Modular green roof plant selection to use in fiber cement roofing

Fiber cement tiles still being a popular and cheap alternative for roofing in urban and rural buildings in Brazil. Thermal insulation provided by this material is not considered efficient in tropical areas. The use of green roofs models over these fiber cement roofing could reduce transfer rates and attenuate the incident solar radiation. Nevertheless, the plant species indicated for this type of green roof must grow well under restricted depth and substrate availability and low maintenance requirement. The objective of this research was to evaluate and select plant species to cover fiber cement roofs, using modular green roof units in the Rain Atlantic Forest Zone of Pernambuco, Brazil. Fourteen species were evaluated considering the characters: persistence rate; soil cover rate; height; biomass of the aerial part; root biomass; inner surface temperature of the fiber cement tiles covered by green modules units with different plant species; and general appearance of the plants after 150 days after planting (DAP). The species Ipomoea asarifolia, Paspalum notatum accessions (PN 02, PN 04, PN 05, PN 06), Sphagneticola trilobata, Tradescantia pallida 'Purpurea' and Tradescantia zebrina despite good development were classified as poorly suitable to green roofs. Callisia repens, Chlorophytum comosum, Ophiopogon jaburan, Paspalum lepton (PL 01), Portulaca grandiflora and Sansevieria trifasciata 'Hahnii' had higher coverage rates and lower internal surface temperature, in addition to a better general appearance. These species can be good choices to compose modular greenroof units to cover fiber cement roofs.