B21G-0556
Seasonal and Inter-annual Changes in Photosynthetic and Soil Respiratory Processes in a Cool-temperate Deciduous Forest on a Mountainous Landscape in Japan.

Tuesday, 15 December 2015
Poster Hall (Moscone South)
Hiroyuki Muraoka1, Nam Jin Noh1, Taku M Saitoh1, Ayaka Nagao1, Hibiki M Noda2, Masatoshi Kuribayashi3 and Shin Nagai4, (1)Gifu University, Gifu, Japan, (2)NIES National Institute of Environmental Studies, Ibaraki, Japan, (3)Nagano Environmental Conservation Research Institute, Iizuka, Japan, (4)JAMSTEC Japan Agency for Marine-Earth Science and Technology, Department of Environmental Geochemical Cycle Research, Kanagawa, Japan
Abstract:
Carbon budget of terrestrial ecosystems is one of the most crucial themes in ecosystem sciences under current and future climate changes as it would affect our Earth system. Remote sensing and modeling analysis studies from continental to global scales have been indicating that the recent climate change is influential to photosynthetic processes in terrestrial vegetation such as forests and grasslands, by altering phenology (seasonal change) and foliage biomass. In addition, increasing temperature and possibly changing photosynthetic activities of plants are influential to soil carbon dynamics. Our deeper and broader understandings on such photosynthetic and respiratory processes governing carbon cycle and hence budget of terrestrial ecosystems are critical to detect the changes of ecosystem processes and the functions in changing environments, as they would influence the biodiversity, ecosystem services and Earth system.

In order to reveal the nature of temporal changes in photosynthetic and respiratory processes in forest ecosystems, we have been conducting multi-disciplinary observations of ecophysiological and optical properties for canopy photosynthesis in a cool-temperate deciduous forest since 2003 (“Takayama site”, contributing to AsiaFlux and JaLTER). In addition, open-field warming experiments have been conducted since 2011 to examine the possible influence of near-future warming condition on forest canopy photosynthesis and soil respiration. (1) Our long-term measurements of leaf and canopy photosynthesis revealed that their phenology is influenced by inter-annual variation of micrometeorological conditions. (2) Combined analysis of leaf-canopy photosynthesis and optical properties enabled us to estimate the forest photosynthetic productivity at regional scale by satellite data. (3) Open-field warming experiments suggested that tree foliage and soil processes would acclimate to near-future warming conditions.