Tree ring width, oxygen, carbon and nitrogen isotope analyses for ecosystem change

2017 Fiscal Year Final Research Report

• Project/Area Number: 26281003
• 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: Hokkaido University
• Principal Investigator: Sugimoto Atsuko 北海道大学, 北極域研究センター, 教授 (50235892)
• Co-Investigator(Kenkyū-buntansha): 米延 仁志 鳴門教育大学, 大学院学校教育研究科, 教授 (20274277) ; Lopez Larry 山形大学, 農学部, 准教授 (20374712) ; 山下 洋平 北海道大学, 地球環境科学研究院, 准教授 (50432224) ; 星野 仏方 酪農学園大学, 農食環境学群, 教授 (80438366)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: モンゴル / 年輪同位体 / タイガ林 / 土壌水分 / 窒素循環

Outline of Final Research Achievements

Analyses lines were developed for tree ring oxygen and nitrogen isotopes. Carbon, oxygen and nitrogen isotopes were analyzed for tree ring samples obtained from taiga at north Mongolia. Carbon and oxygen isotopes showed similar trend, with higher values under dryer conditions. Higher nitrogen was observed for tree ring at grassland boundary than that at forest site. Nitrogen isotope was also observed for 5-year period, and no clear correlations with temperature and precipitation fluctuations were observed. These tree ring nitrogen isotopes at forest site and grassland boundary showed different trends, and suggested nitrogen dynamics at each ecosystem. Growth of larch trees at grassland boundary seem to be limited due to a dry condition, however sufficient right and nitrogen conditions may contribute the growth of trees.

Free Research Field

生物地球科学