LAUSR

A key issue in managing for timber production is ensuring the regeneration of commercially valuable species, such as Swietenia macrophylla King (mahogany), which requires in-depth knowledge of the relevant species. This paper reports on the results of direct seeding of mahogany in three slash-and-burn fields during the last year of cultivation, in Betania, Quintana Roo, Mexico. In each field, 121 sowing sites were identified in a 0.25 ha plot, and five seeds were sown in each. Height, diameter and indications of damage by Hypsipyla grandella of all sprouted seeds were recorded at 2, 11, 23, 38, 45, and 58 months after sowing. Shade and soil colour were noted. At 11 months, mortality among seedlings that were alive at 2 months varied among fields but did not vary with shade levels or soil colours. One field was abandoned after 11 months as the research protocol had not been observed. When comparing seedlings alive at 58 months with seedlings alive at 2 months but dead at 58 months, the percentage of survival varied among fields and according to levels of shade, but did not vary with soil colours. The average diameter of seedlings alive at 58 months was influenced by field conditions but did not vary with soil colour or levels of shade. Their average height varied among fields, probably varied with soil colour, and was not influenced by levels of shade. Two months after sowing, 20% of the sowing sites had at least one seedling. Five years later, 63% of those seedlings had died, leaving 7.4% of the sowing sites occupied by a seedling. Seedling height at 58 months varied from 0.3 to 8 m, averaging 2.7 m. Remarkably, none of the 212 seedlings observed showed indications of damage by H. grandella , and the cost of the technique is minimal. Milpa fields in their last cropping year seem to be promising sites for regenerating mahogany from seed in a mixed species tropical forest context.