RESEARCH
Terrestrial ecosystem dynamics modeling
The threat of climate change to tropical rainforests becomes a hot topic in recent years. The major threat comes from drought. Recently it is pointed out that droughts consistently had a more detrimental impacts on larger trees in forests worldwide. In order to assess the risk of size-dependent mortality of trees in a tropical rainforest, the “way of life” of each tree should be described and taken into account individually, which is the motivation that Dr. Kumagai and I are developing a new terrestrial ecosystem dynamics model (based on the SEIB-DGVM developed by Dr. Sato).
Soil moisture dynamics and ecohydrology
Root zone soil moisture is a key ecohydrological state variable, with its temporal variability and associated ”memory” or ”persistency” strongly tied to biogeochemical cycling, plant-water relations, and other ecohydrological processes at various scales. Temporal variability in soil moisture is basically controlled by rainfall and radiation (through evapotranpiration), and thus the future climate change can affect such dynamics significantly. I'm interested in the interrelationship between soil moisture dynamics and plant physiology, especially in the high latitude permafrost region under future climate change.
Eddy covariance flux measurements
Eddy covariance technique is a well-developed method for measuring heat, water, and CO2 fluxes between terrestrial ecosystem and the atmosphere. This method is based on the premise that the sonic anemometer and infrared gas analyzer measure the meteorological variables correctly. However, such instruments can have sensor-specific errors and/or characteristic traits. My challenges have focused on how these uncertainties in flux measurements can be reduced.
Vegetation-atmosphere interaction
Scalar exchange between vegetation and the atmosphere is driven by the turbulent wind field, and the wind flow characteristics are affected by the structure of vegetation canopy. Such characteristics are important for understanding both local micrometeorological phenomena and global biogeochemical cycling, and thus the flow dynamics within and above the vegetation canopy has been the core interest of my research.