Japan Geoscience Union Meeting 2018

Presentation information

[JJ] Oral

A (Atmospheric and Hydrospheric Sciences) » A-CG Complex & General

[A-CG43] Coastal Ecosystems - 2. Coral reefs, seagrass and macroalgal beds, and mangroves

Thu. May 24, 2018 1:45 PM - 3:15 PM 201B (2F International Conference Hall, Makuhari Messe)

convener:Toshihiro Miyajima(Marine Biogeochemistry Group, Division of Ocean-Earth System Science, Atmosphere and Ocean Research Institute, The University of Tokyo), Yu Umezawa(Tokyo University of Agriculture and Technology), Atsushi Watanabe(東京工業大学 環境・社会理工学院, 共同), Tomihiko Higuchi(Atmosphere and Ocean Research Institute, The University of Tokyo), Chairperson:Miyajima Toshihiro(The University of Tokyo), Umezawa Yu(Tokyo University of Agriculture and Technology)

2:30 PM - 2:45 PM

[ACG43-03] Coupled model system of vegetation model SEIB-DGVM and ocean model ROMS for modeling mangrove vegetation dynamics

*Takashi Nakamura1, Yoshikai Masaya1, Jun Yasuoka1, Sahadev Sharma2, Ryohei Egawa1, Naohiro Mori1, Takayuki Ideura1, Rempei Suwa3, Kazuo Nadaoka1 (1.Tokyo Institute of Technology, 2.University of Hawaii, 3.Forestry and Forest Products Research Institute)

Keywords:mangrove, vegetation dynamics, numerical simulation

Mangrove ecosystem has recently highlighted as an ecosystem which has higher capacity of organic carbon (blue carbon) storage. For predicting the change of the blue carbon stock responding to future environmental changes, elucidating and modeling mangrove vegetation dynamics is needed. Mangrove species composition and vegetation pattern are highly related to soil salinity and interspecies competition. In the Fukido mangrove area, Ishigaki Island, Japan, there are mainly two mangrove species Rhizophora stylosa, which is high salinity tolerance but low shade tolerance species, and Bruguiera gymnorhiza, which is low salinity tolerance but high shade tolerance species, and clear vegetation zonation is observed, i.e. R. stylosa is vegetated near the river mouth area and B. gymnorhiza is vegetated relatively far area from the river mouth.

For reproducing such mangrove vegetation pattern, fine-scale mapping of soil salinity is one of very important components, because zonation pattern should be closely linked with soil salinity pattern. However, it is difficult to obtain the fine-scale mapping only by field observation. Therefore, firstly to obtain fine-scale soil salinity map in the Fukido mangrove area, 3D hydrodynamic model for Fukido mangrove area is developed based on the Regional Ocean Modeling System (ROMS; Shchepetkin and McWilliams 2005; Haidvogel et al. 2008).

Mangrove vegetation pattern is, of course, not only caused by soil salinity pattern but also by other factors such as light competition between the mangrove species. Spatially Explicit Individual Based Dynamic Global Vegetation Model (SEIB-DGVM; Sato et al. 2007) is a dynamic vegetation model and is incorporated plant light competition process. The SEIB-DGVM is powerful tool for computing dynamic plant vegetation, but it cannot be cared spatial heterogeneity inside the computational domain. Therefore the SEIB-DGVM was largely modified to be able to import spatially varied soil salinity calculated by ROMS. In addition, biological features of two mangrove species, i.e. salinity tolerance and shade tolerance, were incorporated in the SEIB-DGVM.
This coupled model system of SEIB-DGVM and ROMS was performed for reproducing vegetation pattern of two mangrove species, R. stylosa and B. gymnorhiza, in Fukido mangrove area. In the result of the simulation, although further improvement and validation are needed, trend of the vegetation patterns of two mangrove species was well reproduced.