Evaluation of native herbaceous plants for green roof applications in Istanbul

Green roofs are important components by providing several benefits in urban environments. To achieve these benefits, appropriate plant selection is crucial. Therefore, a study was conducted to evaluate the plant diversity of the Istanbul and Marmara Region of Turkey for potential native suitable plants for green roofs. In this regard, suitable plants for extensive green roofs were investigated among international studies. Detected plant species were compared to taxa in the A2 grid square of Flora of Turkey P.H. Davis (1965-1985). At the second stage of the study, among listed plants, specific open field measurements were performed on 5 selected native plant species including Anthemis tinctoria L., Euphorbia myrsinites L., Prunella vulgaris L., Stachys thirkei C.Koch and Veronica chamaedrys L., which were collected from their natural habitats in Marmara region. The selected plants were placed in two different substrates, each comprising a mixture of lava rock or pumice with municipal waste compost in a volume ratio of 8:2. Measurements, including plant growth index, chlorophyll fluorescence, plant coverage ratio, and plant taxa survival, were conducted over a study period of 53 weeks. All the plant species have reached the phenomenological stage of blossoming in the study. The highest survival rate was observed on Veronica chamaedrys grown in pumice substrates treatments. Prunella vulgaris well adapted to the green roof environment. Despite the number of individual losses, Stachys thirkei exhibited a relatively higher revitalization ability, while Euphorbia myrsinites demonstrated greater drought resistance. A.tinctoria failed to adapt to the limited green roof substrate depth.