4:45 PM - 5:00 PM
[BBG01-05] Spatial and vertical variations of carbon and nitrogen isotopes of larch forest and NDVI in Eastern Siberia
Keywords:taiga (boreal) forest, NDVI, carbon isotope, nitrogen isotope
Observations were conducted at Spasskaya Pad forest station (62°25’ N, 129°62’ E) near Yakutsk, Russia. The forest is usually dry, but after the extreme wet event in 2007, wet sites were distributed in the forest. Transect (60m x 510m) with 30m x 30m plots, in total 33, was set including dry sites and wet sites, to obtain needle samples from 104 trees at the height of 5-6 m were obtained in order to investigate spatial variations in δ13C, δ15N, and N contents. These spatial variations were compared with satellite-derived Normalized difference vegetation index (NDVI) using Landsat images with the resolution of 30 m. Lower NDVI and lower foliar N content were observed at wet sites than those at dry sites. A high δ13C and high δ15N were also observed at a wet site. After extreme wet event happened, ecosystem (and N availability) changes and NDVI also changes. We also obtained the needles from two trees at different heights in a jungle gym to investigate the vertical variations in δ13C and δ15N. There were large differences in δ13C, δ15N and N contents vertically.
Tei, S., A. Sugimoto, H. Yonenobu, T. Ohta, T. C. Maximov. Growth and physiological responses of larch trees to climate changes deduced from tree-ring widths and δ13C at two forest sites in eastern Siberia. Polar Science, 8, 183-195, doi:10.1016/j.polar.2013.12.002, 2014
Popova A.S., N. Tokuchi, N. Ohte, M.U. Ueda, K. Osaka, T.Ch. Maximov and A. Sugimoto. Nitrogen availability in the taiga forest ecosystem of northeastern Siberia. Soil Science and Plant Nutrition, 59, 427-441, doi:10.1080/00380768.2013.772495, 2013