Abstract ID: 3.9819 | Accepted as Talk | Talk/Oral | TBA | TBA

Climate change is global challenge that affects montane ecosystems and affecting community livelihoods globally. Mt Elgon ecosystem, Kenya is covered by expansive areas of grasslands that support community pastoralism livelihoods. The changing climatic conditions could adversely affect this ecosystem and the sustainability of their livelihoods. This study sought to establish the effects of climatic variability on natural and semi natural grasslands of Mt Elgon ecosystem between 2000 and 2022. Precipitation data was collected from Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) while temperature data was collected from TERRACLIMATE websites. Data on potential evapotranspiration was collected on a 1-month timescale using the Standardized Precipitation Evapotranspiration Index (SPEI) while data on grasslands was derived from Land & Carbon Lab Global Pasture Watch and analysed using Google Earth Engine and ArcGIS software. There has been a 1.97 km2 annual increase in land under natural semi natural grasslands. Precipitation and SPEI recorded an annual increase of 16.66mm and 0.04 respectively while minimum temperature (Tmin) and maximum temperature (Tmax) recorded an annual decline of 0.009ºC, and 0.007ºC respectively. There were increases in precipitation in all the four seasons. Tmax recorded an increase of (0.001 ºC and 0.0006 ºC) while Tmin recorded an increase of (0.0121ºC and 0.0029ºC) for SON and JJA respectively. There was a strong positive correlation between precipitation and size of land under natural semi natural grasslands (r=0.625 p=0.0014) with SON (r= 0.443, p=0.034). There was a significant negative relationship between SPEI and size of land under natural semi natural grasslands (r= 0.683, p=0.0003). There was a significant negative relationship between SPEI values for December January February (DJF) (r=0.5312 p=0.009) and June July August (JJA) (r=0.4077, p=0.053). Regression revealed that precipitation explains about 36.1% of the size of land under grasslands, SPEI explains about 44%. JJA SPEI could explain about (13%) of the changes in grasslands while DJF SPEI explains (24.8%). There is a strong negative correlation between land under grasslands and the size of land under other land uses (r=-0.99971 p=0.0000). Land Use changes precipitation and SPEI are the major determinants of size of land under grasslands and community livelihoods.