Effects of Human Generated Fires on Soil Organic Carbon Stocks under Different Vegetation Types in Northern Ghana

Abstract

This study examined the effect of fires on the distribution of SOCS under different vegetation types. Soil samples were randomly collected on 34 plots and 24 sample points at depths 0–10 cm, 10–20 cm and 20–30 cm per plot in Northern Region of Ghana. Experimentally, 50m x 50m plots were marked out on burnt and unburnt lands under four different vegetation types. % C and bulk density were estimated using Walkley Black and core methods respectively. Results show that SOCS insignificantly (P>0.05) varied under the vegetation types with close savanna woodland (CSW) recording the highest of ~16.7t/ha on unburnt sites and ~19.4 t/ha on burnt sites while Grass/herbs with scattered trees and shrubs (GHST) recoded ~7.9 t/ha and ~9.4 t/ha on unburnt and burnt sites, respectively. The difference in % C and bulk density across depth were statistically significant (P<0.05). A strong negative correlation existed between bulk density & %C and bulk density & SOCS. We conclude that contrary to previous studies fire significantly (P<0.05) increased SOCS on fallow lands depending on fire temperature. However, vegetation types in the savannah of Ghana were observed to have an insignificant impact on the quantity of SOCs.