Rainwater retention and evapotranspiration as affected by groundcover plants: The influence of leaf morphology

Green infrastructure (GI) as an adaptation strategy to mitigate the effects of climate change has been widely advocated due to their wide range of benefits (ecosystem services). Determining the importance of GI to help alleviate stormwater runoff is made more urgent, when the unpredictability of rainfall, caused by climate change is combined with rapid urbanisation and city densification. In urban areas, increasing volumes, intensities and frequencies of rainfall are exacerbated by soil sealing via hard impervious surfaces, thereby further increasing risks of urban flooding. The potential of trees to capture rainfall, slow down runoff, retain and release moisture has been documented. However, the value of groundcover urban plants with regards to these hydrological activities is less well researched. This research aimed to understand the relationship between plant leaf morphology and hydrological performance, namely rainwater interception, retention (and detention) and the redistribution of moisture via evapotranspiration (ET). The research focuses on groundcover vegetation (ornamental herbaceous plants and sub-shrubs), as these are more commonly used in GI approaches, and can be widely implemented in urban areas.