Eurasian Journal of Forest Science

1-13

Authors: İlyas BOLAT1*, Ömer KARA2 , Metin TUNAY3

A significant parameter that links plants to soil is microbial biomass. Therefore, measurement of the biologically-active fractions of the soil organic matter, such as microbial biomass C, N and P, is a good way to quantify the quality of the soil. In this study, the seasonal dynamics of microbial biomass C, N and P and associated microbial properties were investigated in the forest’s floor (litter, fermentation and humus) and topsoil (0 – 5 cm) under a stand of Bornmullerian fir (Abies nordmanniana subsp. bornmülleriana Mattf.). According to One-Way ANOVA, the study showed that seasonal changes have a significant effect on the quantities of microbial biomass C, N and P and associated microbial properties in the forest’s floor and soil. For example, the greatest amounts of microbial biomass C, N and P in the forest’s floor and topsoil occurred during summer. Also, seasonal variations have significant effects on microbial biomass C, N and P in the forest’s floor and soil because they alter the climate and chemical characteristics of the soil. Annual releases of C, N and P through microbial biomass were higher in the forest’s floor than in soil. The results of this study indicated that variations in the microbial biomass and basal respiration during the different seasons are related to changes microbial activity.

22-28

Authors: Wang Xiao HONG 1*

Phyllostachys heteroclada olive (P. Het) and Neosinocalamus affinis King (N. Aff) flowered from 2003 to 2007 in Ya’an district in China. We determined metabolism indices of these two bamboo species, and analyzed the key flowering metabolism factors by PCA (principal component analysis). The result showed that GA (Gibberellin), GA/ABA (Gibberellin/Abscisic Acid) were the most important factors of bamboo flowering, followed by starch, amylase activity and soluble sugar, all of which were positively correlated with bamboo flowering. ZT (Zeatin) was negatively correlated to bamboo flowering, it obstructed bamboo flowering and contributed to bamboo flower reversion. Based on the above and former research, we built a bamboo flowering model which showed that bamboo flowering is a long and complicated process. External factors, especially harsh environments such as droughts and high temperatures and internal mechanisms such as GA, GA/ABA, starch, amylase and soluble sugar would possibly accelerate or terminate growth and florescence, making bamboo florescence highly variable.