Natural decomposition of hornbeam wood decayed by the white rot fungus Trametes versicolor

ABSTRACT The impacts of white-rot fungi on altering wood chemistry have been studied mostly in vitro. However, in vivo approaches may enable better assessment of the nature of interactions between saprotrophic fungi and host tree in nature. Hence, decayed and sound wood samples were collected from a naturally infected tree (Carpinus betulus L.). Fruiting bodies of the white rot fungus Trametes versicolor grown on the same tree were identified using rDNA ITS sequencing. Chemical compositions (cellulose and lignin) of both sound and infected wood were studied. FT-IR spectroscopy was used to collect spectra of decayed and un-decayed wood samples. The results of chemical compositions indicated that T. versicolor reduced cellulose and lignin in similar quantities. Fungal activities in decayed wood causes serious decline in pH content. The amount of alcohol-benzene soluble extractives was severely decreased, while a remarkable increase was found in 1% sodium hydroxide soluble and hot water extractive contents in the decayed wood samples, respectively. FT-IR analyses demonstrated that T. versicolor causes simultaneous white rot in the hornbeam tree in vivo which is in line with in vitro experiments

Dendroclimatology of Quercus castaneifolia (C.A.Mey) in Saravan forests of Guilan

The aim of this research was to review of relation between tree ring width of Quercus castaneifolia C.A.Mey trees and region climate changes in the Saravan forests of Guilan province. For this purpose, the relation between these two factors was studied using Dendroclimatological study and increment borer sampling method. Weather information was obtained from Rasht meteorological station. In this study, the effect of June, July and May-July’s precipitations on tree ring width of Quercus castaneifolia was positive while, the effect of maximum temperature of July, minimum temperature of November, mean temperature of July and mean temperature of November was negative