Vegetation of the Koobi Fora Region northeast of Lake Turkana, Marsabit County, northern Kenya

Abstract

The Koobi Fora region east of Lake Turkana in northern Kenya ranges in elevation from ca. 360 to 560 m, has a mean annual temperature of ca. 32ºC, and rainfall of ca. 130 mm per year. The area, much of which lies within Sibiloi National Park, supports a diverse flora. Here we provide a list of 367 plant species (361 angiosperms) collected from an area of about 2600 km² between 2012 and 2014, compare the region’s angiosperm flora with the only other documented floras nearby, discuss the principal vegetation types in the study area, and highlight occurrences of some less common plants and plants of restricted distribution. Some 137 plant species (131 angiosperms) are newly documented in this region, none of which have been recorded in the Marsabit region to the east-southeast or in the lower Omo Valley to the northwest. Comparison of the flora of this region with reported floras of the Omo Valley and the Marsabit region show that only 98 species are common to all three areas, and that each area has unique taxa that make up about one-third of its angiosperm flora. Thus each region has a distinct flora, despite having a similar physiognomic appearance. Most of the area is covered by grassland or dwarf shrubland, with about 16% shrubland, and <0.5% riparian forest and riparian woodland combined.

Keywords: Grassland, shrubland, dwarf shrubland, diverse flora, Sibiloi