Journal Article

Effects of light, moisture, temperature, and litter on the regeneration of five tree species in the tropical montane wet forest of Puerto Rico

Everham, E.M. III (Radford University, Radford, VA.), VanDeGenachte, E, Myster, R.W

1996

Overview

Field experiments were conducted to investigate the effects of light, moisture, temperature, and litter on the regeneration of two early-, one mid-, and two late-successional tropical tree species. High light and litter seem to be universally good cues for regeneration, increasing seed/seedling survival for all species except for Cecropia (an early-successional species) whose small seeds may not be able to penetrate the litter layer. In addition, the high temperature environment in both artificially shaded and nonshaded areas of a natural gap exhibits less seed loss, an increase in the percent and rate of germination, and an increase in seedling survival for Dacryodes (a late-successional species), than the lower temperature environment under an intact canopy. Low soil water is also a good cue for Dacryodes germination as it is for Prestoea and Cecropia. Finally, the lower temperature environment found under the forest canopy (compared to the natural gap) leads to less seed loss and more germination for Guarea (a mid-successional species). Our results suggest that a good patch for regeneration of many species in this forest, early- as well as late-successional species, would have high light and a litter layer that moderates temperature and moisture extremes. The substantial variation in suitability among regeneration filters and species could: (1) contribute to low establishment success, i.e., most dispersed propagules do not become trees, (2) make it difficult to group species into germination strategies, and (3) make it hard to generalize about a net effect of any specific environmental variable on establishment. We suggest that tropical disturbances should be viewed in terms of their impact on a variety of environmental cues, which may signal germination and impact subsequent growth and survival

• Publisher: American Botanical Society,Botanical Society of America, Inc
• Subject: AGUA DEL SUELO / ARALIACEAE / Arecaceae / BOSQUE TROPICAL HUMEDO / BOSQUES / Botany / CECROPIA / Cecropia schreberiana / CHOIX DE LA DATE / CONTENIDO DE HUMEDAD / CRECIMIENTO / CROISSANCE / Dacryodes / EAU DU SOL / ECOLOGIA FORESTAL / ECOLOGIE FORESTIERE / ELECCION DE LA EPOCA / Field tests / Forest ecology / Forest litter / Forest regeneration / Forests / FORET / FORET TROPICALE HUMIDE / GERMINACION / GERMINATION / Guarea / Guarea guidonia / HOJARASCA FORESTAL / Light / LITIERE FORESTIERE / Litter / LUMIERE / LUZ / MELIACEAE / Montane forests / natural regeneration / PALMAE / Plant reproduction / Plant species / PLANTULAS / PLANTULE / PORTO RICO / Poultry litter / Prestoea / PUERTO RICO / REGENERACION NATURAL / REGENERATION NATURELLE / REGION D'ALTITUDE / Reproductive Biology / seed germination / seedling growth / Seeds / Shefflera / Soil water / TEMPERATURA / TEMPERATURE / TENEUR EN EAU / Trees / tropical montane wet forest / Tropical rain forests / water content / ZONA DE MONTANA