Experimental observations of water stress effects on the phenology of a tropical deciduous forest and the impact on the vegetation model

2014 Fiscal Year Final Research Report

• Project/Area Number: 24310018
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Environmental dynamic analysis
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: TANAKA KATSUNORI 独立行政法人海洋研究開発機構, 地球表層物質循環研究分野, 主任研究員 (80344274)
• Co-Investigator(Kenkyū-buntansha): SUZUKI Masakazu 東京大学, 農学生命科学研究科, 教授 (10144346) ; TANAKA Nobuaki 東京大学, 農学生命科学研究科, 助教 (10323479) ; MATSUO Naoko 三重大学, 生物資源学研究科, 講師 (00423012)
• Co-Investigator(Renkei-kenkyūsha): KOSUGI Yoshiko 京都大学, 農学研究科, 助教 (90293919)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: フェノロジー / 落葉チーク / 土壌水分 / 幹成長 / 光合成能

Outline of Final Research Achievements

Observations of a teak plantation revealed that under natural conditions the trees significantly decreased sap flow and lost their leaves in the dry season between February and April 2014. In comparison, under controlled well-watered soil conditions, the subject teak trees did not open new leaves and ceased sap flow until March 2014. Two weeks later, the watered trees opened new leaves, and the sap flow once again increased. The stem growth of all the trees increased from April to September 2014 under both natural and well-watered conditions. Additionally, leaf nitrogen content, corresponding to the photosynthesis capacity decreased with lower soil moisture. Leaf nitrogen content capacity decreased more slowly in the watered trees. Lower carbon gain per water use was also observed in the trees subject to controlled watering conditions. Therefore, we believe the amount of soil moisture in the root zone directly influences sap flow, new leaves, and leaf fall.

Free Research Field

植生水文学