20.500.12556/RUL-69767 Age dependence of xylogenesis and its climatic sensitivity in Smith fir on the south-eastern Tibetan Plateau An age effect on growth trends and climate/growth relationships of trees can possibly be discovered by analysing the seasonal dynamics of xylem development. The aims of this study, therefore, were to compare xylem formation of young (43 ± 4 years) and old (162 ± 26 years) Smith fir (Abies georgei var. smithii (Viguie & Gaussen) W. C. Cheng & L. K. Fu) trees in the Sygera Mountains, south-eastern Tibetan Plateau and, to identify the association between wood formation and climate. The seasonal radial growth dynamics of young and old trees was monitored on microcores collected at weekly intervals during two growing seasons. Transverse sections through phloem, cambium and outermost xylem of 9–12 µm thickness were observed with a light microscope under bright field and polarized light to follow the cambial activity and differentiation of the developing xylem. Young trees were characterized by an earlier onset of xylogenesis, a longer growing season and a higher growth rate, resulting in a higher number of xylem cells. Both young and old trees responded fast to changes of the minimum air temperature, confirming that this factor was dominant by controlling Smith fir growth on the south-eastern Tibetan Plateau. dendroklimatologija rast lesa Abies georgei var. smithii true false false Angleški jezik Neznan jezik Znanstveno delo 2015-07-10 21:35:32 2015-07-10 21:35:32 2022-07-12 03:53:16 0000-00-00 00:00:00 2013 0 0 Str. 48-56 št. 1 Vol. 33 2013 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 630*561.24:630*630*111.8 0829-318X 2076553 http://treephys.oxfordjournals.org/content/early/2012/11/25/treephys.tps113.full.pdf+html 1 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=69778 Biotehniška fakulteta 0 0 0