stream DOC concentrations in October compared to other months within water years prior to drought and thinning, suggesting the importance of antecedent moisture conditions on seasonal C export. In unthinned watersheds, stream DOC concentrations were lower (62%) and DOC aromaticity was higher (68 and 92%, depending on the index used) during drought compared to non-drought years. In thinned watersheds during drought years, stream water had higher DOC concentrations (66--94% in three consecutive years following thinning) and dissolved inorganic N (24%, in the third year following thinning) compared to unthinned watersheds during drought. Additionally, lower stream DOC concentrations were found in watersheds with higher elevations and lower drainage densities in the year with near-average precipitation; however, these correlations were not significant in years with greater or extremely low precipitation. Taken together, our results suggest that stream concentrations of DOC and dissolved N in Mediterranean headwater basins are extremely variable over time due to the high temporal climatic variabilities and periodic management practices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Georgiou2021,

title = {Divergent controls of soil organic carbon between observations and process-based models},

author = {Katerina Georgiou and Avni Malhotra and William R. Wieder and Jacqueline H. Ennis and Melannie D. Hartman and Benjamin N. Sulman and Asmeret Asefaw Berhe and A. Stuart Grandy and Emily Kyker-Snowman and Kate Lajtha and Jessica A. M. Moore and Derek Pierson and Robert B. Jackson},

doi = {10.1007/s10533-021-00819-2},

issn = {1573515X},

year  = {2021},

date = {2021-01-01},

journal = {Biogeochemistry},

volume = {156},

issue = {1},

abstract = {The storage and cycling of soil organic carbon (SOC) are governed by multiple co-varying factors, including climate, plant productivity, edaphic properties, and disturbance history. Yet, it remains unclear which of these factors are the dominant predictors of observed SOC stocks, globally and within biomes, and how the role of these predictors varies between observations and process-based models. Here we use global observations and an ensemble of soil biogeochemical models to quantify the emergent importance of key state factors -- namely, mean annual temperature, net primary productivity, and soil mineralogy -- in explaining biome- to global-scale variation in SOC stocks. We use a machine-learning approach to disentangle the role of covariates and elucidate individual relationships with SOC, without imposing expected relationships a priori. While we observe qualitatively similar relationships between SOC and covariates in observations and models, the magnitude and degree of non-linearity vary substantially among the models and observations. Models appear to overemphasize the importance of temperature and primary productivity (especially in forests and herbaceous biomes, respectively), while observations suggest a greater relative importance of soil minerals. This mismatch is also evident globally. However, we observe agreement between observations and model outputs in select individual biomes -- namely, temperate deciduous forests and grasslands, which both show stronger relationships of SOC stocks with temperature and productivity, respectively. This approach highlights biomes with the largest uncertainty and mismatch with observations for targeted model improvements. Understanding the role of dominant SOC controls, and the discrepancies between models and observations, globally and across biomes, is essential for improving and validating process representations in soil and ecosystem models for projections under novel future conditions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{von2021continental,

title = {Continental-scale controls on soil organic carbon across sub-Saharan Africa},

author = {Sophie F Von Fromm and Alison M Hoyt and Markus Lange and Gifty E Acquah and Ermias Aynekulu and Asmeret Asefaw Berhe and Stephan M Haefele and Steve P McGrath and Keith D Shepherd and Andrew M Sila and others},

year  = {2021},

date = {2021-01-01},

journal = {Soil},

volume = {7},

number = {1},

pages = {305--332},

publisher = {Copernicus GmbH},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{billings2021soil,

title = {Soil organic carbon is not just for soil scientists: measurement recommendations for diverse practitioners},

author = {SA Billings and K Lajtha and A Malhotra and AA Berhe and M-A Graaff and S Earl and J Fraterrigo and K Georgiou and S Grandy and SE Hobbie and others},

year  = {2021},

date = {2021-01-01},

journal = {Ecological Applications},

pages = {e2290},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{yang2021stream,

title = {Stream water chemistry in mixed-conifer headwater basins: role of water sources, seasonality, watershed characteristics, and disturbances},

author = {Yang Yang and Stephen C Hart and Emma P McCorkle and Erin M Stacy and Morgan E Barnes and Carolyn T Hunsaker and Dale W Johnson and Asmeret Asefaw Berhe},

year  = {2021},

date = {2021-01-01},

journal = {Ecosystems},

volume = {24},

number = {8},

pages = {1853--1874},

publisher = {Springer US},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{berhe2021s,

title = {What's soil got to do with climate change?},

author = {Asmeret Asefaw Berhe},

year  = {2021},

date = {2021-01-01},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{georgiou2021divergent,

title = {Divergent controls of soil organic carbon between observations and process-based models},

author = {Katerina Georgiou and Avni Malhotra and William R Wieder and Jacqueline H Ennis and Melannie D Hartman and Benjamin N Sulman and Asmeret Asefaw Berhe and A Stuart Grandy and Emily Kyker-Snowman and Kate Lajtha and others},

year  = {2021},

date = {2021-01-01},

journal = {Biogeochemistry},

volume = {156},

number = {1},

pages = {5--17},

publisher = {Springer International Publishing},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{dove2021depth,

title = {Depth dependence of climatic controls on soil microbial community activity and composition},

author = {Nicholas Dove and Morgan Barnes and Kimber Moreland and Robert Graham and Asmeret Berhe and Stephen Hart},

year  = {2021},

date = {2021-01-01},

journal = {ISME Communications},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{min2021active,

title = {Active microbial biomass decreases, but microbial growth potential remains similar across soil depth profiles under deeply-vs. shallow-rooted plants},

author = {Kyungjin Min and Eric Slessarev and Megan Kan and Karis McFarlane and Erik Oerter and Jennifer Pett-Ridge and Erin Nuccio and Asmeret Asefaw Berhe},

year  = {2021},

date = {2021-01-01},

journal = {Soil Biology and Biochemistry},

volume = {162},

pages = {108401},

publisher = {Pergamon},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{mainka2021soil,

title = {Soil geochemistry as a driver of soil organic matter composition: insights from a soil chronosequence},

author = {Moritz Mainka and Laura Summerauer and Daniel Wasner and Gina Garland and Marco Griepentrog and Asmeret Asefaw Berhe and Sebastian Doetterl},

year  = {2021},

date = {2021-01-01},

journal = {Biogeosciences Discussions},

pages = {1--23},

publisher = {Copernicus GmbH},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doetterl2021preface,

title = {Preface: Tropical biogeochemistry of soils in the Congo Basin and the African Great Lakes region},

author = {Sebastian Doetterl and Marijn Bauters and Asmeret Asefaw Berhe and Pauline Chivenge and Peter Finke and Stefan Hauser},

year  = {2021},

date = {2021-01-01},

journal = {SOIL},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{moreland2021deep,

title = {Deep in the Sierra Nevada critical zone: saprock represents a large terrestrial organic carbon stock},

author = {Kimber Moreland and Zhiyuan Tian and Asmeret Asefaw Berhe and Karis J McFarlane and Peter Hartsough and Stephen C Hart and Roger Bales and Anthony T O'Geen},

year  = {2021},

date = {2021-01-01},

journal = {Environmental Research Letters},

volume = {16},

number = {12},

pages = {124059},

publisher = {IOP Publishing},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{heckman2021beyond,

title = {Beyond bulk: Density fractions explain heterogeneity in global soil carbon abundance and persistence},

author = {Katherine Heckman and Caitlin E Hicks Pries and Corey R Lawrence and Craig Rasmussen and Susan E Crow and Alison M Hoyt and Sophie F Fromm and Zheng Shi and Shane Stoner and Casey McGrath and others},

year  = {2021},

date = {2021-01-01},

journal = {Global Change Biology},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Chaudhary2020,

title = {Ten simple rules for building an antiracist lab},

author = {V. B. Chaudhary and A. A. Berhe},

doi = {10.1371/journal.pcbi.1008210},

issn = {15537358},

year  = {2020},

date = {2020-01-01},

journal = {PLoS computational biology},

volume = {16},

issue = {10},

abstract = {Demographics of the science, technology, engineering, and mathematics (STEM) workforce and student body in the US and Europe continue to show severe underrepresentation of Black, Indigenous, and people of color (BIPOC). Among the documented causes of the persistent lack of diversity in STEM are bias, discrimination, and harassment of members of underrepresented minority groups (URMs). These issues persist due to continued marginalization, power imbalances, and lack of adequate policies against misconduct in academic and other scientific institutions. All scientists can play important roles in reversing this trend by shifting the culture of academic workplaces to intentionally implement equitable and inclusive policies, set norms for acceptable workplace conduct, and provide opportunities for mentorship and networking. As scientists are increasingly acknowledging the lack of racial and ethnic diversity in science, there is a need for clear direction on how to take antiracist action. Here we present 10 rules to help labs develop antiracists policies and action in an effort to promote racial and ethnic diversity, equity, and inclusion in science.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Berhe2020,

title = {Race and racism in soil science},

author = {Asmeret Asefaw Berhe and Teamrat A. Ghezzehei},

doi = {10.1111/ejss.13078},

issn = {13652389},

year  = {2020},

date = {2020-01-01},

journal = {European Journal of Soil Science},

abstract = {Soil science is one of the least diverse fields within science, technology, engineering and mathematics (STEM). Because demographics of groups and institutions provide a window into the culture, climate, equity and inclusion of minoritized scholars, we discuss how lack of diversity continues to affect our science and the scientific community, and its implications for the welfare of the global population. We highlight the role of antiracist practices and policies for improving workplace climate and thereby developing a diverse and inclusive scientific community. We present this article as a starting point for discussions on issues of race and racism in our scientific community and institutions. Highlights: Soil science remains one of the least diverse fields in STEM. Workplace climate plays a major role in perpetuating the lack of diversity within soil science and other fields within geosciences. Incorporation of antiracist practices and policies is urgently needed to reverse the current trend and improve representation in our scientific community.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Masiello2020,

title = {First interactions with the hydrologic cycle determine pyrogenic carbon's fate in the Earth system},

author = {Caroline Ann Masiello and Asmeret Asefaw Berhe},

doi = {10.1002/esp.4925},

issn = {10969837},

year  = {2020},

date = {2020-01-01},

journal = {Earth Surface Processes and Landforms},

volume = {45},

issue = {10},

abstract = {Fires produce an aromatic particulate residue commonly referred to as pyrogenic carbon (PyC). Particulate PyC is low density, high porosity, and is predominantly deposited on the soil surface in post-fire landscapes. These characteristics create a material that is prone to mobility, both vertically down the soil profile and laterally across the landscape even in low-relief landforms. Because of its tendency for lateral mobilization, we argue here that PyC's first interaction with water determines its environmental fate and persistence, not its interactions with soil minerals or microbes. PyC's first interactions with water determine: the amount of PyC that will enter the soil profile and experience microbial and geochemical alterations, whether it will be buried in depositional environments and stored on the landscape, or if it will be transported to streams and eventually to the ocean. Here we posit that this crucial first interaction with the hydrologic cycle occurs on the timescale of days to weeks, and therefore supersedes microbial decomposition as the primary control on PyC's environmental persistence. copyright 2020 John Wiley & Sons, Ltd.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Berhe2020c,

title = {The U.S. National Committee for Soil Science: Activities, Opportunities for Service},

author = {Asmeret Asefaw Berhe and Ester Sztein and Rodrigo Vargas and Alfred E. Hartemink},

doi = {10.1002/csan.20048},

issn = {1529-9163},

year  = {2020},

date = {2020-01-01},

journal = {CSA News},

volume = {65},

issue = {2},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Lohse2020,

title = {Soil Signals Tell of Landscape Disturbances},

author = {Kathleen Lohse and Sharon Billings and Roman DiBiase and Praveen Kumar and Asmeret Berhe and Jason Kaye},

doi = {10.1029/2020eo148736},

issn = {0096-3941},

year  = {2020},

date = {2020-01-01},

journal = {Eos},

volume = {101},

abstract = {The lasting influence humans have on Earth's critical zone---and how geologic forces have mediated those influences---is revealed in studies of soil and carbon migration.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Min2020,

title = {Differential effects of wetting and drying on soil CO2 concentration and flux in near-surface vs. deep soil layers},

author = {Kyungjin Min and Asmeret Asefaw Berhe and Chau Minh Khoi and Hella Asperen and Jeroen Gillabel and Johan Six},

doi = {10.1007/s10533-020-00658-7},

issn = {1573515X},

year  = {2020},

date = {2020-01-01},

journal = {Biogeochemistry},

volume = {148},

issue = {3},

abstract = {Soil stores over 2500 Pg carbon (C), with the majority of C stored in deep soil layers (> 30 cm). Soil C can be lost to the atmosphere when organic compounds are mineralized to carbon dioxide (CO2, via oxidative decay or respiration) and moved upward through the soil profile (via diffusion). Soil moisture status can influence the balance between respiration and diffusion, thereby altering the soil CO2 concentration and flux. However, it is unclear how wetting and drying influence soil CO2 dynamics in surface vs. deep soil layers. Thus, we irrigated three soil profiles in Mediterranean arable land and continuously monitored soil CO2 concentration at 15, 30, 50, 70 and 90 cm during wetting and drying phases under ambient temperature conditions. We estimated gas diffusivity, CO2 flux, and temperature responses of soil CO2 concentration during the experiment. Decreases in gas diffusivity during the wetting period coincided with increases in soil CO2 concentrations. However, the negative gas diffusivity-soil CO2 concentration relationship did not hold true all the time, implying that CO2 production was the driving factor for the apparent soil CO2 concentration. We observed hysteretic responses of soil CO2 concentration to temperature as soil moisture varied, with deeper soil CO2 concentration being more sensitive to temperature than surface soil CO2 concentration, especially during the drying phase. The movement of CO2 was upward at all depths during the ambient phase, but the direction and the magnitude of CO2 fluxes varied across the depth gradient during the wetting and drying phases. This study highlights that the relative contribution of gas diffusivity vs. CO2 production to soil CO2 concentration changes with wetting and drying, and that the responses of soil CO2 concentration to temperature are dependent on the antecedent environmental conditions. Also, the downward movement of CO2 during the wetting and drying phases suggests that quantifying surface soil CO2 efflux may underestimate dynamic C processes in deeper soils.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Gu2020,

title = {Quantifying Uncertainties in Sequential Chemical Extraction of Soil Phosphorus Using XANES Spectroscopy},

author = {Chunhao Gu and Than Dam and Stephen C. Hart and Benjamin L. Turner and Oliver A. Chadwick and Asmeret Asefaw Berhe and Yongfeng Hu and Mengqiang Zhu},

doi = {10.1021/acs.est.9b05278},

issn = {15205851},

year  = {2020},

date = {2020-01-01},

journal = {Environmental Science and Technology},

volume = {54},

issue = {4},

abstract = {Sequential chemical extraction has been widely used to study soil phosphorus (P) dynamics and inform nutrient management, but its efficacy for assigning P into biologically meaningful pools remains unknown. Here, we evaluated the accuracy of the modified Hedley extraction scheme using P K-edge X-ray absorption near-edge structure (XANES) spectroscopy for nine carbonate-free soil samples with diverse chemical and mineralogical properties resulting from different degrees of soil development. For most samples, the extraction markedly overestimated the pool size of calcium-bound P (Ca-P, extracted by 1 M HCl) due to (1) P redistribution during the alkaline extractions (0.5 M NaHCO3 and then 0.1 M NaOH), creating new Ca-P via formation of Ca phosphates between NaOH-desorbed phosphate and exchangeable Ca2+ and/or (2) dissolution of poorly crystalline Fe and Al oxides by 1 M HCl, releasing P occluded by these oxides into solution. The first mechanism may occur in soils rich in well-crystallized minerals and exchangeable Ca2+ regardless of the presence or absence of CaCO3, whereas the second mechanism likely operates in soils rich in poorly crystalline Fe and Al minerals. The overestimation of Ca-P simultaneously caused underestimation of the pools extracted by the alkaline solutions. Our findings identify key edaphic parameters that remarkably influenced the extractions, which will strengthen our understanding of soil P dynamics using this widely accepted procedure.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Carter2020,

title = {Towards diverse representation and inclusion in soil science in the United States},

author = {Tiffany L. Carter and Lydia L. Jennings and Yamina Pressler and Adrian C. Gallo and Asmeret Asefaw Berhe and Erika Mar'in‐Spiotta and Christopher Shepard and Teamrat Ghezzehei and Karen L. Vaughan},

doi = {10.1002/saj2.20210},

issn = {0361-5995},

year  = {2020},

date = {2020-01-01},

journal = {Soil Science Society of America Journal},

abstract = {Predicting the binding mode of flexible polypeptides to proteins is an important task that falls outside the domain of applicability of most small molecule and protein−protein docking tools. Here, we test the small molecule flexible ligand docking program Glide on a set of 19 non-α-helical peptides and systematically improve pose prediction accuracy by enhancing Glide sampling for flexible polypeptides. In addition, scoring of the poses was improved by post-processing with physics-based implicit solvent MM- GBSA calculations. Using the best RMSD among the top 10 scoring poses as a metric, the success rate (RMSD ≤ 2.0 Å for the interface backbone atoms) increased from 21% with default Glide SP settings to 58% with the enhanced peptide sampling and scoring protocol in the case of redocking to the native protein structure. This approaches the accuracy of the recently developed Rosetta FlexPepDock method (63% success for these 19 peptides) while being over 100 times faster. Cross-docking was performed for a subset of cases where an unbound receptor structure was available, and in that case, 40% of peptides were docked successfully. We analyze the results and find that the optimized polypeptide protocol is most accurate for extended peptides of limited size and number of formal charges, defining a domain of applicability for this approach.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Schaefer2020,

title = {Effect of cover crop on carbon distribution in size and density separated soil aggregates},

author = {M. V. Schaefer and N. A. Bogie and D. Rath and A. R. Marklein and A. Garniwan and T. Haensel and Y. Lin and C. C. Avila and P. S. Nico and K. M. Scow and E. L. Brodie and W. J. Riley and M. L. Fogel and A. A. Berhe and T. A. Ghezzehei and S. Parikh and M. Keiluweit and S. C. Ying},

doi = {10.3390/soilsystems4010006},

issn = {25718789},

year  = {2020},

date = {2020-01-01},

journal = {Soil Systems},

volume = {4},

issue = {1},

abstract = {copyright 2020 by the authors. Licensee MDPI, Basel, Switzerland. Increasing soil organic carbon (SOC) stocks in agricultural soils can contribute to stabilizing or even lowering atmospheric greenhouse gas (GHG) concentrations. Cover crop rotation has been shown to increase SOC and provide productivity benefits for agriculture. Here we used a split field design to evaluate the short-term effect of cover crop on SOC distribution and chemistry using a combination of bulk, isotopic, and spectroscopic analyses of size-and density-separated soil aggregates. Macroaggregates (>250 µm) incorporated additional plant material with cover crop as evidenced by more negative δ13C values (−25.4%∘ with cover crop compared to −25.1%∘without cover crop) and increased phenolic (plant-like) resonance in carbon NEXAFS spectra. Iron EXAFS data showed that the Fe pool was composed of 17--21% Fe oxide with the remainder a mix of primary and secondary minerals. Comparison of oxalate and dithionite extractions suggests that cover crop may also increase Fe oxide crystallinity, especially in the dense (>2.4 g cm−3) soil fraction. Cover crop δ13C values were more negative across density fractions of bulk soil, indicating the presence of less processed organic carbon. Although no significant difference was observed in bulk SOC on a mass per mass basis between cover and no cover crop fields after one season, isotopic and spectroscopic data reveal enhanced carbon movement between aggregates in cover crop soil.},

keywords = {Aggregation, Cover crop, NEXAFS spectroscopy, Soil organic carbon},

pubstate = {published},

tppubtype = {article}

}

@article{Wieder2020,

title = {SoDaH: the SOils DAta Harmonization database, an open-source synthesis of soil data from research networks, version 1.0},

author = {William Wieder and Derek Pierson and Stevan Earl and Kate Lajtha and Sara Baer and Ford Ballantyne and Asmeret Asefaw Berhe and Sharon Billings and Laurel Brigham and Stephany Chacon and Jennifer Fraterrigo and Serita Frey and Katerina Georgiou and Marie-Anne Graaff and A. Stuart Grandy and Melannie Hartman and Sarah Hobbie and Chris Johnson and Jason Kaye and Emily Kyker-Snowman and Marcy Litvak and Michelle Mack and Avni Malhotra and Jessica Moore and Knute Nadelhoffer and Craig Rasmussen and Whendee Silver and Benjamin Sulman and Xanthe Walker and Samantha Weintraub},

doi = {10.5194/essd-2020-195},

issn = {1866-3508},

year  = {2020},

date = {2020-01-01},

journal = {Earth System Science Data Discussions},

abstract = {Data collected from research networks present opportunities to test theories and develop models about factors responsible for the long-term persistence and vulnerability of soil organic matter (SOM). Synthesizing datasets collected by different research networks presents opportunities to expand the ecological gradients and scientific breadth of information available for inquiry. Synthesizing these data, are challenging, especially considering the legacy of soils data that has already been collected and an expansion of new network science initiatives. To facilitate this effort, here we present the SOils DAta Harmonization database (SoDaH; https://lter.github.io/som-website, last accessed 15 July 2020), a flexible database designed to harmonize diverse SOM datasets from multiple research networks. SoDaH is built on several network science efforts in the United States, but the tools built for SoDaH aim to provide an open-access resource to facilitate and automate further harmonization and synthesis of soil carbon data. Moreover, SoDaH allows for individual locations to contribute results from experimental manipulations, repeated measurements from long-term studies, and local- to regional-scale gradients across ecosystems or landscapes. Finally, we also provide data visualization and analysis tools that can be used to query and analyze the aggregated database. The SoDaH v1.0 dataset is archived and available at https://doi.org/10.6073/pasta/9733f6b6d2ffd12bf126dc36a763e0b4 (Wieder et al., 2020).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Abney2019,

title = {Soil properties and combustion temperature: Controls on the decomposition rate of pyrogenic organic matter},

author = {R. B. Abney and L. Jin and A. A. Berhe},

doi = {10.1016/j.catena.2019.104127},

issn = {03418162},

year  = {2019},

date = {2019-01-01},

journal = {Catena},

volume = {182},

abstract = {copyright 2019 Elsevier B.V. Pyrogenic carbon (PyC) is the material left behind after incomplete combustion of biomass, including a spectrum of materials ranging from charcoal to lightly charred biomass. We investigated the roles of combustion temperature and properties of soil at two distinct landform positions on carbon dioxide (CO2) flux from soil and decomposition of PyC. Bark from Pinus jeffreyi was charred at three temperatures (200 $,^circ$C, 350 $,^circ$C, and 500 $,^circ$C) for an hour to create PyC before it was incubated with soil collected from eroding and depositional landform positions along the same hillslope. We determined the fraction of PyC in soil C at the beginning and end of the incubation using the Kurth-MacKenzie-Deluca digestion method. We found rates of microbial respiration in soil from the depositional landform position were over three times higher than from soil from the eroding landform position. The soil from the eroding landform position had less optimal decomposition conditions, including water holding capacity and organic matter content, compared with the soil from the depositional landform position. Furthermore, over the length of the incubation experiment, PyC concentrations decreased only in depositional soils that contained lower temperature chars, indicating that low temperature PyC has shorter residence times in soils from depositional landform positions, compared to eroding ones. Using scanning electron microscopy, we also observed physical decay of the low temperature chars. Previous research has shown that PyC is preferentially eroded from hillslopes post-fire. Here we show that erosion of PyC and deposition into depositional landform positions can cause the decay rate of PyC to significantly increase, exerting a significant control on the long-term fate of PyC in the soil system.},

keywords = {Landform position, Persistence, Pyrogenic organic matter, Soil carbon, Soil respiration},

pubstate = {published},

tppubtype = {article}

}

@article{Abney2019b,

title = {Pyrogenic carbon erosion after the Rim Fire, Yosemite National Park: The Role of Burn Severity and Slope},

author = {R. B. Abney and T. J. Kuhn and A. Chow and W. Hockaday and M. L. Fogel and A. A. Berhe},

doi = {10.1029/2018JG004787},

issn = {21698961},

year  = {2019},

date = {2019-01-01},

journal = {Journal of Geophysical Research: Biogeosciences},

volume = {124},

issue = {2},

abstract = {copyright2019. American Geophysical Union. All Rights Reserved. Pyrogenic carbon (PyC) is an incomplete combustion by-product with longer soil residence times compared with nonpyrogenic components of the soil carbon (C) pool and can be preferentially eroded in fire-affected landscapes. To investigate geomorphic and fire-related controls on PyC erosion, sediment fences were established in three combinations of slope (high 13.9--37.3%; moderate 0--6.7%) and burn severity (high; moderate) plots within the perimeter of the Rim Fire in 2013, Yosemite National Park, California, USA. After each major precipitation event following the fire, we determined transport rates of total sediment, fine and coarse sediment fractions, and C and nitrogen (N). We measured stable isotope (δ13C and δ15N) compositions and 13C-nuclear magnetic resonance spectra of soils and eroded sediments. The highest total and fine (<2 mm) sediment transport in high severity burned areas correlated with initial discharge peaks from an adjacent stream, while moderate burn severity sites had considerably more of the >2 mm fraction transported than high burn severity sites. The δ13C and δ15N values and 13C-nuclear magnetic resonance analyses indicated that sediment eroded from moderate severity burn areas included fresh organic matter that was not as significantly affected by the fire, whereas sediments from high severity burn areas were preferentially enriched in PyC. Our results indicate that along a single hillslope after the Rim Fire, burn severity acted as a primary control on PyC transport postfire, with slope angle likely playing a secondary role. The preferential erosion of PyC has major implications for the long-term persistence of PyC within the soil system.},

keywords = {Black carbon, organic matter, sediment, Wildfire},

pubstate = {published},

tppubtype = {article}

}

@article{Stacy2019,

title = {Stabilization Mechanisms and Decomposition Potential of Eroded Soil Organic Matter Pools in Temperate Forests of the Sierra Nevada, California},

author = {E. M. Stacy and A. A. Berhe and C. T. Hunsaker and D. W. Johnson and S. M. Meding and S. C. Hart},

doi = {10.1029/2018JG004566},

issn = {21698961},

year  = {2019},

date = {2019-01-01},

journal = {Journal of Geophysical Research: Biogeosciences},

volume = {124},

issue = {1},

abstract = {copyright2018. American Geophysical Union. All Rights Reserved. The lateral destination and potential decomposition of soil organic matter mobilized by soil erosion depends on factors such as the amount and type of precipitation, topography, the nature of mobilized organic matter (OM), potential mixing with mineral particles, and the stabilization mechanisms of the soil OM. This study examined how the relative distribution of carbon (C) and nitrogen (N) in different OM fractions varied in soils from eroding slopes and in eroded sediments in a series of low-order forested catchments in the western Sierra Nevada, California. We found that precipitation amount played a major role in mobilizing OM. More than 40% of the OM exported from these forested catchments was free particulate OM, or OM physically protected inside relatively less stable macroaggregates, compared to OM inside microaggregates or chemically associated with soil minerals. Years with high amounts of precipitation generally transported more mineral-associated OM, with lower C and N concentrations, while sediment transported in drier years was more enriched in unprotected, coarse particulate OM derived from surficial soils. When incubated under the same conditions, sediment C (from material captured in settling basins) produced 72--97% more CO 2 during decomposition than soil C did. Our results suggest that without stabilization through burial or reconfigured organomineral associations, this sediment OM is prone to decomposition, which may contribute to little to no terrestrial CO 2 sink induced from erosion in these Mediterranean montane forest ecosystems.},

keywords = {Erosion, montane, Soil organic matter, Stabilization, temperate coniferous forests},

pubstate = {published},

tppubtype = {article}

}

@article{Santos2019b,

title = {Fire severity, time since fire, and site-level characteristics influence streamwater chemistry at baseflow conditions in catchments of the Sierra Nevada, California, USA},

author = {F. Santos and A. S. Wymore and B. K. Jackson and S. M. P. Sullivan and W. H. McDowell and A. A. Berhe},

doi = {10.1186/s42408-018-0022-8},

issn = {19339747},

year  = {2019},

date = {2019-01-01},

journal = {Fire Ecology},

volume = {15},

issue = {1},

abstract = {copyright 2019, The Author(s). Background: Fire plays an important role in controlling the cycling and composition of organic matter and nutrients in terrestrial and aquatic ecosystems. In this study, we investigated the effects of wildfire severity, time since fire, and site-level characteristics on (1) concentration of multiple solutes (dissolved organic carbon, DOC; total dissolved nitrogen, TDN; dissolved organic nitrogen, DON; calcium, Ca2+; magnesium, Mg2+; potassium, K+; sodium, Na+; chloride, Cl−; nitrate, NO3−; ammonium, NH4+; sulfate, SO42−; and phosphate, PO43−), and (2) the molecular composition of stream-dissolved organic matter (DOM) across 12 streams sampled under baseflow conditions in Yosemite National Park, California, USA. Samples were collected from low- and high-severity burned stream reaches, as well as an unburned reference stream reach. Results: Fire severity, time since fire, and variability in site-level characteristics emerged as the strongest influences on streamwater chemistry. Results from mixed-effect models indicated that DOC and DON concentrations decreased with time since fire in high-severity burned stream reaches. In low-severity burned stream reaches, DOC concentrations increased, and DON concentrations slightly decreased with time since fire. We also found that declines in aromaticity (expressed as decreased SUVA254) and mean molecular weight DOM (expressed as increased E2:E3 ratios) with time since fire were associated with high-severity fires. Mixed-effect models also indicated that site-level characteristics played a role in solute responses. Aliphatic structures dominated streamwater DOM composition across fire-impacted catchments, but neither fire severity nor time since fire was a significant predictor of the proportion of aliphatic structures in streamwater DOM. North aspect exhibited the highest concentrations of Ca2+, K+, and Mg2+, whereas the north-northwest aspect exhibited the highest concentrations of Cl− and SO42+. We also observed elevated Ca2+, K+, and Mg2+ in burned (but not reference) stream reaches with pool-riffle versus step-pool bed morphology. Conclusions: Taken together, our findings suggest that the response of stream chemistry to wildfires in the Sierra Nevada, California, can persist for years, varying with both fire severity and site-specific characteristics. These impacts may have important implications for biogeochemical cycles and productivity in aquatic ecosystems in fire-adapted landscapes.},

keywords = {1H-NMR, aromaticity, catchment, dissolved organic carbon, fire severity, Sierra Nevada, solute chemistry, streamwater, time since fire, Wildfire},

pubstate = {published},

tppubtype = {article}

}

@article{Stutz2019,

title = {Lignin from white-rotted European beech deadwood and soil functions},

author = {K. P. Stutz and K. Kaiser and J. Wambsganss and F. Santos and A. A. Berhe and F. Lang},

doi = {10.1007/s10533-019-00593-2},

issn = {1573515X},

year  = {2019},

date = {2019-01-01},

journal = {Biogeochemistry},

volume = {145},

issue = {1-2},

abstract = {copyright 2019, Springer Nature Switzerland AG. In forest ecosystems, deadwood can improve carbon storage, nutrient availability, and water holding capacity in soils. Yet the effect of organic matter from deadwood such as lignin on these soil functions and their regulators are unknown. We hypothesized that carbon storage, exchangeable cations, and pore space increase with the quantity of lignin-derived phenolic acids from beech deadwood. We also hypothesize that the most pronounced differences occur in more advanced decay classes, in the forest floor at sites with moder forest floors, and in the Ah horizon at sites with mull forest floors. Cupric oxide-oxidation products were used to determine lignin concentration, composition, and oxidation from paired reference and test samples next to 42 downed European beech (Fagus sylvatica L.) deadwood logs in ten stands in Southwest Germany. Compared to reference points, the sum of vanillyl, syringyl and cinnamyl lignin-derived phenols increased next to beech deadwood (within 10--20 cm). The composition and oxidation of lignin-derived phenols also changed near beech deadwood: syringyl/vanillyl ratios increased while cinnamyl/vanillyl and aldehyde/acid ratios for vanillyl decreased. Water-extractable organic carbon (OC) and its aromaticity also increased next to beech deadwood as did total OC and particulate OC separated by density fractionation relative to total and mineral-bound OC. These changes occurred namely in the organic horizons of moder forest floors, and in the Ah horizon underneath mull forest floors. These observations indicated that phenols predominantly entered soil in fluxes of fragmented and dissolved organic matter from beech deadwood. Changes to soil nutrient availability and porosity were linked to increasing lignin-derived phenols from beech deadwood especially in nutrient-poor soils and near heavily decayed deadwood. This is evidence that soils close to beech deadwood, a substrate, are spatially limited pedogenic hot-spots that have increased soil carbon, available nutrients, and pore space depending on the forest floor and parent material.},

keywords = {1H-NMR, Coarse woody debris, CuO-oxidation, Density fractionation, Fagus sylvatica, Soil organic matter},

pubstate = {published},

tppubtype = {article}

}

@article{Ghezzehei2019,

title = {On the role of soil water retention characteristic on aerobic microbial respiration},

author = {Teamrat A. Ghezzehei and Benjamin Sulman and Chelsea L. Arnold and Nathaniel A. Bogie and Asmeret Asefaw Berhe},

doi = {10.5194/bg-16-1187-2019},

issn = {17264189},

year  = {2019},

date = {2019-01-01},

journal = {Biogeosciences},

volume = {16},

issue = {6},

abstract = {Soil water status is one of the most important environmental factors that control microbial activity and rate of soil organic matter (SOM) decomposition. Its effect can be partitioned into effect of water energy status (water potential) on cellular activity, effect of water volume on cellular motility, and aqueous diffusion of substrate and nutrients, as well as the effect of air content and gas-diffusion pathways on concentration of dissolved oxygen. However, moisture functions widely used in SOM decomposition models are often based on empirical functions rather than robust physical foundations that account for these disparate impacts of soil water. The contributions of soil water content and water potential vary from soil to soil according to the soil water characteristic (SWC), which in turn is strongly dependent on soil texture and structure. The overall goal of this study is to introduce a physically based modeling framework of aerobic microbial respiration that incorporates the role of SWC under arbitrary soil moisture status. The model was tested by comparing it with published datasets of SOM decomposition under laboratory conditions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Liu2019,

title = {Characterizing dissolved organic matter in eroded sediments from a loess hilly catchment using fluorescence EEM-PARAFAC and UV--Visible absorption: Insights from source identification and carbon cycling},

author = {C. Liu and Z. Li and A. A. Berhe and H. Xiao and L. Liu and D. Wang and H. Peng and G. Zeng},

doi = {10.1016/j.geoderma.2018.07.029},

issn = {00167061},

year  = {2019},

date = {2019-01-01},

journal = {Geoderma},

volume = {334},

abstract = {copyright 2018 Elsevier B.V. The chemical characteristics of dissolved organic matter (DOM) in soils that experience erosion and deposition are key to the biogeochemical cycle of carbon on the earth's surface. However, data related to the transport and fate of DOM from soils that experience erosion and different management practices are scarce, particularly at catchment scales. In this study, soil samples (uppermost 10 cm) were collected from uplands representing four land use types (cropland, fallow, grassland, and forests) as well as gullies, and sediment samples (100 cm sampled at 10 depths) were collected from sediments retained by a check dam. Chemical characteristics of DOM in soils and sediments, as well as subsequent source identification, were inferred from UV--Visible absorption and fluorescence excitation emission matrix (EEM)-parallel factor analysis (PARAFAC) as well as principal component analysis (PCA). The results indicated higher aromaticity, hydrophobic fraction, and molecular size in DOM from forest soils than those from other land use types and gullies. These factors were also higher in soils at the eroding sites than in sediments. EEM-PARAFAC analysis demonstrated that more protein-like components (tyrosine-like and tryptophan-like combined, accounting for >42.77%) were present in sediments compared to soils with terrestrial humic-like substances. PCA results revealed that approximately 72% of the variance in the DOM characteristics was explained by the first two principal components and that the DOM in upland and gully soils had a negligible contribution to DOM in sediments. Combined our results indicate that, despite the large amount of sediment-associated carbon that is transported by erosion and trapped in check dams, DOM is likely mineralized during soil transport. Furthermore, biological production of new organic compounds (autochthonous sources) are likely the major source of sediment DOM in depositional settings.},

keywords = {Dissolved organic matter, Fluorescence, Land use types, Soil erosion, Source fingerprinting},

pubstate = {published},

tppubtype = {article}

}

@article{Liu2019b,

title = {Chemical characterization and source identification of organic matter in eroded sediments: Role of land use and erosion intensity},

author = {C. Liu and Z. Li and A. A. Berhe and G. Zeng and H. Xiao and L. Liu and D. Wang and H. Peng},

doi = {10.1016/j.chemgeo.2018.12.040},

issn = {00092541},

year  = {2019},

date = {2019-01-01},

journal = {Chemical Geology},

volume = {506},

abstract = {copyright 2019 Elsevier B.V. Soil erosion is a key variable in the biogeochemical cycle of carbon (C) on the Earth's surface. However, questions remain about the roles of land use and erosion intensity on the composition, source, and fate of soil C eroded from terrestrial to fluvial systems. In this study, chemical characteristics of eroded water-extractable organic matter (WEOM) in soils and sediments, as well as subsequent source identification, were inferred from UV--Visible absorption and fluorescence excitation emission matrix (EEM)-parallel factor analysis (PARAFAC) in study sites that include land uses and gully banks, experiencing three levels of erosion intensity in a semi-arid region of China. 13 C and 15 N isotopic signatures along with elemental ratios were also successfully employed to explore the source of bulk soil organic matter (SOM) in sediments. We found a much greater contribution of condensed aromatic structures and hydrophobic fraction of soluble organic compounds in forest soils compared to croplands at eroding sites, where these variables were greater than those of depositional sites. The results from fluorescence analysis in soil materials showed that erosion intensity has a negligible influence on WEOM quality. The EEM-PARAFAC with fluorescence indices indicated that biological production of soil substrates can also play a key role in the dynamics of WEOM induced by soil erosion. Our results from an isotopic mixing model analysis showed that gully bank soil was the primary sources of sedimentary SOM in all regions with different erosion intensities (mean probability estimate (MPE) 100% for the region with light erosion intensity, 36.18% for the region with high erosion intensity, and 99.25% for the region with extremely high erosion intensity). However, orchard and grassland were also the main contributors for the SOM in sediments in regions with high erosion intensity, accounting for MPE 29.93% and 33.89%, respectively. Our findings demonstrate that land use and erosion intensity have significant effect on nature of eroded OM.},

keywords = {Fate of eroded OM, Land use, Soil erosion, Source fingerprinting},

pubstate = {published},

tppubtype = {article}

}

@article{Vaughan2019,

title = {Women in Soil Science: Growing Participation, Emerging Gaps, and the Opportunities for Advancement in the USA},

author = {K. Vaughan and H. Van Miegroet and A. Pennino and Y. Pressler and C. Duball and E. C. Brevik and A. A. Berhe and C. Olson},

doi = {10.2136/sssaj2019.03.0085},

issn = {14350661},

year  = {2019},

date = {2019-01-01},

journal = {Soil Science Society of America Journal},

volume = {83},

issue = {5},

abstract = {copyright 2019 The Authors. Core Ideas Despite historic gains, women remain under-represented in soils-related careers. Women are under-represented in soil science leadership positions. Women receive SSSA awards at lower rates than their participation in the society. Women face attrition more than men as they advance the soil science career ladder. Diversity and inclusion are important pathways to grow and innovate soil science. The soil science discipline has undergone significant changes since its establishment in the 1900s; from strong connections with agronomy to a broader focus on ecosystems, earth, and environmental sciences while also during this period experiencing a notable increase in diversity among soil scientists. In this review, we explore soil science from the perspective of gender demographics and disciplinary foci of soil scientists. We examine graduate student enrollment metrics; employment information in academia, the federal government, and the private sector; and membership data from SSSA to gain deeper insight into these changes and the implications for the future of soil science. Women earn nearly half of the advanced soil science degrees. The number of women pursuing soil science careers has also increased, albeit less markedly, as women now comprise 24, 26, and 20% of the soil scientists in academic faculty positions, federal agencies, and private industry, respectively. However, there is reason for concern that women linger in intermediate levels of employment, and further attrition occurs along the career ladder with only ∼18% of the highest employment levels held by women; even fewer reach executive leadership levels in any sector. The growing participation of women in soil science is further reflected in a nearly 45% increase in female membership and meeting attendance in SSSA over the past decade, but recognition of their accomplishments and their presence in SSSA leadership positions remains low. We provide recommendations toward greater inclusion and gender diversity as this represents an important pathway to grow and innovate our science.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Finke2019,

title = {Can SOC modelling be improved by accounting for pedogenesis?},

author = {P. Finke and E. Opolot and J. Balesdent and A. A. Berhe and P. Boeckx and S. Cornu and J. Harden and C. Hatté and E. Williams and S. Doetterl},

doi = {10.1016/j.geoderma.2018.10.018},

issn = {00167061},

year  = {2019},

date = {2019-01-01},

journal = {Geoderma},

volume = {338},

abstract = {copyright 2018 Elsevier B.V. Recent findings suggest that soil organic carbon mineralization and stabilization depend to a substantial degree on the soil geochemistry and the degree of weathering. We hypothesized that this dependence can be translated to decay rate modifiers in a model context, and used data from the Merced chronosequence (CA, U.S.A., 100 yr--3 Myr), representing a weathering sequence, to test, on a 1000-year time scale for model spin-up, a simple soil organic carbon (SOC) model based on the RothC26.3 model concepts. Model performance was tested for four levels of information: (1) known decay rates for each model SOC pool at individual chronosequence locations, obtained by calibrating the model to measured SOC-fractions and measured site-specific C-inputs; (2) average decay rates for each SOC-pool, corrected per location with rate modifiers based on geochemical proxies and measured site-specific C-inputs; (3) uncorrected average decay rates per SOC-pool and measured site-specific C-inputs; (4) uncorrected average decay rates per SOC-pool and averaged C-inputs. A lumped root mean square error (RMSE) statistic was calculated for each information level. We found that using local measurements of fresh C-input led to a decrease in RMSE of near 15% relative to information level (4). Applying geochemical rate modifiers led to a further reduction of 20%. Thus, we conclude that there is a benefit of including geochemical rate modifiers in this SOC-model. We repeated this analysis for a five-pool and a four-pool SOC model that either included or excluded an inert organic matter pool. In terms of the lumped RMSE both models performed similarly, but by comparing measured and simulated percentage Modern Carbon (pMC) for bulk SOC we concluded that measured pMC was best approximated using a four-pool SOC model (without an Inert Organic Matter pool). Furthermore, it is likely that a five-pool model including a very slowly decaying pool would further improve model performance.},

keywords = {Chronosequence, Modelling, Pedogenesis, Soil organic carbon, Weathering},

pubstate = {published},

tppubtype = {article}

}