Charles D Koven

Dados Biográficos

ID6819624
NOMECharles D Koven
PRENOMESCharles D
SOBRENOMEKoven
ASSINATURAKOVEN C D
AFILIAÇÕESLawrence Berkeley National Laboratory
ORCID0000-0002-3367-0065
VERIFICADOSim
TOTAL DE OBRAS14
TOTAL DE CITAÇÕES0
TOTAL COMO AUTOR14
TOTAL COMO EDITOR0
PRIMEIRO ANO DE PUBLICAÇÃO2014
ANO MAIS RECENTE DE PUBLICAÇÃO2023
ÍNDICE H0

  • The drivers and impacts of Amazon forest degradation

    Open AccessDavid M Lapola, Patricia Pinho et al.ARTICLEScience2023

    Approximately 2.5 × 10 6 square kilometers of the Amazon forest are currently degraded by fire, edge effects, timber extraction, and/or extreme drought, representing 38% of all remaining forests in the region. Carbon emissions from this degradation total up to 0.2 petagrams of carbon per year (Pg C year −1 ), which is equivalent to, if not greater than, the emissions from Amazon deforestation (0.06 to 0.21 Pg C year −1 ). Amazon forest degradatio…

  • Soil moisture thresholds explain a shift from light-limited to water-limited sap velocity in the Central Amazon during the 2015–16 El Niño drought

    Open AccessLin Meng, Jeffrey Q Chambers et al.ARTICLEEnvironmental Research Letters2022

    Transpiration is often considered to be light- but not water-limited in humid tropical rainforests due to abundant soil water, even during the dry seasons. The record-breaking 2015–16 El Niño drought provided a unique opportunity to examine whether transpiration is constrained by water under severe lack of rainfall. We measured sap velocity, soil water content, and meteorological variables in an old-growth upland forest in the Central Amazon thro…

  • Much of zero emissions commitment occurs before reaching net zero emissions

    Open AccessCharles D Koven, Benjamin M Sanderson et al.ARTICLEEnvironmental Research Letters2022

    We explore the response of the Earth’s coupled climate and carbon system to an idealized sequential addition and removal of CO 2 to the atmosphere, following a symmetric and continuous emissions pathway, in contrast to the discontinuous emissions pathways that have largely informed our understanding of the climate response to net zero and net negative emissions to date. We find, using both an Earth system model and an ensemble of simple climate m…

  • Uncertainty in land carbon budget simulated by terrestrial biosphere models

    Open AccessLucas Hardouin, Christine Delire et al.ARTICLEEnvironmental Research Letters2022

    Global estimates of the land carbon sink are often based on simulations by terrestrial biosphere models (TBMs). The use of a large number of models that differ in their underlying hypotheses, structure and parameters is one way to assess the uncertainty in the historical land carbon sink. Here we show that the atmospheric forcing datasets used to drive these TBMs represent a significant source of uncertainty that is currently not systematically a…

  • Recent California tree mortality portends future increase in drought-driven forest die-off

    Open AccessGavin D Madakumbura, Michael L Goulden et al.ARTICLEEnvironmental Research Letters2020

    Vegetation tolerance to drought depends on an array of site-specific environmental and plant physiological factors. This tolerance is poorly understood for many forest types despite its importance for predicting and managing vegetation stress. We analyzed the relationships between precipitation variability and forest die-off in California’s Sierra Nevada and introduce a new measure of drought tolerance that emphasizes plant access to subsurface m…

  • Non-uniform seasonal warming regulates vegetation greening and atmospheric CO 2 amplification over northern lands

    Open AccessZhao Li, Jianyang Xia et al.ARTICLEEnvironmental Research Letters2018

    The enhanced vegetation growth by climate warming plays a pivotal role in amplifying the seasonal cycle of atmospheric CO 2 at northern lands (>50N) since 1960s. However, the correlation between vegetation growth, temperature and seasonal amplitude of atmospheric CO 2 concentration have become elusive with the slowed increasing trend of vegetation growth and weakened temperature control on CO 2 uptake since late 1990s. Here, based on in situ atmo…

  • Divergent patterns of experimental and model-derived permafrost ecosystem carbon dynamics in response to Arctic warming

    Open AccessChristina Schädel, Charles D Koven et al.ARTICLEEnvironmental Research Letters2018

    In the last few decades, temperatures in the Arctic have increased twice as much as the rest of the globe. As permafrost thaws in response to this warming, large amounts of soil organic matter may become vulnerable to decomposition. Microbial decomposition will release carbon (C) from permafrost soils, however, warmer conditions could also lead to enhanced plant growth and C uptake. Field and modeling studies show high uncertainty in soil and pla…

  • Vulnerability of Amazon forests to storm-driven tree mortality

    Open AccessRobinson Negrón‐Juárez, Jennifer A Holm et al.ARTICLEEnvironmental Research Letters2018

    Tree mortality is a key driver of forest community composition and carbon dynamics. Strong winds associated with severe convective storms are dominant natural drivers of tree mortality in the Amazon. Why forests vary with respect to their vulnerability to wind events and how the predicted increase in storm events might affect forest ecosystems within the Amazon are not well understood. We found that windthrows are common in the Amazon region exte…

  • Global wetland contribution to 2000–2012 atmospheric methane growth rate dynamics

    Open AccessBenjamin Poulter, Philippe Bousquet et al.ARTICLEEnvironmental Research Letters2017

    Increasing atmospheric methane (CH 4 ) concentrations have contributed to approximately 20% of anthropogenic climate change. Despite the importance of CH 4 as a greenhouse gas, its atmospheric growth rate and dynamics over the past two decades, which include a stabilization period (1999–2006), followed by renewed growth starting in 2007, remain poorly understood. We provide an updated estimate of CH 4 emissions from wetlands, the largest natural …

  • Regional carbon fluxes from land use and land cover change in Asia, 1980–2009

    Open AccessLeonardo Calle, Josep G Canadell et al.ARTICLEEnvironmental Research Letters2016

    We present a synthesis of the land-atmosphere carbon flux from land use and land cover change (LULCC) in Asia using multiple data sources and paying particular attention to deforestation and forest regrowth fluxes. The data sources are quasi-independent and include the U.N. Food and Agriculture Organization-Forest Resource Assessment (FAO-FRA 2015; country-level inventory estimates), the Emission Database for Global Atmospheric Research (EDGARv4.…

  • The terrestrial carbon budget of South and Southeast Asia

    Open AccessMatthew Cervarich, Shijie Shu et al.ARTICLEEnvironmental Research Letters2016

    Accomplishing the objective of the current climate policies will require establishing carbon budget and flux estimates in each region and county of the globe by comparing and reconciling multiple estimates including the observations and the results of top-down atmospheric carbon dioxide (CO 2 ) inversions and bottom-up dynamic global vegetation models. With this in view, this study synthesizes the carbon source/sink due to net ecosystem productiv…

  • Permafrost thaw and resulting soil moisture changes regulate projected high-latitude CO 2 and CH 4 emissions

    Open AccessDavid M Lawrence, Charles D Koven et al.ARTICLEEnvironmental Research Letters2015

    The fate of currently frozen permafrost carbon as high-latitude climate warms remains highly uncertain and existing models give widely varying estimates of the permafrost carbon-climate feedback. This uncertainty is due to many factors, including the role that permafrost thaw-induced transitions in soil hydrologic conditions will have on organic matter decomposition rates and the proportion of aerobic to anaerobic respiration. Large-scale permafr…

  • Observed allocations of productivity and biomass, and turnover times in tropical forests are not accurately represented in CMIP5 Earth system models

    Open AccessRobinson Negrón‐Juárez, Robinson I Negrón-Juárez et al.ARTICLEEnvironmental Research Letters2015

    A significant fraction of anthropogenic CO2 emissions is assimilated by tropical forests and stored as biomass, slowing the accumulation of CO2 in the atmosphere. Because different plant tissues have different functional roles and turnover times, predictions of carbon balance of tropical forests depend on how earth system models (ESMs) represent the dynamic allocation of productivity to different tree compartments. This study shows that observed …

  • Estimated stocks of circumpolar permafrost carbon with quantified uncertainty ranges and identified data gaps

    Open AccessGustaf Hugelius, Jens Strauss et al.ARTICLEBiogeosciences2014

    Soils and other unconsolidated deposits in the northern circumpolar permafrost region store large amounts of soil organic carbon (SOC). This SOC is potentially vulnerable to remobilization following soil warming and permafrost thaw, but SOC stock estimates were poorly constrained and quantitative error estimates were lacking. This study presents revised estimates of permafrost SOC stocks, including quantitative uncertainty estimates, in the 0–3 m…