Assessment of a constructed community of native geophytes and sedum species as a habitat analog for extensive green roofs in an urban East Mediterranean environment

Abstract Extensive green roof research has primarily focused on cooler, wetter climates, resulting in a lack of knowledge of Mediterranean conditions. This long-term study addresses this gap by assessing a constructed plant community of native Mediterranean geophytes and Sedum species. While both are individually recognized for their resilience to prolonged dry periods, their combined performance has been underreported. We studied the performance of 15 Mediterranean geophytes combined with one native sedum on an unirrigated extensive green roof for four years. Data collection included plant survival, number of plants, spread, flowering, and new species recruitment. Throughout the study, eight geophytes did not survive, five increased in number, one remained stable, and two declined. Five geophytes readily spread, one occupied the same space, and one decreased. Most surviving geophytes flowered. Sedum spread vegetatively and flowered consistently. Seven native species were recruited. By the end of the experiment, vegetation cover was 100% (47% Sedum,44% geophytes,12% overlapping vegetation,21% new native species). The findings underscore the importance of long-term studies to observe plant dynamics and reveal the possibility of constructing new urban habitats thus contributing valuable insights for green roof development in Mediterranean cities.