Estimation of the depth of water uptake by tropical trees; the mechanisms for the flowering frequency and timing in general flowering

2015 Fiscal Year Final Research Report

• Project/Area Number: 26660124
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Forest science
• Research Institution: Nagoya University
• Principal Investigator: NAKAGAWA Michiko 名古屋大学, 生命農学研究科, 准教授 (70447837)
• Co-Investigator(Kenkyū-buntansha): MATSUO Naoko 三重大学, 大学院生物資源学研究科, 講師 (00423012)
• Research Collaborator: KAWAHARA Kazuma
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 開花頻度 / 吸水深度 / 東南アジア熱帯雨林

Outline of Final Research Achievements

We hypothesized that the interspecific differences in water uptake depth may influence the flowering frequency and timing in general flowering (GF) among tree species in lowland tropical rain forests in Southeast Asia. The flowering frequency differed significantly among species and the flowering peak of high-frequency flowering species preceded that of low-frequency species. The soil water sources of the dipterocarp trees were assessed using oxygen stable isotope composition (δ18O) with snap-shot and sequence-sampling methods. Although both an unclear vertical profile of soil water δ18O and the short sampling term made it difficult to determine the water uptake depth using either method, δ18O of shallower soil and high-frequency flowering dipterocarp trees seems to fluctuate more largely. However, an accurate estimation of vertical pattern of soil water use using long-term sequence-sampling method is required to fully test our hypothesis.

Free Research Field

森林生態学