Trees

, Volume 21, Issue 4, pp 479–490

Temporal variation of δ13C of larch leaves from a montane boreal forest in Mongolia

Authors

    • Synthesis Research CenterInstitute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences
    • Japan Science and Technology Agency
  • Maki Tsujimura
    • Division of Geo-Environmental SciencesGraduate School of Life and Environmental Sciences, University of Tsukuba
  • Atsuko Sugimoto
    • Division of GeosciencesGraduate School of Environmental Earth Science, Hokkaido University
  • Gombo Davaa
    • Institute of Meteorology and Hydrology
  • Dambaravjaa Oyunbaatar
    • Institute of Meteorology and Hydrology
  • Michiaki Sugita
    • Division of Geo-Environmental SciencesGraduate School of Life and Environmental Sciences, University of Tsukuba
Original Paper

DOI: 10.1007/s00468-007-0142-2

Cite this article as:
Li, S., Tsujimura, M., Sugimoto, A. et al. Trees (2007) 21: 479. doi:10.1007/s00468-007-0142-2

Abstract

This paper reports the temporal variation (2002–2004) in foliar δ13C values, which are indicative of long-term integrated photosynthetic and water use characteristics, of Siberian larch (Larix sibirica Ledeb.) trees in a montane forest at Mongonmorit, NE Mongolia. At the stand, the δ13C value for understory shaded leaves was more negative by 2‰ on average than that for sunlit leaves sampled concurrently from open and sun-exposed environments in a forest gap. The δ13C value of both sunlit and shaded leaves showed pronounced intra- but relatively small inter-seasonal variations. The δ13C value was more positive for juvenile than mature leaves. We conjecture that juvenile leaves may derive carbon reserves in woody tissues (e.g., stems). Regardless of leaf habitats, the δ13C value was also affected by insect herbivores occurred in mid summer of 2003, being more negative in newly emerging leaves from the twigs after defoliation than in non-defoliated mature leaves. This pattern seems to contrast with that for the juvenile leaves in the early growing season. We surmise that the newly emerging leaves used stored organic carbon that was depleted due to fractionation during remobilization and translocation for leaf regrowth. There was also intra- and inter-seasonal variation in the foliar N concentrations and C:N ratios. A good positive (negative) correlation between the foliar δ13C values and N concentrations (C:N ratios) was also observed for both sunlit and shaded leaves, suggesting that the relationship between water and nitrogen use is a crucial factor affecting the plant carbon–water relationship in this mid latitude forest with a cold semiarid climate. Our isotopic data demonstrate that the larches in NE Mongolia exhibits relatively higher water use efficiency with a distinct within-season variability.

Keywords

Larix sibiricaδ13CFoliar nitrogenWater use efficiencyInsect herbivoreCold semiarid ecosystem

Copyright information

© Springer-Verlag 2007