Growth of the Chilean plants Haplopappus macrocephalus and Selliera radicans on an extensive modular green roof system under three irrigation regimes

Abstract

© 2017, Universidad de Tarapaca. All rights reserved. There is an increasing trend in Chile to establish green roofs in urban areas using native plants in order to reintroduce the lost flora in the cities. Most Chilean cities are located in the central zone, where mediterranean climate predominates with minimal rainfall during the hot summer period. Thus green roofs require an irrigation system to provide sustainable plant growth. The present study evaluated the effect of different irrigation regimes (two irrigations per day; one irrigation per day and four irrigations per week) on the growth of two native species, Haplopappus macrocephalus and Selliera radicans, planted in Talca. The study utilized green roof modules made with recycled and shredded ethylene vinyl acetate (EVA), with a drainage system capable of retaining a portion of the runoff water. Plant survival was 100% in H. macrocephalus and 96% in S. radicans. Plant growth was similar for all irrigation treatments as well as flowering for both species. The only differences observed were in dry matter accumulation for H. macrocephalus, where irrigation once or twice a day increased aerial dry weight compared to irrigation four times a week. In contrast, root dry matter accumulation was similar for all three irrigation treatments. Both species would be suitable for Talca green roof plantings; irrigation can be applied four times per week in order to save water resources without endangering plant growth or flowering.