Papers
Afficio Undergraduate Journal
Heterogeneous substrate depth supports greater functional diversity with comparable stormwater retention and substrate temperature services to Sedum-dominant green roofs
Winner, Upper Undergraduate Science
Author: Terrell Roulston
Abstract
This study investigates the potential for spatial heterogeneity in substrate depth as a means to increase coexistence of functionally diverse plant species on green roofs. A treatment with heterogeneous substrate depths of 15 cm ridges alternating with 5 cm furrows was vegetated using hydroseed mixtures of forbs and graminoids on the ridges and pre-vegetated mats with succulent species (Sedum dominant) on the furrows. This was compared to a treatment with homogeneous substrate depth of 10 cm covered with pre-vegetative mats of succulents that is representative of a standard extensive green roof design. Both treatments reached high plant cover and successful coexistence was observed between the different growth forms in the mixed vegetation treatment over two growing seasons. The mixed vegetation treatment performed similar stormwater retention and substrate temperature ecosystem services in comparison to the succulent-only treatment. The hydroseeding method showed potential for use in green roof applications. Future research on the effects of substrate depth and topography and hydroseeding on green roofs on a larger scale is needed to determine the validity of these methods in industrial applications.
Published in the Journal of Living Architecture, 7(2) 19-39
Full text PDF: https://doi.org/10.46534/jliv.2020.07.02.019