Factors affecting seed germination and seedling establishment of Harrisia portoricensis (Cactaceae) in Mona Island

Abstract

Germination, establishment, and survival of young plants appear to be the most critical phases in the life cycle of cacti (Godínez-Alvarez et al. 2003). Thus, understand factors affecting processes of germination and establishment in cactus species is important to develop successful conservation and management strategies. Harrisia portoricensis is an endangered cactus endemic to Puerto Rico and geographically restricted to three small Caribbean Islands located to the west of Puerto Rico: Mona, Monito and Desecheo (USFW 1990).In this study we evaluated the effect of contrasting sunlight exposure (open and shade areas), different shade provider species (two native shrubs and one exotic grass species), and variable microenvironmental conditions (temperature, PAR, RH) on the germination, survival, and growth of Harrisia portoricensis seedlings.