Evaluation of native species for use in green roofs in the semiarid Mediterranean region of Central Chile.

摘要

The main objective of this research was to test Chilean native plants under green roof conditions using an appropriate substrate of local origin. Sixteen native species from the Mediterranean region of the country were chosen and grouped into four landscape groups (three adapted to full sun and one to partial shade) and planted under green roof simulation inside the urban area of Santiago. Two different substrate mixes and 9 cm of depth were used to grow the four landscape groups. As a control, replicates of each association were grown under garden situation in the same location and without soil depth limitations. The parameters analyzed were percentage of survival, aerial growth, rate of coverage, time of flowering, competitiveness ability against weeds as well as maintenance cost and quantity of water required. During the first growing season was possible to observe that weed pressure was 8 times less than in the garden controls. In the full sun association Glandularia berteri has performed exceptionally presenting frost resistance and early and extended blooming. Also in that association Geum magellanicum performed above the average. In the partial shade association Cotula scariosa has shown a fast growth and frost resistance and the larger coverage rate. In general, the four plant groups shown to be suitable to be grown under green roof conditions with the exception of Plumbago coerulea that was not frost resistant. Future evaluations will be performed at least for another two growing seasons.