Assessing the shading performance of climbing plant canopies

There are many examples of integrating external climbing plants as shading devices to glazed building façades. Apart from providing solar shading, plants can improve the environmental quality such as noise reduction, better air quality and alleviating the urban ‘heat island’ effect. In temperate climates such as the UK, deciduous plants can be used to take the additional advantage of allowing beneficial solar penetration in the winter. There are very limited studies of the shading performance of plant canopies mainly due to the difficulties of measuring the dynamic growth behaviour of plants that influence the solar transmission. The research reported in this paper proposes methodologies and techniques to provide an assessment of the shading performance of a deciduous climbing plant canopy. The research involved the development of the methodologies, the measurement of area coverage of different leaf layers, the measurement of solar transmittances of leaf layers and the integration of experimental results to establish the proposed shading coefficient. The experimental canopy, on which Virginia Creeper was planted, was setup at the University of Brighton and monitored for two years. The research outcomes are reported and significance of the results, potential applications and future work are discussed.