ABSTRACT
Puya raimondii Harms (Bromeliaceae) es una planta monocárpica que puede producir entre 6 y 12 millones de semillas, sin embargo es muy raro encontrar plántulas en su hábitat natural, lo que significaría la existencia de factores limitantes en el proceso de establecimiento. En el presente trabajo muestra los resultados de experimentos para determinar el sustrato más adecuado para el establecimiento de P. raimondii bajo condiciones de laboratorio. Se comparó la sobrevivencia y vigor de plántulas de P. raimondii en los substratos de turba, musgo, turba-tierra y musgo-tierra. El sustrato turba presentó la mayor supervivencia, mostrando que es el más adecuado para el establecimiento de las plántulas, porque mantiene una humedad adecuada y pH estable lo que permitiría que las plántulas presenten un mayor vigor; los sustratos con muy poca (caso turbatierra) o demasiada (caso musgo) retención de humedad afectan negativamente su vigor y desarrollo.
Puya raimondii Harms (Bromeliaceae) is a monocarpic plant, that can produce about 6 to 12 million seeds, nevertheless is very rare to find seedlings in their natural habitat, indicating difficulties for its establishment. In this work, the conditions for establishment of P. raimondii under laboratory conditions were determined carrying out experiments to determine the better substrate. It was compared the survival and vigour of P. raimondii seedling that were transplanted in peat, moss, peat-soil and moss-soil substrates. The peat substrate showed high survival and was better for establishment of seedlings because it maintains steady and suitable humidity and pH conditions, this allowed that seedlings presents a good vigour. Substrates with very little (case peat-earth) or too much (case moss) humidity retention had a negative effect over vigour and development.
ABSTRACT
Germination, establishment and growth of seedlings of tree species Palaquium ellipticum (primary), Actinodaphne malabarica (late secondary) and Macaranga peltata (early secondary) were studied in a humid tropical forest at Nelliampathy, in the Western Ghats of Kerala. While the primary species completed its germination within a brief period of 1·5 months, at the other extreme, early secondary species showed slow germination extending for about 5 months, the late secondary species falling in between. Although, all the species studied showed higher establishment and growth under gaps, the early secondary species were more responsive compared to the primary species. Primary species showed better establishment in undisturbed sites and natural gaps than under selection felled gaps; the reverse was true for late and early secondary species. Survival of seedlings increased with gap size, but sharply declined with gap age. Shoot/root ratio was consistently higher in the early secondary species than in the primary species.