Journal of Tropical Forest Science 18(1): 66--73 (2006)66 GROWTH OF BIG-LEAF MAHOGANY (SWIETENIA MACROPHYLLA) IN NATURAL FORESTS IN BELIZE

trees in natural forests in northwestern Belize were analysed to determine growth rates. Mean diameter increment exceeded 1 cm year–1, with slightly higher growth rates in trees> 50 cm dbh. Inter-individual variation in growth rates was significant, with the fastest-growing individuals growing at rates greater than 2 cm year–1. Inter-annual variation in growth rates was also significant. The diameter growth of 1.21 ± 0.1 cm during a wetter year (1456 mm) exceeded by 75 % the diameter growth of 0.69 ± 0.1 cm during a drier year (1181 mm). The study revealed that mahogany trees as small as 23 cm dbh that were left standing after harvests could be expected to attain the commercial diameter of 60 cm in the 40 years between cutting cycles