Evaluation of the effects of various factors on aboveground and belowground biomass storage capacity of Rhododendron ponticum

Abstract

Although there is a great potential for Rhododendron ponticum (common rhododendron) to naturally spread throughout the entire Black Sea region of Turkey, there has been no generic biomass study. Therefore, this study was carried out to determine the biomass amounts of common R. ponticum populations and how that biomass differs according to certain vegetation and habitat characteristics. Data were obtained from 36 plot areas in the Black Sea region of Turkey: 18 from Giresun and 18 from Bartin. The data were afterwards grouped in terms of altitude, dominant exposure and vegetation height factors, to reveal the change of R. ponticum biomass accordingly. The data obtained showed significant variation; therefore, mass values are expressed as mean values. The potential relationship between the afore-mentioned factors and the amounts of biomass was examined by using the analysis of variance. Results showed that the highest biomass amount occurs at 0-500 m in altitude, with a mean biomass of 40,035 kg ha^-1. Regarding dominant exposure and biomass amounts, the mean biomass of the R. ponticum population was found to be 38,185.6 kg ha^-1 in sunny exposure and 35,185 kg ha^-1 in shady exposure. Regarding vegetation height and biomass amounts, 38,820.7 kg ha^-1 was the highest biomass when the vegetation height was 2-2.5 m. Overall however, the analysis of variance for exposure, altitude and mean height of vegetation revealed no significant differences among the groups. It can be concluded that using average values to estimate biomass storage capacities of R. ponticum populations is the most reasonable way to proceed at this time.