Plant leaf traits predict green roof ecosystem services

Background/Question/Methods

Green roof services of thermal cooling and stormwater capture reduce energy and infrastructure requirements however plant species vary in their service provision. Ecosystem services have elsewhere been explained using plant traits. We looked to plant traits as potential predictors for green roof services of thermal cooling and stormwater capture. In order to determine which traits act as drivers for green roof services, we measured leaf, plant and module-level traits as well as surface temperatures and stormwater capture for 22 plant species grown in monoculture in green roof modules and performed a path analysis.

Results/Conclusions

From path analysis, we found surface temperature to be driven by module-level characteristics of net evapotranspiration, albedo and canopy leaf area index and stormwater capture driven by net evapotranspiration. Module-level traits were in turn driven by plant and leaf-level traits. Our results indicate that easy-to-measure leaf-level traits can be utilized to select plant species with the goal of maximizing provision of stormwater capture and/or thermal cooling on green roof systems.