Varied plant species' responses to climate and environmental change on Mount Kenya after 40 years

Abstract

AbstractTropical alpine areas are some of the most vulnerable areas in the world to climate change. Their plant communities have narrow thermal niches and have limited geographic areas to expand. Here we examine changes in plant species' abundance and distribution in the Teleki Valley (3900–4500 m asl) of Mount Kenya using a spatially explicit vegetation survey from 1980. Vascular plant species were re‐sampled in 35 plots across the valley, and additional size and density data were collected for the two Dendrosenecio species. Overall species richness and diversity were lower in 2021 than in 1980, and the abundance of dominant species had declined. Changes in elevation suggested both upward and downward shifts had occurred. Dendrosenecio keniodendron exhibited a shift towards the valley bottom as well as a change in population structure towards younger individuals. The dominant environmental factors affecting plant composition were similar in both 1980 and 2021, namely elevation, vegetation cover and the presence of D. keniodendron. This keystone species plays a significant role in shaping communities but is undergoing rapid demographic changes, which may have cascading implications on the ecology of the system.