Evaluating Native germplasm for extensive green roof systems for semiarid regions

Abstract

Extensive green roofs (EGR) spaces constitute harsh and stressful growing environments, and consequently a limited range of plants species that can be routinely used there. The habitat template hypothesis suggests that EGR can be analogous as natural environments, what makes native plants as an alternative for these conditions. This paper aimed to assess the potential use of 15 native plants from Córdoba Province (Argentina) for green roofs, based on cover ability, survived rates and health status observations during a period of 414 days. Sedum acre L. was used as the control. Glandularia x hybrid, Phyla nodiflora (L.) Greene, Melica macra Nees, Eustachys retusa (Lag.) Kunth and Grindelia cabrerae Ariza kept up a 60% of coverage during all the period of study. The first two species had an outperformed green coverage (at 72th day; 95% and 98% respectively) in relation to the control species (Sedum acre; 87%). Eustachys retusa and Grindelia cabrerae grew progressively and kept their coverage constant proximally to 65%. Sedum acre, Grindelia cabrerae, Hysterionica jasionoides Willd, Melica macra, Phyla nodiflora, stood out in plant survival rates; but S. acre suffered changes in health status throughout the evaluation period, especially with low temperatures or at high humidity conditions. It is necessary to underline the reseeding potential of Eustachys retusa, a process that could guarantee perpetuation of the species on EGR.

The native - exotic plant choice in green roof design: using a multicriteria decision framework to foster urban biodiversity

“…In addition, by experimentally evaluating 12 candidate species obtained after applying the MCDA, we showed that native species performed better than exotics according to what is expected under the “adaptation argument” (Butler et al, 2012). These results constitute new evidence for a South American city where green roof technology and, especially, the selection and use of native vegetation are taking their first steps (but see Jaramillo Pazmino, 2016; Cáceres et al, 2018). In addition, given that the robustness of the MCDA procedures was tested in only 5% of the studies reviewed in conservation (Adem Esmail and Geneletti, 2018), our results contribute to addressing the utility of this approach to select plants for extensive green roof design aimed to favour urban biodiversity.…”

“…Regarding the relative success of exotic versus native plant roof cover, most examples are from the northern hemisphere with no clear performance advantages of any group (Butler et al, 2012). For its part, other temperate, semi-arid and arid regions of the world may provide good candidates of native species other than the traditional Sedum vegetation roofs' cover (e.g., Cáceres et al, 2018;Yee et al, 2021), but the promising horizon of better native alternatives remains to be tested within a common comparative framework. This is crucial to address the relative value of a given plant on the basis of its origin.…”

“…Until now, decisions regarding plant species’ origin in green roofs have been evaluated in relation to its roof adaptability but not including the plants’ potential to foster beneficial arthropods in an integrative multicriteria decision framework. Moreover in South American cities, where green roof technology and especially the selection and use of native plant vegetation are still in its infancy (but see Jaramillo Pazmino, 2016; Cáceres et al, 2018), the use of decision tools would be helpful to integrate previous knowledge on this matter with novel conservation goals.…”

Polvo De Ladrillo Como Sustrato Para Techos Verdes Extensivos

“…fruticosus en Atenas (Grecia) (Nektarios et al, 2011); Carpobrotus rossii L. en Adelaida (Australia) (Razzaghmanesh et al, 2014); Phyla nodiflora L., Grindelia cabrerae Corn., Eustachys retusa Lag. y Glandularia x hybrid en Córdoba (Argentina) (Cáceres et al, 2018). La incorporación de plantas nativas a la vegetación de un techo extensivo se debe a su adaptación a las condiciones climáticas locales, proporcionan un hábitat familiar para la fauna local y aumentan la biodiversidad del techo (Nektarios et al, 2011).…”

Capacidad germinativa de Poaceae nativas de las sierras de Córdoba (Argentina) afectadas por incendios

“…La falta de disponibilidad de semillas y el desconocimiento de la capacidad germinativa de semillas de herbáceas nativas se presentan como limitantes para su uso en restauración y en general se recurre a especies exóticas con protocolos de germinación conocidos que actúan como otro factor de alteración del ambiente natural y compiten con las nativas. En este sentido, se sabe que E. retusa tiene un alto poder germinativo y que se resiembra naturalmente (Cáceres et al, 2018) y que S. condensatum tiene un banco de semillas persistente a largo plazo (Ferri et al, 2009). Sin embargo, se desconoce la capacidad germinativa de las semillas de estas especies luego de ser sometidas a tratamientos pregerminativos, que podrían emplearse para lograr altos porcentajes de germinación en programas de siembra y restauración de ambientes degradados.…”