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   Institute of Evolution



Research at the Center.

Housed within the Institute of Evolution and Faculty of Natural Sciences, our primary focus is on understanding what contributes to biodiverse roofs. To understand how we can maximize the biodiversity contribution made by green roofs, we need to draw from conceptual evolutionary biology and ecology. Reciprocally, green roof habitats provide opportunities to develop and test evolutionary and ecological theories. We study how factors such as substrate type and depth, topographic heterogeneity, plant diversity and identity, gray water irrigation, nutrient regimes and canopy cover of photovoltaic panels interact to affect plant and animal communities, as well as other factors such as drainage and electrical production efficiency of photovoltaic panels.

In addition to being a center of conceptual and applied research, it serves as outreach for educating the public and, in cooperation with industry, government agencies and NGO’s, to promote and develop green roofs in Israel.

Recent studies: 

-Survival and growth of perennial plants on non-irrigated (extensive) green roofs:
Project leader: Dr. Aaron Rottenberg
The main challenge in creating and maintaining non-irrigated (extensive) green roofs in Israel and other semi-arid regions is choosing suitable plant species to withstand harsh conditions. Annual plant species remain dry and unattractive or disappear altogether for seven months of the year and thus are not functional or aesthetic. Also, most of both local and exotic perennial plant species do not survive in the non-irrigated shallow soil of green roofs during the same long dry period. Only few perennial species could be considered suitable candidates for the extensive green roof in this study. The main goal was to select drought-tolerant species and to measure survival, growth and coverage of green roof plots during all months of the year. Five perennial plant species were carefully chosen for the study. Plant area coverage, as well as arthropod communities, were observed during 18 months (January 2018-July 2019) in all the research plots.

-CO2 absorption by green walls and indoor air quality:

Project leader: Dr. Har’el Agra

This study is the result of the collaboration between the Kadas Center and Vertical Field Ltd., a company specializing in green walls and vertical agriculture. Green walls can improve indoor air-quality by reducing concentrations of carbon dioxide (CO2) and other air pollutants. This study commenced in December 2018 and ended in April 2019. It focused on the spider plant, Chlorophytum comosum, and devil’s ivy, Epipremnum aureum, both common green-wall plants that have been found to be efficient CO2 absorbers. Both species have multiple variants with varying degrees of leaf green-white segmentation. Since photosynthesis depends on the concentration of leaf chlorophylls, it was hypothesized that green variants are more efficient carbon absorbers than green-white variants. In addition, we tested the hypothesis that the photosynthetic rate of plants is affected by pot volume, as suggested by previous studies. We used a portable gas exchange system to determine the rate of photosynthesis of the study plants. The following article describing this study is currently under review:

-Photovoltaic panel integration on an irrigated green roof

Project leader: Dr. Bracha Schindler

The integration of photovoltaic panels (PV) with green roofs is predicted to provide benefits for both the panels and the green roof, as the green roof cools the panels and the panels provide shade that is beneficial for some species. In this study, we examined the reciprocal effects of the green roof and PV on an irrigated green roof in a Mediterranean climate. In a replicated experiment, we included plots with a green roof versus a bituminous roof surface and green roof plots with and without PV. Irrigation was expected to maintain plant growth during the dry summer and promote cooling of the PV when temperatures are highest and PV efficiency is expected to decline.



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