Microhabitat of the narrow Florida scrub endemic Dicerandra christmanii, with comparisons to its congener D-frutescens

We characterized the microhabitats of the endemic Florida scrub plant Dicer andra christmanii in comparison to random points in the same abandoned sand road and random points in adjoining mature oak scrub lacking plants. We al so compared microhabitat preferences of D. christmanii to its endemic, allo patric congener D. frutescens, a plant with a similar life history growing in similar habitats. Plants of D. christmanii occur in microhabitats with s ignificantly more open canopies, shorter shrubs, and lower litter cover and depth than random points in the scrub. Random points in the abandoned road had intermediate microhabitats. D. christmanii had similar quadrat occupan cy patterns across gradients of litter depth and cover as its congener. How ever, it occurred less often than D. frutescens under closed canopies and n ear tall shrubs. The microhabitat preferred by D. christmanii (canopy cover < 60%, shrub height < 3m, litter cover < 80%, litter depth < 2 cm) is abse nt in mature oak scrub unburned for several decades. Suitable microhabitat can probably be provided by periodic prescribed fire or other disturbances that temporarily remove shrub cover and litter, although the response of D. christmanii to these treatments has not been studied.