Evaluation of Carbon Stock across Different Forest Physiognomy in a Tropical Rainforest Ecosystem at Obafemi Awolowo University Ile-Ife, Nigeria

Abstract

This study investigated carbon stock in above-ground biomass across different physiognomies in Obafemi Awolowo University tropical rainforest ecosystem. This was with a view of increasing the understanding of carbon cycle in tropical rainforest in Nigeria.
 Two 20 m x 20 m plots were marked out in the secondary forest, Tectona grandis and Riparian vegetations. Total enumeration was carried out for the living tree, the Diameter at Breast Height (DBH) of trees ≥10 cm were measured at 1.3 m above the ground and height was also determined using a ranging pole and Haga altimeter.
 Aboveground carbon stocks in standing trees ranged from 218.24 to 318.92 C t ha-1 with the highest value in Tectona grandis plantation. Trees with DBH size class 11-20 cm contributed more to Carbon stock in secondary forest and Tectona grandis plantation, while size class ≥60 cm contributed more in the riparian vegetation. Tectona grandis plantation proved to be better in mitigating carbon in our environment and this result will enhance better estimates of local and regional carbon stock which is crucial to addressing the problems of climate change.

Tree-based carbon sequestration and storage abilities vary in natural and plantation forest ecosystems

“…Nonetheless, this result is consistent with the findings of Pato et al (2017) who reported a higher total biomass in forest (12.85 Mg ha -1 ) than in orchard (5.38 Mg ha -1 ). The variation in tree biomass in this study may be linked to differences in site conditions, tree density, altitude, stand age, tree size class, rainfall pattern and soil conditions (Peichl et al, 2006;Terakunpisut et al, 2007;Gairola et al, 2011;Justine et al, 2015;Arubasa and Odiwe, 2019). The high values for AGB and BGB in the forest ecosystem are connected to the high density of trees with large girths while the low values for these variables in the orchard result from low density of trees having small DBH (Gibbs et al, 2007;Singh, 2014;Gautam and Mandal, 2016).…”