Coppice regrowth in a disturbed tropical dry limestone forest in Jamaica

Abstract

The Hellshire Hills are an extensive area of tropical dry forest over limestone, located on the south coast of Jamaica. Despite being a protected area, they are subject to encroachment and clearance by charcoal burners, leaving a relatively pristine core within more disturbed areas of forest. Future management requires a consideration of the forest’s resilience to such disturbance, and this study reports on coppice regrowth following clearance. The number of coppice shoots and the length and diameter at breast height (DBH) of the leading shoots were measured on tree stumps 14 months after they were cut in an experiment. Coppice regrowth after cutting was measured on a total of 476 stumps, representing 51 species. Coppice production and growth was vigorous as there was an extremely high incidence of coppice regrowth among and within the species in this forest after it had been cut. Initial regrowth was high with the diameter recovered by the leading shoots after 14 months approximating to 29% per year. Of the 51 species sampled three did not coppice at all and the average percent of individuals found with shoots within each species was 81%. The height and diameter of the leading shoots was significantly different among the species and the average height recorded of the leading shoots was 114 cm while the average diameter recorded was 10 mm. Larger sized stems (>10 cm DBH) on average produced more coppice shoots and larger sized shoots than smaller sized stems (<10 cm DBH) while smaller sized stems recovered more biomass than larger sized stems irrespective of species. The average diameter of the leading shoots decreased significantly with increasing shoot densities. At the species level there was a significant relationship between stem diameter and the number of shoots produced in seven of the 27 species analysed and three species returned significant relationships between stem diameter and average height of leading shoots. Coppice regrowth clearly offers considerable resilience to disturbance in this dry forest where successful regeneration by seed is highly susceptible to rainfall seasonality. However, the different abilities of species to produce coppice shoots will likely affect long-term species diversity if the present rate of clearance continues.