Aboveground biomass, growth and yield for some selected introduced tree species, namely Cupressus lusitanica , Eucalyptus saligna , and Pinus patula in Central Highlands of Ethiopia

摘要

Species of the genera Eucalyptus, Cupressus, and Pinus are the most widely planted tree species in the country in general and in Chilimo dry Afromontane forest in particular. Eucalyptus covers 90% of the total planted forest area in the country. However, only limited information exists in the country regarding aboveground biomass (AGB), belowground biomass (BGB), growth, and yield. This study was conducted to assess the variables on 25 and 30?years of age for three planted species: Cupressus lusitanica, Eucalyptus saligna, and Pinus patula in Chilimo plantation forest, in the Central Highlands of Ethiopia. A two-times inventory was conducted in 2012 and 2017. A total of nine square sampled plots of 400?m2 each, three plots under Cupressus lusitanica, 3 Eucalyptus saligna, and 3 Pinus patula were used for data collection. Data on height, diameter, soil, and tree stumps were collected. Percent C, % N, and bulk density was performed following chemical procedure. The aboveground biomass ranged from 125.76 to 228.67?t?C?ha?1 and the basal area and number of stems from 3.76 to 25.50?m2?ha?1 and 483 to 1175?N?ha?1, respectively. The mean annual basal area and volume increment were between 0.97 and 1.20 m2?ha?1?year?1 and 10.79 and 16.22?m3?ha?1?year?1. Both carbon and nitrogen stock of the planted forest was non-significant among the tree species. The aboveground biomass, growth, and yield significantly varied among the species. Cupressus lusitanica had the highest aboveground biomass, volume, and basal area, while Eucalyptus saligna had the lowest value .To a depth of 1?m, total carbon stored ranged from 130.13 to 234.26?t?C?ha?1. The total annual carbon sequestration potential was 12,575.18?t CO2 eq. Eucalyptus has the highest carbon stock density and growth rate than other species.