Integrating demography and fire management: an example from Florida scrub

Abstract

In this work, I have used life-history and demographic data to define fire return intervals for several types of Florida scrub, a xeric shrubland where fire is the dominant ecological disturbance but where fire suppression is a major issue. The datasets combine chronosequence and longitudinal approaches at community and population levels. Resprouting shrubs, which dominate most types of Florida scrub, recover rapidly after fires (although their limits under frequent fires are not well known) and also increasingly dominate long-unburned areas. These dominant shrubs can prosper over a range of fire return intervals. Obligate-seeding scrub plants, which often have persistent seed banks, can be eliminated by frequent fire but often decline with infrequent fire. Population viability analyses of habitat specialists offer more precision in suggesting ranges of appropriate fire return intervals. For two types of Florida scrub (rosemary scrub and oak–hickory scrub), plant-population viability analyses narrow the interval and suggest more frequent fires than do previous recommendations, at intervals of 15–30 and 5–12 years, respectively. Variation in fire regimes in time and space (pyrodiversity) is recommended as a bet-hedging fire-management strategy and to allow co-existence of species with disparate life histories.