Greenhouse gas emissions from valley-bottom wetlands in an agricultural tropical highland system, Taita Hills, East Africa

Globally, agriculture is one of the main drivers of wetland loss, leading to reduced soil carbon (C) and changes in greenhouse gas (GHG) emissions. In recent decades, wetland loss in Africa appears to be faster than the global losses, at about 43% compared to 35% globally. Valley-bottom wetlands in African highland regions support the livelihoods of >65% of the people who live there, but the effect of agricultural conversion on soil C and GHG emissions is understudied. This study compares GHG emissions between 1 intact, 12 agricultural (converted), and 10 recovered valley-bottom wetlands in Taita Hills, Kenya. Using the static gas chamber method, CO2, CH4, and N2O emissions were measured monthly from April 2023 to date along with soil NO3-N, NH4-N, soil C, and soil moisture. The results indicate that CO2 emissions from the converted wetlands is similar to recovered wetlands (mean = 183 ± 11 SE mg CO2-C m-2 h-1 and mean = 174 ± 13 SE mg CO2-C m-2 h-1 respectively; p > 0.05). This is in contrast with both CH4 and N2O emissions, which showed strong differences (p