Effects of fire on the recruitment of rain forest vegetation beneath Pinus caribaea plantations, Sri Lanka

The purpose of our study was to determine the effect of groundstory fire on natural regeneration within 18–20-year-old Pinus caribaea plantations. Plots were established within three treatment types: unburned, once burned (within the last 5 years), and multiple burned (within the last 5 years). Three plantations within each treatment type were selected. The diversity, stem density, and basal area of vegetation greater than 1.5 m in height were quantified within 10 m × 10 m plots which were replicated four times within each plantation. Vegetation less than 1.5 m was quantified in 1 m × 1 m subplots. Results showed that tree stem density and diversity were greater in unburned treatments than within the two burned treatments. Once-burned plantations were distinguished by lower diversity and density of recruitment yet higher soil fertility as compared with multiple-burned plantations. We attribute this difference to greater fire intensity associated with once-burned plantations. We suggest that plantations that have been established for restoration purposes should be protected from groundstory fire.