Fifty-Nine-Year Performance of Planted Big-Leaf Mahogany (Swietenia macrophylla King) in Puerto Rico

Abstract

This chapter adds to the sparse literature on the performance of planted big-leaf mahogany (Swietenia macrophylla King) at advanced age. The site is in latitude 18° N on a terrace over limestone receiving an average of 185 cm of rainfall annually. The growth period was from 1937 to 1996. Mixed, planted Senna siamea Irwin & Barnaby and Calophyllum calaba L. were mostly girdled between 1977 and 1984. The chapter documents mahogany dbh growth and “efficiency” (annual basal area increment in percent) relative to tree canopy position, the more rapidly growing trees, and abundant naturally regenerated mahogany and associated timber species. A stem analysis provides provisional regressions for taper and heartwood volume outside and inside bark and heartwood alone. The canopy was at 30 m. The mean dbh of the mahoganies at age 59 was 76 cm, with a maximum of 123 cm. The plantation basal area at age 59 was 23 m²ha⁻¹, of which 22 m² ha⁻¹ were mahogany. Inside-bark merchantable volume was about 114m³h⁻¹, of which about 98 m³ha⁻¹ was heartwood. The deduced rotation to 60 cm dbh for dominant and codominant trees is between 29 and 48 years.