Woody species diversity and carbon stock of church forests along age gradient in Dangila district, Awi-zone, Ethiopia

Ethiopian Orthodox Tewahido Churches comprise remnant native woody species around their premises that are important for biodiversity conservation and carbon sequestration. The current study was conducted to examine woody species diversity and carbon stock of church forests along age gradient in Dangila district, Awi-zone, Ethiopia. A list of documented churches was taken from parish council and tourism that categorized into three age gradients i.e., >200yrs, 100–200yrs and ≤100yrs. Then one church was purposively selected from each age gradient. At each of the selected churches, three Gentry transect lines were laid down systematically in three cardinal directions with 120° interval. Tree height and DBH/DSH ≥5cm were measured and saplings were counted within 2m width; whereas, seedling with height <1m was counted from three plots of 2 m × 2 m size along the transect line. Woody species diversity and evenness were computed using Shannon diversity and Evenness indices and carbon stock estimation was done by allometric equation. A total of 91 woody species belong to 45 families and 77 genera were recorded in the church forests. Woody species community structure along age gradients showed an inverted J-shape. The mean Shannon diversity of old, middle and recent church age gradient was 2.85 ± 0.21, 2.74 ± 0.13 and 2.37 ± 0.49 respectively. Woody species richness is statistically significant along age classes. The mean total biomass carbon stock along old, middle and recent age gradients was 64.58 ± 23.58, 65.22 ± 63.47 and 18.65 ± 11.02 metric ton respectively. Hence, old aged churches play a better role for indigenous woody species conservation and carbon sequestration.