Investigating Effects Of Climate Change On Aflatoxin Causing Fungi Aspergilus Distribution In Maize Over Kenya

Abstract

Climate Change is currently the bane of human existence. From impacting food resources to threatening international security by weakening national defences, climate change has garnered the attention it rightfully deserves. Among the many anticipated changes, projected climate change will impact the agricultural sector and subsequently food security by influencing primary agricultural systems both directly by influencing yields and indirectly by impacting the safety of produced food. This study set out to investigate the effects of climate change on the distribution of the fungi causing aflatoxin – aspergillus- in maize in Kenya. This was achieved by first determining the spatiotemporal variability of past and future climate in Kenya, then determining the spatial distribution of aflatoxin under present climatic conditions and finally by simulating the effects of past and future climate on aflatoxin distribution using a species distribution model. Past temperature and rainfall data was collected from Kenya Meteorological Department and passed through quality control. For future climate, Coordinated Regional Downscaling Experiment (CORDEX) data was used. The data was extracted for two Representative Concentration Pathways (RCP) namely RCP8.5 w/m2 (RCP8.5) and RCP4.5 w/m2 (RCP 4.5). Graphical and statistical analyses were used and the results presented in tables and charts. The rainfall and temperature data at various timescales was subsequently used as predictors and input into MaxEnt a species distribution model. MaxEnt model uses climate variables as well as environmental variables to probabilistically project distribution changes of different naturally occurring species. Temperature and rainfall analysis show that climate has been changing across the years under investigation and will continue to change. Trends of the two variables show a rise in temperatures and a decrease in rainfall over the entire country. Notably, the rate of change of night time temperature is higher than daytime temperatures and rainfall. The results from MaxEnt, show that the distribution is expected to increase geographically under both RCP4.5 and RCP8.5 by the year 2050. This study recommends development of robust adaptation options to cushion the country in the future against the negative impacts of climate change within the agricultural sector such as, development of risk maps for aspergillus occurrence that will give rise to aflatoxin and infect maize.