Phytocapping of municipal landfills: Evaluating the performance of 21 tree species and two soil depths

"Capping is a mandatory landfill closure procedure to isolate the waste from outside environment, mainly rain water. Clay caps are mostly expensive and often fail to limit entry of water into the waste by developing cracks due to desiccation. To reduce capping costs and to increase environmental benefits, an alternate capping system called ‘Phytocapping’ was trialled at Lakes Creek Road Landfill, Rockhampton, Australia. This system consists of a soil cover and vegetation. Soil cover stores water during rainfall events and the vegetation removes the stored water via transpiration. Trees also act as ‘rain interceptors’ by trapping certain proportion of the rainfall in their canopy. Soil and plants also contribute to reduced methane emission by supporting methanotrophs in their root zone."