Dances with Fire: Tracking Metapopulation Dynamics of Polygonella basiramia in Florida Scrub (USA)

• Published in: Folia geobotanica Vol. 38; no. 3; pp. 255 - 262
• Main Authors: Boyle, Owen D., Menges, Eric S., Waller, Donald M.
• Format: Journal Article
• Language: English
• Published: Institute of Botany, Academy of Sciences of the Czech Republic 01.09.2003
• Subjects: Conservation biology; Endemic species; Landscapes; Metapopulation ecology; Plants; Rosemary; Scrub vegetation; Shrubs; Species; Species extinction
• ISSN: 1211-9520; 1874-9348
• DOI: 10.1007/BF02803197

The regional persistence of species subject to local population colonization and extinction necessarily depends on how landscape features and disturbance affect metapopulation dynamics. Here, we characterize the metapopulation structure and short-term dynamics of Polygonella basiramia. This rare, short-lived perennial herb is endemic to Florida scrublands and lacks a seed bank. Fires create the open sand gaps within a shrub matrix that support this species but also kill established plants. Thus, persistence depends on frequent colonization of unoccupied gaps. We are monitoring population dynamics within and among 1204 gaps distributed among 19 shrub patches. Considerable subpopulation turnover is evident at the gap level with rates of gap extinction exceeding rates of colonization in the first year. Whether declines in overall abundance continue is likely to depend on patterns of disturbance and regional stochasticity in this dynamic landscape. Polygonella is more likely to occupy larger and less isolated gaps, demonstrating that landscape features and disturbance strongly affect metapopulation dynamics. Because Polygonella basiramia displays characteristics, occupancy patterns, and turnover dynamics consistent with metapopulation theory, it represents a model system for studying plant metapopulations.