PS 87-261
Drought tolerance and evaporation in green roof vegetation: Effect on plant species and water availability
Vegetated green roofs have been an increasingly popular method for mitigating the negative environmental impacts of urbanization. Drought is an important environmental stress in green roofs that adversely affects plant growth and causes a reduction in growth. The study was conducted to clarify the different of oxidative damage to environmental stress with 8 green roof plants including 2 Korean endemic species and to calculate the evaporation rates of each test plants. Soil moisture contents, relative water contents of plants and Biomass of plants were measured through June, 2013. Also, we investigated the different response of oxidative damage to drought stress to evaluate thermal environment and plant growth of green roof system in Seoul.
Results/Conclusions
The result of selecting high functional green roof plants was that Aster koraiensis and Iris psudoscorus showed high evaporation rates and medium level of drought tolerance. Sedum takesimense has high level of drought tolerance, but lower evaporation rate (2.5kg/‡u) under control stress than the evaporation rate(2.6kg/‡u) of Aster korainesis under heavy drought stress. Constructed-wetland roofs offer thermal benefits, a low amount of required irrigation, high tolerance of drought and flood, and flood-control capacities. Therefore, constructed wetlands are a reasonable choice for green rooftop systems. Most of intensive green roof systems showed better plant growth (lower drought stress) and higher performance of temperature reduction than extensive green roof systems in Seoul. The effects of green roofs as temperature reduction and rain retention ability showed significant differences by the species of green roof planting, the depth of soil, the system methods and the microclimates.