| Intera-annual variations of δ13 C isotopes in tree rings of Oriental Beech (Fagus orientalis) in the central Caspian Forests of Iran |
| Paper ID : 1014-ADA2013 |
| Authors: |
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Negar Rezaei *1, Kambiz Pourtahmasi2, Achim Bräuning3 1khayam Alley,35 metri golestan Ave, Janatabad,Tehran,Iran 2P.O.Box 31585-1356 3Kochstrasse 4/4, D-91354 Erlangen |
| Abstract: |
| The Hyrcanian Forests are the major source of wood production and tree species biodiversityin Iran. Covering a vast area of these forests (32.7%), Oriental beech (Fagus orientalis Lipsky) is one of the dominant tree species at altitudes ranging from 700-2000 meters,intermixed with other broad-leaved species like Caucasian oak (Quercus castaneifolia). Tree growth is influenced by environmental and climate changes that have effects on several parameters in growth rings. So far, information on the growth behavior of trees is especially lacking in higher elevations which are expected to be strongly affected by climate change. By studying the variations of stable carbon and oxygen isotopes within a tree ring,information about the influence of seasonal climatic factors on tree ecology can be obtained which is differing from other tree-ring parameters.However, stable isotope ratios vary in different ways in different species, years, and at different sites. The present study aims at providing an appropriate understanding of the climate signals influencing stable carbon and oxygen isotopes in tree rings of various broad-leaved tree species growing in mountain forests. To investigate the stable isotope variations in the growth rings of beech, we extracted 10 increment core samples from 5 living trees at 1700 m elevation, close to the upper limit of beech. After cross-dating the growth rings with the help of anexisting reference chronology, we prepared intra-annual stable isotope samples with a resolution of 30 m using a rotary microtome.Intra-annual isotope ratios were measured with an Isotope Ratio Mass Spectrometer (IRMS) and correlated with climate data obtained from aweather station installed near the study site. The relationships between seasonal isotope ratio changes and climatic factors are presented in detail and the dominant environmental factors influencing seasonal patterns of stable isotope variations in beech are discussed. |
| Keywords: |
| Hyrcanian forests; climate change; seasonal climatic factors; Oriental beech; Tree rings |
| Status : Abstract Accepted |
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