Study on the spatial dynamics and occurrence factors of Ulva spp.at the Yatsu Tidal Flat, Chiba Prefecture

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K01174
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Geography
• Research Institution: Rissho University
• Principal Investigator: SHIRAKI YOHEI 立正大学, 地球環境科学部, 准教授 (80508416)
• Co-Investigator(Kenkyū-buntansha): 千賀 有希子 東邦大学, 理学部, 准教授 (30434210) ; 北沢 俊幸 立正大学, 地球環境科学部, 専任講師 (40516861) ; 李 盛源 立正大学, 地球環境科学部, 特任講師 (90466665)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 地理情報システム / リモートセンシング / 地形 / 堆積物 / 潮流 / 栄養塩類（窒素・リン） / 窒素・炭素安定同位体 / 微生物活性

Outline of Final Research Achievements

This study focused on the spatial dynamics and occurrence factors of Ulva sp., and the following issues (1) to (3) were studied at the Yatsu Tidal Flat in Chiba prefecture. (1) Analysis of seasonal variation pattern in Ulva sp. (2) Influence of micro-landforms and hydraulic conditions on distribution of Ulva sp. (3)Specification of load source of nutrient salts needed for growth of Ulva sp. As the result, the following was clarified. (1)It was suggested the signal of seasonal change in Ulva sp. can be obtained using high spatial resolution satellite image data. (2) Southeastern inlet of the tidal flat is undulate and Ulva sp. is trapped on the bar at the late stage of ebb tide. (3) The presence of Ulva sp. affects the nutrients dynamics in Yatsu Tidal Flat. Especially, nitrogen uptake of Ulva sp. is greater with ammonium (NH4+) than with nitrate (NO3-). (4) It was suggested that nitrogen taken in from spring to autumn is returned to the tidal flat in the winter.

Free Research Field

環境動態学