Demographic differences between road and scrub populations of Florida scrub plants

Background/Question/Methods:

Rare species can colonize anthropogenic habitats. Several federally listed scrub plants occur in gaps within fire-maintained Florida scrub, but also occur frequently along sandy roads. We used IPM models to test the hypothesis that sandy roads provide suitable habitat for several federally listed scrub plants. We compared the demography of scrub and road populations for Dicerandra christmanii, D. thinicola, D. frutescens, Liatris ohlingerae, and Hypericum cumulicola. We assessed recruitment, survival, maximum height, and reproductive output of tagged individuals.

 Results/Conclusions

Demographic differences vary among scrub species, but scrub populations were generally more stable than road populations. Overall, road populations had more variable life spans, earlier flowering, and higher fecundity. The weedier life history in roads may reveal a divergent selective environment or adaptive plasticity. Plasticity or population differentiation may allow these species to persist in anthropogenic habitats within fire-suppressed environments.