Data on vegetation structure on the study plots of the Kilimanjaro Research Unit

We established eight subplots per plot. These subplots consisted of circles with a 20-m radius in densely vegetated habitats (savanna and all forest habitats) and 35.5 m × 35.5 m squares at Helichrysum plots, covering the same sampling area in all habitat types. We quantified vertical vegetation heterogeneity, canopy height and canopy closure on every subplot in the warm dry season (December to March) and in the cold dry season (July to October). To obtain vertical vegetation heterogeneity, we first estimated the vegetation cover in layers at 0, 1, 2, 4, 8, 16, 32 and 64 m above ground and then calculated the Shannon–Wiener diversity index across these eight strata. Canopy height was measured with a laser rangefinder as maximum canopy height above ground. Canopy closure was measured as the mean percentage of closed cells from four spherical canopy densitometer readings taken at the centre of each subplot in the four cardinal directions.