Fire occurrence on Mount Kenya and patterns of burning

Abstract

Tropical alpine areas serve important roles in the areas of biodiversity, hydrology, and carbon storage. These unique ecosystems are threatened by climate change and fire. Mount Kenya is one such area that has been faced by numerous large fires in recent years. The extent and patterning of these fires is analyzed in this study. Fires for the last 16 years were mapped with satellite imagery to create a fire history map and determine the current fire regime for the mountain. In addition, the major moorland fires over this period were mapped for severity using a spectral index. The results show that fire is a dominant force in Mount Kenya burning over 10% of the mountain in the past 16 years, and 33% of the alpine moorland areas. The fires are concentrated in the lower moorland just above the treeline, and likely play a role in determining the position of the treeline. The severity of the fires is largely low to moderate. There is no clear trend in fire quantity over this period, but the seasonality appears to have shifted from a bimodal pattern to a unimodal pattern. Also the inter-annual variability has increased considerably in the past few years. It is not clear how the vegetation, and in particular the Ericaceous vegetation which characterizes these moorlands, will respond to changing fire patterns.