Managing plant-soil-water systems for more sustainable landscapes

The ecosystem services that can be delivered through green infrastructure are now highly valued. Functions including outdoor recreation and amenity, public health and safety (microclimate modification), community networking, contact with nature, natural resource protection and food production, provided through green space, contribute to the liveability of urban areas. Storm water harvesting schemes are increasingly important in the provision and maintenance of urban green space but the success of these systems relies upon the selected plants being suited to the site and the growing environment, healthy soil/media environments, appropriate soil moisture regimes, fit-for-purpose water quality and secure water supplies. Healthy plant growth, and hence the provision of ecosystem services, is influenced by dynamic relationships between these functions, but in particular hydrological processes. Quantification of the hydrological processes is essential to providing a sound foundation for the design and management of green infrastructure. Adoption of tools, such as soil moisture sensing and daily ET data provide valuable insights into soil water extraction rates by plants, effectiveness of rainfall and irrigation, identification of tree root activity and soil root zone layers, estimation of deep soil water storage potential and determination of trigger points, based on plant stress levels, to inform irrigation scheduling. This paper outlines key factors in green infrastructure design and management to ensure that they provide valuable, effective and sustainable services, based on defined and measurable landscape outcomes, an understanding of each of the water cycle processes and examines strategies that maintain healthy soil environments, optimises storm water use and implements best management practices in irrigation and water management.