Mark's research expertise is in soil microbial ecology and biogeochemistry in response to global change phenomenon. He leads a team focused on studies of microbial, chemical, and biophysical controls on carbon cycling in permafrost, boreal, and wetland ecosystems of Alaska as well as forest and grassland ecosystems of the Western U.S.
Synergistic Activities
USGS Menlo Park Science Advisory Council Member
US Permafrost Association President
Affiliate/Graduate Faculty, University of Alaska Fairbanks & University of Guelph
Bonanza Creek LTER and Alaska Peatland Experiment (APEX), Principal Investigator
International Soil Carbon Network (NSCN) member
Integrated Ecosystem Model data contributor, AK Climate Science Center
Permafrost Research Coordination Network contributor
Environmental Microbiome Project (EMP) member
North American Carbon Program (NACP), affiliated project lead
Professional Experience
2013- current Project Chief, Mechanisms of Soil Carbon Sequestration
2007- current Research Soil Scientist, USGS, Menlo Park, CA.
2005-2007 Mendenhall Research Fellow, USGS, Menlo Park, CA.
2002-2004 Postdoctoral Fellow, The University of Michigan
Education and Certifications
2002-University of California at Berkeley, Ph.D., Soil Science
1997-University of California at Berkeley, M.S., Soil Science
1995-New Mexico State Univ, B.S. Biology/Ecology, and B.S. Soil Science
Science and Products
Below are Mark's related science projects
Response of plant, microbial, and soil functions to drought and fire in California
Understanding Impacts of Sea-Level Rise and Land Management on Critical Coastal Marsh Habitat
Arctic Biogeochemical Response to Permafrost Thaw (ABRUPT)
Understanding Impacts of Sea-Level Rise and Land Management on Critical Coastal Marsh Habitat
Next Generation of Ecological Indicators: Defining Which Microbial Properties Matter Most to Ecosystem Function and How to Measure Them
Understanding the Impacts of Permafrost Change: Providing Input into the Alaska Integrated Ecosystem Model
Spatiotemporal dynamics of soil carbon following coastal wetland loss at a Louisiana coastal salt marsh in the Mississippi River Deltaic Plain in 2019
Permafrost greenhouse gas and microbial data from the Alaska Peatland Experiment (APEX) 2017 to 2019
Permafrost characterization at the Alaska Peatland Experiment (APEX) site: Geophysical and related field data collected from 2018-2020
Flux and Soil Data from the Alaska Peatland Experiment 2014 to 2016
Microbial Carbon and Nitrogen Metabolism Across a Late Pleistocene Permafrost Chronosequence
Permafrost Mapping in Two Wetland Systems North of the Tanana River in Interior Alaska 2014
Batch sorption data, respired CO2, extractable DOC, and Raman spectra collected from an incubation with microbial necromass on feldspar or amorphous aluminum hydroxide
Dissolved organic carbon and nitrogen release from boreal Holocene permafrost and seasonally frozen soils of Alaska
Below are Mark's related publication
A model of the spatiotemporal dynamics of soil carbon following coastal wetland loss applied to a Louisiana salt marsh in the Mississippi River Deltaic Plain
Mechanisms for retention of low molecular weight organic carbon varies with soil depth at a coastal prairie ecosystem
Influence of permafrost type and site history on losses of permafrost carbon after thaw
The biophysical role of water and ice within permafrost nearing collapse: Insights from novel geophysical observations
Carbon fluxes and microbial activities from boreal peatlands experiencing permafrost thaw
USGS permafrost research determines the risks of permafrost thaw to biologic and hydrologic resources
Permafrost mapping with electrical resistivity tomography in two wetland systems north of the Tanana River, Interior Alaska
Getting to the root of plant‐mediated methane emissions and oxidation in a thermokarst bog
Generalized models to estimate carbon and nitrogen stocks of organic soil horizons in Interior Alaska
Life at the frozen limit: Microbial carbon metabolism across a Late Pleistocene permafrost chronosequence
Soil microbial communities and global change
Large loss of CO2 in winter observed across pan-arctic permafrost region
Science and Products
- Science
Below are Mark's related science projects
Response of plant, microbial, and soil functions to drought and fire in California
California is experiencing changes in precipitation and wildfire regimes. Longer, hotter fire seasons along with extremes in precipitation are expected to continue. Not only do these disturbances affect the productivity and resilience of ecosystems, they also directly impact human health and wellbeing. Soils hold an immense amount of our terrestrial carbon pool, and the microorganisms and minerals...Understanding Impacts of Sea-Level Rise and Land Management on Critical Coastal Marsh Habitat
To ensure successful restoration of coastal wetlands, WARC researchers will measure carbon cycling processes that indicate ecosystem health and sustainability.Arctic Biogeochemical Response to Permafrost Thaw (ABRUPT)
Warming and thawing of permafrost soils in the Arctic is expected to become widespread over the coming decades. Permafrost thaw changes ecosystem structure and function, affects resource availability for wildlife and society, and decreases ground stability which affects human infrastructure. Since permafrost soils contain about half of the global soil carbon (C) pool, the magnitude of C losses...Understanding Impacts of Sea-Level Rise and Land Management on Critical Coastal Marsh Habitat
The Science Issue and Relevance: Coastal wetlands are some of the most productive and valuable habitats in the world. Louisiana contains 40% of the United States’ coastal wetlands, which provide critical habitat for waterfowl and fisheries, as well as many other benefits, such as storm surge protection for coastal communities. In terms of ecosystem services, biological resource production, and inf...Next Generation of Ecological Indicators: Defining Which Microbial Properties Matter Most to Ecosystem Function and How to Measure Them
While it is widely recognized that microorganisms are intimately linked with every biogeochemical cycle in all ecosystems, it is not clear how and when microbial dynamics constrain ecosystem processes. As a result, it is know clear how to apply the value of increasingly detailed characterization of microbial properties to our understanding of ecosystem ecology. Several recent papers have demonstraUnderstanding the Impacts of Permafrost Change: Providing Input into the Alaska Integrated Ecosystem Model
Ongoing climate change has the potential to negatively impact Alaska’s ecosystems and the critical services that they provide. These ecosystem services include supplying food and fiber for Alaskan communities, offering opportunities for recreational, cultural, and spiritual activities, and regulating temperature and water flow (runoff, flooding, etc.). Scientists build models to better understan - Data
Spatiotemporal dynamics of soil carbon following coastal wetland loss at a Louisiana coastal salt marsh in the Mississippi River Deltaic Plain in 2019
This dataset provides the water content, bulk density, carbon concentrations, nitrogen concentrations, and carbon content of all fourteen cores sampled in coastal Louisiana (CRMS 0224) in October of 2019. Each sample is identified by a unique identifier that corresponds to each site by depth increment combination. The pond age range associated with each site is provided. The depth increment associPermafrost greenhouse gas and microbial data from the Alaska Peatland Experiment (APEX) 2017 to 2019
These data include permafrost gas concentration data from the Alaska Peatland Experiment at various depths, times, and locationsPermafrost characterization at the Alaska Peatland Experiment (APEX) site: Geophysical and related field data collected from 2018-2020
Geophysical measurements and related field data were collected by the U.S. Geological Survey (USGS) at the Alaska Peatland Experiment (APEX) site in Interior Alaska from 2018 to 2020 to characterize subsurface thermal and hydrologic conditions along a permafrost thaw gradient. The APEX site is managed by the Bonanza Creek LTER (Long Term Ecological Research). In April 2018, seven boreholes were emFlux and Soil Data from the Alaska Peatland Experiment 2014 to 2016
This dataset supports a published study on the effects of permafrost thaw on greenhouse gas fluxes and microbial activities at the Alaska Peatland Experiment (APEX), part of the Bonanza Creek LTER, in interior Alaska. The dataset includes autochamber CO2 and CH4 fluxes, net ecosystem exchange, ecosystem respiration, soil temperatures, climate data, microbial qPCR data, soil physical chemistry, soiMicrobial Carbon and Nitrogen Metabolism Across a Late Pleistocene Permafrost Chronosequence
This data release includes all of the data presented in the peer-reviewed publication "Life at the frozen limit: Microbial Carbon Metabolism Across a Late Pleistocene Permafrost Chronosequence". We collected permafrost from a Pleistocene chronosequence (19 ka to 33 ka) to examine (1) changes in the functional genetic potential of extant microbial communities to metabolize polysaccharides, (2) shifPermafrost Mapping in Two Wetland Systems North of the Tanana River in Interior Alaska 2014
Surface-based 2D electrical resistivity tomography (ERT) surveys were used to investigate the distribution of permafrost at wetland sites on the alluvial plain north of the Tanana River, 20 km southwest of Fairbanks, Alaska, in June and September 2014. The sites contained habitat types characteristic of interior Alaska, including thermokarst bog, forested permafrost plateau, and a rich fen. TheseBatch sorption data, respired CO2, extractable DOC, and Raman spectra collected from an incubation with microbial necromass on feldspar or amorphous aluminum hydroxide
These datasets are from an incubation experiment with a combination of two minerals (feldspar or amorphous aluminum hydroxide), one living species of bacteria (Escherichia coli), and one added form of C (Arthrobacter crystallopoietes necromass). We characterized the sorptive properties of the minerals with batch sorption experiments using four low molecular weight C substrates (glucose, oxalic aciDissolved organic carbon and nitrogen release from boreal Holocene permafrost and seasonally frozen soils of Alaska
Permafrost (perennially frozen) and active-layer (seasonally thawed) soils varying in soil carbon (C) and nitrogen (N) content and radiocarbon age were collected from three sites in interior Alaska to determine potential release of dissolved organic carbon (DOC), total dissolved N (TDN), dissolved organic nitrogen (DON), and dissolved inorganic nitrogen (DIN) upon thaw. Soil cores were cut into 15 - Publications
Below are Mark's related publication
Filter Total Items: 37A model of the spatiotemporal dynamics of soil carbon following coastal wetland loss applied to a Louisiana salt marsh in the Mississippi River Deltaic Plain
The potential for carbon sequestration in coastal wetlands is high due to protection of carbon (C) in flooded soils. However, excessive flooding can result in the conversion of the vegetated wetland to open water. This transition results in the loss of wetland habitat in addition to the potential loss of soil carbon. Thus, in areas experiencing rapid wetland submergence, such as the Mississippi RiMechanisms for retention of low molecular weight organic carbon varies with soil depth at a coastal prairie ecosystem
Though primary sources of carbon (C) to soil are plant inputs (e.g., rhizodeposits), the role of microorganisms as mediators of soil organic carbon (SOC) retention is increasingly recognized. Yet, insufficient knowledge of sub-soil processes complicates attempts to describe microbial-driven C cycling at depth as most studies of microbial-mineral-C interactions focus on surface horizons. We leveragInfluence of permafrost type and site history on losses of permafrost carbon after thaw
We quantified permafrost peat plateau and post-thaw carbon (C) stocks across a chronosequence in Interior Alaska to evaluate the amount of C lost with thaw. Macrofossil reconstructions revealed three stratigraphic layers of peat: (1) a base layer of fen/marsh peat, (2) peat from a forested peat plateau (with permafrost) and, (3) collapse-scar bog peat (at sites where permafrost thaw has occurred).The biophysical role of water and ice within permafrost nearing collapse: Insights from novel geophysical observations
The impact of permafrost thaw on hydrologic, thermal, and biotic processes remains uncertain, in part due to limitations in subsurface measurement capabilities. To better understand subsurface processes in thermokarst environments, we collocated geophysical and biogeochemical instruments along a thaw gradient between forested permafrost and collapse-scar bogs at the Alaska Peatland Experiment (APECarbon fluxes and microbial activities from boreal peatlands experiencing permafrost thaw
Permafrost thaw in northern ecosystems may cause large quantities of carbon (C) to move from soil to atmospheric pools. Because soil microbial communities play a critical role in regulating C fluxes from soils, we examined microbial activity and greenhouse gas production soon after permafrost thaw and ground collapse (into collapse-scar bogs), relative to the permafrost plateau or older thaw featuUSGS permafrost research determines the risks of permafrost thaw to biologic and hydrologic resources
The U.S. Geological Survey (USGS), in collaboration with university, Federal, Tribal, and independent partners, conducts fundamental research on the distribution, vulnerability, and importance of permafrost in arctic and boreal ecosystems. Scientists, land managers, and policy makers use USGS data to help make decisions for development, wildlife habitat, and other needs. Native villages and citiesByNatural Hazards, Water Resources, Earth Resources Observation and Science Center, Climate Research and Development Program, Coastal and Marine Hazards and Resources Program, Land Change Science Program, Volcano Hazards, Earth Resources Observation and Science (EROS) Center , Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center, Pacific Coastal and Marine Science Center, Volcano Science CenterPermafrost mapping with electrical resistivity tomography in two wetland systems north of the Tanana River, Interior Alaska
Surface-based 2D electrical resistivity tomography (ERT) surveys were used to characterize permafrost distribution at wetland sites on the alluvial plain north of the Tanana River, 20 km southwest of Fairbanks, Alaska, in June and September 2014. The sites were part of an ecologically-sensitive research area characterizing biogeochemical response of this region to warming and permafrost thaw, andGetting to the root of plant‐mediated methane emissions and oxidation in a thermokarst bog
Vascular plants are important in the wetland methane cycle, but their effect on production, oxidation, and transport has high uncertainty, limiting our ability to predict emissions. In a permafrost‐thaw bog in Interior Alaska, we used plant manipulation treatments, field‐deployed planar optical oxygen sensors, direct measurements of methane oxidation, and microbial DNA analyses to disentangle mechGeneralized models to estimate carbon and nitrogen stocks of organic soil horizons in Interior Alaska
Boreal ecosystems comprise one tenth of the world’s land surface and contain over 20 % of the global soil carbon (C) stocks. Boreal soils are unique in that its mineral soil is covered by what can be quite thick layers of organic soil. These organic soil layers, or horizons, can differ in their state of decomposition, source vegetation, and disturbance history. These differences result in varyingLife at the frozen limit: Microbial carbon metabolism across a Late Pleistocene permafrost chronosequence
Permafrost is an extreme habitat yet it hosts microbial populations that remain active over millennia. Using permafrost collected from a Pleistocene chronosequence (19 to 33 ka), we hypothesized that the functional genetic potential of microbial communities in permafrost would reflect microbial strategies to metabolize permafrost soluble organic matter (OM) in situ over geologic time. We also hypoSoil microbial communities and global change
Soils and soil microbial communities mediate the biogeochemical processes that underly ecosystem-level changes. This chapter examines why soils and soil microbial communities are important for understanding impacts and feedbacks to global change. It discusses the technological approaches and challenges that are at the frontiers of this research area. Global change impacts on microbial communitiesLarge loss of CO2 in winter observed across pan-arctic permafrost region
Recent warming in the Arctic, which has been amplified during the winter1,2,3, greatly enhances microbial decomposition of soil organic matter and subsequent release of carbon dioxide (CO2)4. However, the amount of CO2 released in winter is not known and has not been well represented by ecosystem models or empirically based estimates5,6. Here we synthesize regional in situ observations of CO2 flux