Leaf and shoot biomass and shoot growth of Rhododendron understory in Artvin, Turkey

The changes in shoot number, shoot length, shoot diameter, dry shoot, and dry leaf biomass of Rhododendron ponticum L. growing in stands with different closure levels were investigated in 2011 and 2019, Artvin, Turkey. Forty-nine sampling plots with 5 x 5 m dimensions were selected randomly in the study site. ANOVA was conducted to check for the effect of stand closure on measured characteristics. ANOVA results showed that shoot length and shoot diameter in both 2011 and 2019 and cover amount in 2019 differed significantly among closure classes. The relationship between stand closure and the measured Rhododendron ponticum L. characteristics was analyzed using regression. All measured characteristics and biomass decreased with increasing stand closure both in 2011 and 2019. Total average dry leaf and shoot biomass of Rhododendron ponticum L. was 0.80 ton/ha and 7.37 ton/ha in 2011 and 2019, respectively. Significant contribution can be made to fix the energy deficit of Turkey by generating the greatest quantity of energy from forest understory biomass. There is large amount of woody debris and understory herbaceous and shrub species and small trees in forests that are not utilized. This resource needs to be considered and taken into account in future studies focusing on biomass and carbon sequestration.