Germination and survival of six native species in a tropical forest of Tabasco, Mexico

We evaluated the germination and survival in situ and ex situ of seedlings of Aspidosperma megalocarpon, Eugenia sp., Lonchocarpus castilloi, Manilkara zapota, Ormosia macrocalyx and Rollinia mucosa. We established nine blocks of 5 m x 20 m in the field, in which 360 seeds of each species were established in three successional conditions with three repetitions: mature tropical forest, advanced fallows and young fallows. The experiment was replied in a tree nursery using 40, 60 and 80% shade. We found no significant differences in the rates of germination and neither in growth due to variation in the natural cover. However, the rates of germination of A. megalocarpon and O. macrocalyx, and the rates of depredation of M. zapota and L. castilloi were affected by the coverage. Seeds sown in young fallows showed higher depredation, whereas seedling survival was higher here than in the other successional stages. In the tree nursery, no significant difference was found in the proportion of germinated seeds, the rates of germination and in growth. However, R. mucosa showed low survival (42%). The environmental conditions of the forests in Tabasco are under various stages of degradation and it is appropriate to start a rehabilitation program by introducing native species. This study indicates that this could be done by sowing the seeds directly in the forests without first producing seedlings in nurseries, which in turn would reduce the costs. It is recommend continuing research on the seed and seedling performance of other species that could be used to rehabilitate and restore the tropical forest.