Urban heat islands as agricultural opportunities: An innovative approach

Many cities are experiencing an Urban Heat Island (UHI) effect and a substantial amount of research has focused on ameliorating those conditions. However, few studies have proposed taking advantage of them. This research investigated the potential for growing food crops in hot urban microclimates that would not grow successfully in the surrounding rural area, Growing degree days (GDDs) and grapevine winter hardiness were used to simulate how the UHI might affect plant growth in Toronto, Canada. Modelled leaf temperature was used to analyze urban microclimate variability and implications for plant growth. GDDs in Toronto have increased from an average around 1000 in the mid-1800's to an average around 1500 today, but have remained unchanged in the rural area outside the city. The urbanization of Toronto has caused longer, hotter growing seasons, and warmer winters. Given the appropriate microclimate combined with UHI effects Toronto could likely support the growth of warmer-climate crops that would not otherwise grow successfully in Ontario. (C) 2017 The Authors. Published by Elsevier B.V.