Lukas Kohl

Lukas Kohl
University of Helsinki | HY · Insitute of Atmosphere and Earth System Research (INAR)

PhD

About

31
Publications
4,691
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236
Citations
Introduction
At the intersection of microbiology, organic geochemistry, and biogeochemistry, I am interested in human impact on natural biogeochemical cycles. I currently study the methane cycle of boreal forests with a focus on the role of trees. In the past, I used chemical and isotopic methods to investigating litter decomposition, soil organic matter cycling, methanogenesis in extreme habitats, petroleum derived contaminants, and the toxic legacy of wildfires in house dust.
Additional affiliations
October 2018 - present
University of Helsinki
Position
  • PostDoc Position
March 2017 - September 2018
University of Toronto
Position
  • PostDoc Position
May 2012 - February 2017
Memorial University of Newfoundland
Position
  • PhD Student

Publications

Publications (31)
Article
Full-text available
Volatile organic compounds (VOCs) play an essential role in climate change and air pollution by modulating tropospheric oxidation capacity and providing precursors for ozone and aerosol formation. Arctic permafrost buries large quantities of frozen soil carbon, which could be released as VOCs with permafrost thawing or collapsing as a consequence o...
Article
Plant litter chemistry is altered during decomposition but it remains unknown if these alterations, and thus the composition of residual litter, will change in response to climate. Selective microbial mineralization of litter components and the accumulation of microbial necromass can drive litter compositional change, but the extent to which these...
Article
Full-text available
Plant shoots can act as sources or sinks of trace gases including methane and nitrous oxide. Accurate measurements of these trace gas fluxes require enclosing of shoots in closed non-steady-state chambers. Due to plant physiological activity, this type of enclosure, however, leads to CO2 depletion in the enclosed air volume, condensation of transpi...
Article
House dust is an important medium for exposure to persistent pollutants, such as metals. Detailed characterization of metal composition is needed to identify sources and potential health impacts of exposure. In this study we show that specific metals in dust dominate in different locations within residential homes in a mid-size Canadian city (Fort...
Article
Full-text available
Authorship conflicts are a common occurrence in academic publishing, and they can have serious implications for the careers and well-being of the involved researchers as well as the collective success of research organizations. In addition to not inviting relevant contributors to co-author a paper, the order of authors as well as honorary , gift, a...
Article
Full-text available
Peatlands are important natural sources of atmospheric methane (CH 4) emissions. The production and emission of CH 4 are strongly influenced by the diffusion of oxygen into the soil and of CH 4 from the soil to the atmosphere , respectively. This diffusion, in turn, is controlled by the structure of macropore networks. The characterization of peat...
Article
Full-text available
‐Plants are recognized as sources of aerobically produced methane (CH4), but the seasonality, environmental drivers and significance of CH4 emissions from the canopies of evergreen boreal trees remain poorly understood. ‐We measured the CH4 fluxes from the shoots of Pinus sylvestris (Scots pine) and Picea abies. (Norway spruce) saplings in a static...
Preprint
Peatlands are important natural sources of atmospheric methane (CH4) emissions. The emissions are strongly influenced by the diffusion of oxygen into the soil and of CH4 from the soil to the atmosphere. This diffusion, in turn, is controlled by the structure of macropore networks. The characterization of peat pore structure and connectivity through...
Preprint
Full-text available
Authorship conflicts are a common occurrence in academic publishing, and they can have serious implications on the careers and well-being of the involved researchers, as well as the collective success of research organizations. In addition to not inviting relevant contributors to co-author a manuscript, the order of authors, as well as honorary, gi...
Preprint
Full-text available
Plant shoots can act as sources or sinks of trace gases including methane and nitrous oxide. Accurate measurementsof these trace gas fluxes require enclosing of shoots in closed non-steady state chambers. Due to plant physiological activity, this type of enclosures, however, lead to CO2 depletion in the enclosed air volume, condensation of transpir...
Article
Full-text available
Studies that quantify plant methane CH4 emission rely on the accurate measurement of small changes in the mixing ratio of CH_4 that coincide with much larger changes in the mixing ratio of volatile organic compounds (VOCs). Here, we assessed if 11 commonly occurring VOCs (e.g., methanol, alpha- and beta-pinene, Delta3-carene) interfered with the qu...
Preprint
Full-text available
Studies that quantify plant methane (CH4) emission rely on the accurate measurement of small changes CH4 concentrations that coincide with much larger changes in the concentration of volatile organic compounds (VOCs). Here, we assessed if 11 commonly occurring VOCs (e.g., methanol, α- and β-pinene, ∆3-carene) interfered with CH4 concentrations meas...
Article
Full-text available
Plain Language Summary Wildfires release large amounts of toxic pollutants like heavy metals and polycyclic aromatic hydrocarbons. So far, it remains unknown if and how long these pollutants stay in local houses after a fire. We collected house dust samples from 64 houses in Fort McMurray (Alberta, Canada), where a wildfire forced the evacuation of...
Chapter
Since 2012, the scallop fishery in Port au Port Bay, Newfoundland, Canada has experienced a drastic decline, while no decline was observed in adjacent St. George's Bay. Local fishermen have raised concerns about an abandoned oil exploration well in the Port au Port Bay. This study investigated the potential impact of petroleum hydrocarbons on sedim...
Article
Full-text available
Warmer climates have been associated with reduced bioreactivity of soil organic matter (SOM) typically attributed to increased diagenesis; the combined biological and physiochemical transformation of SOM. Additionally, cross site studies have indicated that ecosystem regime shifts, associated with long-term climate warming, can affect SOM propertie...
Article
Second Deep Carbon Observatory Summer School; Yellowstone National Park, Montana and Wyoming, 23–28 July 2016
Conference Paper
In 2013 the scallop fishery in Port au Port Bay, Newfoundland began to drastically decline. The cause of this decline is still unknown; however, several abandoned oil exploration wells that were leaking an oily substance have been identified around the bay. This project investigated whether the decline of the scallop fishery could be related to con...
Article
Present-day serpentinization generates groundwaters with conditions (pH > 11, Eh < -550mV) favorable for the microbial and abiotic production of organic compounds from inorganic precursors. Elevated concentrations of methane, C2-C6 alkanes, acetate, and formate were detected at these sites, but the microbial or abiotic origin of these compounds rem...
Article
Full-text available
Soil microbial biomass is a key source of soil organic carbon (SOC), and the increasing proportion of microbially derived SOC is thought to drive the enrichment of 13 C during SOC decomposition. Yet, little is known about how the d 13 C of soil microbial biomass differs across space or time, or with the composition of the microbial community. Varia...
Article
Full-text available
Ultra-basic reducing springs at continental sites of serpentinization act as portals into the biogeochemistry of a subsurface environment with H2 and CH4 present. Very little, however, is known about the carbon substrate utilization, energy sources, and metabolic pathways of the microorganisms that live in this ultra-basic environment. The potentia...
Article
Full-text available
Glucans like cellulose and starch are a major source of carbon for decomposer food webs, especially during early- and intermediate-stages of decomposition. Litter quality has previously been suggested to notably influence decomposition processes as it determines the decomposability of organic material and the nutrient availability to the decomposer...
Article
Full-text available
Fluvial ecosystems process large quantities of dissolved organic matter as it moves from the headwater streams to the sea. In particular, hyporheic sediments are centers of high biogeochemical reactivity due to their elevated residence time and high microbial biomass and activity. However, the interaction between organic matter and microbial dynami...

Projects

Projects (3)
Project
We characterize house dust pollutant concentrations in Fort McMurray after a major wildfire in 2016.