Joshua C Koch

Biographic Data

ID7993871
NAMEJoshua C Koch
GIVEN NAMESJoshua C
FAMILY NAMEKoch
SIGNATUREKOCH J C
AFFILIATIONSUnited States Geological Survey
ORCID0000-0001-7180-6982
VERIFIEDYes
TOTAL WORKS5
TOTAL CITATIONS0
AUTHOR COUNT5
EDITOR COUNT0
FIRST PUBLICATION YEAR2013
LATEST PUBLICATION YEAR2023
H-INDEX0

  • Increasing Alaskan river discharge during the cold season is driven by recent warming

    Open AccessDylan Blaskey, Joshua C Koch et al.ARTICLEEnvironmental Research Letters2023

    Arctic hydrology is experiencing rapid changes including earlier snow melt, permafrost degradation, increasing active layer depth, and reduced river ice, all of which are expected to lead to changes in stream flow regimes. Recently, long-term (>60 years) climate reanalysis and river discharge observation data have become available. We utilized these data to assess long-term changes in discharge and their hydroclimatic drivers. River discharge dur…

  • Sensitivity of headwater streamflow to thawing permafrost and vegetation change in a warming Arctic

    Open AccessJoshua C Koch, Ylva Sjöberg et al.ARTICLEEnvironmental Research Letters2022

    Climate change has the potential to impact headwater streams in the Arctic by thawing permafrost and subsequently altering hydrologic regimes and vegetation distribution, physiognomy and productivity. Permafrost thaw and increased subsurface flow have been inferred from the chemistry of large rivers, but there is limited empirical evidence of the impacts to headwater streams. Here we demonstrate how changing vegetation cover and soil thaw may alt…

  • Dissolved organic carbon and nitrogen release from boreal Holocene permafrost and seasonally frozen soils of Alaska

    Open AccessKimberly P Wickland, Mark P Waldrop et al.ARTICLEEnvironmental Research Letters2018

    Permafrost (perennially frozen) soils store vast amounts of organic carbon (C) and nitrogen (N) that are vulnerable to mobilization as dissolved organic carbon (DOC) and dissolved organic and inorganic nitrogen (DON, DIN) upon thaw. Such releases will affect the biogeochemistry of permafrost regions, yet little is known about the chemical composition and source variability of active-layer (seasonally frozen) and permafrost soil DOC, DON and DIN. …

  • Effect of permafrost thaw on CO 2 and CH 4 exchange in a western Alaska peatland chronosequence

    Open AccessCarmel E Johnston, S A Ewing et al.ARTICLEEnvironmental Research Letters2014

    Permafrost soils store over half of global soil carbon (C), and northern frozen peatlands store about 10% of global permafrost C. With thaw, inundation of high latitude lowland peatlands typically increases the surface-atmosphere flux of methane (CH _4 ), a potent greenhouse gas. To examine the effects of lowland permafrost thaw over millennial timescales, we measured carbon dioxide (CO _2 ) and CH _4 exchange along sites that constitute a ∼1000 …

  • Reorganization of vegetation, hydrology and soil carbon after permafrost degradation across heterogeneous boreal landscapes

    Open AccessM Torre Jorgenson, J W Harden et al.ARTICLEEnvironmental Research Letters2013

    The diversity of ecosystems across boreal landscapes, successional changes after disturbance and complicated permafrost histories, present enormous challenges for assessing how vegetation, water and soil carbon may respond to climate change in boreal regions. To address this complexity, we used a chronosequence approach to assess changes in vegetation composition, water storage and soil organic carbon (SOC) stocks along successional gradients wit…