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作者

来源

URBAN FORESTRY & URBAN GREENING,Vol.29,P.49-57

语言

英文

关键字

Built environment; Daily light integral; Photosynthetically active radiation; Urban agriculture; Plant physiology; Leafy vegetables; PHOTOSYNTHETICALLY ACTIVE RADIATION; URBAN GREENERY; GROWTH; TOMATO; PLANTS; SHADE; OPTIMIZATION; PRODUCTIVITY; AGRICULTUR

作者单位

[Song, Xiao Ping; Tan, Hugh T. W.] Natl Univ Singapore, Dept Biol Sci, Singapore 117543, Singapore. [Tan, Puay Yok] Natl Univ Singapore, Dept Architecture, Singapore 117566, Singapore. [Song, Xiao Ping] Swiss Fed Inst Technol, Future Cities Lab, Singapore ETH Ctr, 1 Create Way,CREATE Tower,06-01, Singapore 138602, Singapore. Song, XP (reprint author), Natl Univ Singapore, Dept Biol Sci, Singapore 117543, Singapore.; Song, XP (reprint author), Swiss Fed Inst Technol, Future Cities Lab, Singapore ETH Ctr, 1 Create Way,CREATE Tower,06-01, Singapore 138602, Singapore. E-Mail: xp.song@u.nus.edu; dbsttw@nus.edu.sg; akitpy@nus.edu.sg

摘要

The pursuit of urban agriculture as part of a city's green infrastructure is often a challenge, particularly within compact cities, where there is a limited amount of space between buildings for urban farming and gardening. Instead, such high-rise urban developments present often under-utilized spaces on the vertical surfaces of buildings. A key unknown is the adequacy of light for plant growth. Many leafy vegetables that require high amounts of light form a significant proportion of the staple diet in many Asian countries. We report on the assessment of sunlight adequacy for growing leafy vegetables in a compact tropical city, based on the high-rise and high-density residential environment of Singapore. Leaf physiological traits of seven leafy vegetables were assessed and used to estimate plant light requirements. A survey of photosynthetically active radiation (PAR) along exposed corridors showed that the daily light integral (DLI) value ranged from 2 to 35 mol m(-2) d(-1) under relatively ideal weather conditions during days with abundant solar insolation, and facades that experienced a minimum of half-day direct insolation matched the light requirements of vegetables within the moderate to very high-light categories. With regard to the building form, PAR increased gradually with height, but remains highly influenced by facade orientation and configuration. Owing to the annual north-south oscillation of the sun's path, reduced annual PAR variability and higher total annual PAR at facades, buildings with an east-west orientation will better support continuous vegetable cultivation, especially for basic building typologies without self-shading configurations. However, excessive PAR and temperatures during mid-day hours may hinder plant growth. By highlighting such patterns in levels of PAR, this study confirms the potential for high-rise and high-density conditions in the tropics to support farming using typically under-utilized vertical spaces of residential buildings.