<h2>Feedbacks of Arctic Ecosystems to the Climate System Vegetation Responses
      of Energy and Greenhouse Gas Exchange to the Climate Change</h2>
  <p><strong>Researchers:</strong>Yoshinobu Harazono and Hiroki Iwata<br />
        <strong>Funding Source: </strong>IARC/NSF<br />
        <strong>Collaborators:</strong> Masahito Ueyama (Osaka Prefecture Univ.), Toru Iwata (Okayama
        Univ.), Akira Miyata (National Institute for Agro-Environmental Sciences), Walter C. Oechel (San
        Diego State Univ.), Kazuhito Ichii (Fukushima Univ.), John Kimball (Univ. of Montana)</p>
      <p > The project goals are 1) To improve our understanding of the effects of changing permafrost
        on the regional hydrology and greenhouse gas budget, by continuous energy and trace gas flux
        observations at arctic and subarctic ecosystems. 2) To reveal the key parameters controlling
        carbon and energy budget of arctic and subarctic ecosystems, by comparing observed data and tuned
        process-based models such as BIOME-BGC, resulting in the future contributions of larger-scale
        climate estimation.</p>
      <p > We continue the long-term flux observations of energy, CO<sub>2</sub>, and water vapor by
        the eddy correlation method and methane by the gradient method throughout the year in a black
        spruce forest in interior Alaska. The compiled data are applied to examine the key parameters
        controlling the energy and carbon exchange in the ecosystem. The ecosystem process model is improved
        by applying the observation data. Also, the data are provided for scientific purposes and are
        shared among ecosystem model study groups. </p>
      <p > A unique observation site, which is the only tower site operated throughout the year in the
        high-latitude boreal ecosystem, is kept by IARC to reduce uncertainties in hydrology and carbon
        cycle in the high-latitude ecosystem. The observed data are complied and shared among model study
        groups. The compiled data and examined key parameters are applied to improve the tuned process-based
        ecosystem model, and the future changes in hydrology and carbon cycle are estimated.</p>
      <p > The observed data are unique to high-latitude ecosystems. The data are complied and shared
        among model study groups. Also the key parameters are synthesized with the process-based model,
        resulting in better estimations of future hydrology and carbon cycles in high-latitude ecosystems.</p>