Abstract:
Tropical forests are known to play an important role in regulating the global climate change and are
important for the global carbon cycle. However, Ethiopian lowland forest contribution to the global
carbon cycle is no more unknown. Among different methods to estimate the biomass and/or carbon
stock in the forest, allometric equations were used in this study. The main objective of the study is to
estimate the biomass and carbon stock of the Metema dry lowland forest which is located in the north
western part of Ethiopia. Three forest sites at Das Gundo, Lemlem Terara and Meka kebeles were
selected purposively to represent the Metema district. Samples were laid systematically at a regular
interval of 400 m by 400 m grid size with two concentric circles. The study area was delineated using
arc Geographic Information System (GIS) software and sample centres were determined with
Geographic Positioning System (GPS). Diameter at breast height (DBH), tree height (H), wood
density (WD) and the combination of these three characteristics were used to estimate biomass and
carbon stock. Estimation of total carbon stock (TC) was carried out by summing up the C from AGC
BGC and DWC (Deadwood) biomass using a conversion factor. From the total C stock, the amount of
CO
2eq
was calculating from total carbon multiplying by 3.67. The result showed that 35 species with
17 families were identified in the study area. Among them, Boswellia papyrifera was found to have the
highest IVI (47%) and followed by Peterocarpus lucens (36%). The mean number of trees ha
xi
-1
was 317
trees. In relation to diameter size, about 75% of the trees were found in <36 cm DBH class. The study
revealed that the density of the tree was decrease toward the higher DBH size class. The main result of
carbon stock showed that C pools of trees above ground carbon, below ground carbon and dead wood
carbon was 15.57, 4.2 and 0.14 tons ha
-1
,
respectively. The total amount of biomass, carbon stock, and
CO
2eq
was 42.39, 19.92, and 73.1 tons ha
-1
,
respectively. Peterocarpus lucens tree species is the
highest contributor in C (5.46 tons ha
-1
) due to its large diameter size. Generally, in the study area,
the largest carbon stock was covered by AGC which accounts 78.2% of the total carbon pool. This
study revealed that the forest in the study area is a good reservoir of carbons pools and it needs an
informed decision to monitor the forest resources. In addition, this study can also provide a basis for
monitoring the biomass carbon stock lose due to deforestation to support the REDD
+
concept in the
Amhara region. Therefore, this forest could be needs protect and boundary demarcation
