Germinación y supervivencia de seis especies nativas de un bosque tropical de Tabasco, México

Abstract

rESUMENSe evaluó la germinación y supervivencia in situ y ex situ de plántulas de Aspidosperma megalocarpon, Eugenia sp., Lonchocarpus castilloi, Manilkara zapota, Ormosia macrocalyx y Rollinia mucosa. En campo se sembraron 2 160 semillas en nueve bloques de 5 m x 20 m distribuidos en bosque tropical, acahual maduro y acahual joven. El experimento se replicó en condiciones de vivero bajo sombra de 40, 60 y 80%. Los tipos de cobertura vegetal no mostraron diferencias significativas en las tasas de germinación y de crecimiento; sin embargo, estos sí influyeron en la capacidad de germinación de A. megalocarpon y O. macrocalyx, y en las tasas de depredación de M. zapota y L. castilloi. En el acahual joven se presentó la mayor depredación de semillas, sin embargo, las plán-tulas remanentes presentaron mayor supervivencia que en las otras coberturas vegetales. En el vivero no se encontró diferencia en la proporción de semillas germinadas, ni en las tasas de germinación y de crecimiento. R. mucosa, fue la única especie que presentó menor supervivencia (42%). Las condiciones ambientales de las diferentes clases de cobertura vegetal en el área de estudio mantienen condiciones adecuadas para el proceso de germinación, crecimiento y establecimiento de plántulas de las especies estudiadas, lo cual permite sugerir su utilización en la rehabilitación de áreas degradadas del bosque original sembrando de manera directa, siempre y cuando se realice de manera inmediata después de la recolecta. Es necesario continuar con estos estudios para promover el uso de especies nativas en la rehabilitación y restauración de bosques tropicales. PALABRAS CLAVE:Condiciones ambientales, depredación, establecimiento, semillas de árboles, tasa de crecimiento, tasas de germinación. ABSTrACTWe 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

Seed germination in <em>Ormosia macrocalyx</em>, an endangered tropical forest tree

“…Brenan (31.19 % day -1 ) (both Fabaceae). Seeds of O. macrocalyx, tested with no pregerminative treatments, germinated after a 10 -11 day period (Table 1), which represents a relatively short period for this species, although it is similar to that reported by different authors for O. macrocalyx (Sautu et al 2007, Pérez-Hernández et al 2011, Román et al 2012. Different responses have been observed depending on particular species.…”

“…Recently formed O. macrocalyx seeds of closed fruits (T1) did not require pregerminative treatments and showed high germination values, as described by Bewley et al (2013) in reference to the seeds contained in recently formed fruits, indicating that they reach physiological maturity followed by an increase in their ability to rapidly germinate, in addition to the fact that the seed coat has still not lignified. Pérez-Hernández et al (2011) found similar results: field and nursery germination was 75 and 87 %, respectively. However, due to the presence of a hard seed coat, the seeds under physical dormancy have germination rates below 1 % (Foster & Delay 1998) or do not germinate at all without a pregerminative treatment (Baskin & Baskin 2004).…”

“…Studies of the reproductive physiology and propagation of Studies of the reproductive physiology and propagation of O. macrocalyx are scarce in Mexico; however, an evaluation of germination in the field and under nursery conditions produced a mean germination of seeds of 75 % after 100 days (Pérez-Hernández et al 2011). Similar data were recorded by Foster & Delay (1998) for the same species under nursery conditions; the process was improved when the seeds were scarified in the hilar region, achieving 100 % germination by the tenth day.…”

“…These results show the great capacity of O. macrocalyx seeds for environmental adaptation, compared to those of other tropical species (Soriano et al 2013). However, other factors such as seed predation and soil humidity (Pérez-Hernández et al 2011) play an important role in seedling survival in the field. Recently formed O. macrocalyx seeds of closed fruits (T1) did not require pregerminative treatments and showed high germination values, as described by Bewley et al (2013) in reference to the seeds contained in recently formed fruits, indicating that they reach physiological maturity followed by an increase in their ability to rapidly germinate, in addition to the fact that the seed coat has still not lignified.…”

“…One such example is Ormosia macrocalyx Ducke (Fabaceae: Papilionoideae), a tree species native to the tropical zones of Latin America (Rudd 1968a), which is classified as endangered in Mexico (SEMARNAT 2010). The species is found in high and medium evergreen forest, as well as in low flooded forest and as secondary vegetation associated with ecosystems featuring different tree species (Ochoa-Gaona et al 2008b, Pérez-Hernández et al 2011. Individuals of this species can reach 50 m in height and between 35 and 60 cm in diameter (Ochoa-Gaona et al 2008b).…”