Photosynthetically active radiation — a new unit
نویسندگان
چکیده
منابع مشابه
Photosynthetically active radiation: measurements and modelling
Photosynthetically-active radiation is a necessary input in applications dealing with plant physiology, biomass production and natural illumination in greenhouses. Unfortunately, a worldwide routine network for the measurement of photosynthetically-active radiation is not yet established and it is often calculated as a constant ratio of the broadband solar radiation. This ratio is affected by m...
متن کاملA 5-year study of a new kind of photosynthetically active radiation sensor.
Light-emitting diodes (LED), which are designed as quasi-monochromatic light sources, can also function as spectrally selective photodiodes. This provides a new kind of photosynthetically active radiation (PAR) sensor that is inexpensive and has much better stability over time than interference filters used in some PAR sensors. The action spectrum of photosynthesis in green plants has principle...
متن کاملMapping incident photosynthetically active radiation from MODIS data over China
Photosynthetically active radiation (PAR) is a key input parameter for almost all terrestrial ecosystem models, but the spatial resolution of current PAR products is too coarse to satisfy regional application requirements. In this paper, we present an operational system for PAR retrieval from MODIS data that is based on an idea proposed by [Liang, S., Zheng, T., Liu, R., Fang, H., Tsay, S. -C.,...
متن کاملSimultaneous Assessment of Photosynthetically Active and Ultraviolet Solar Radiation
A new dosimetric package for assessing solar radiation affecting photosynthesis in the visible and ultraviolet wavebands in plant canopies has been developed and tested. The package consists of several detectors sensitive to various wavebands between 290 and 700 nm. For photosynthetically active radiation (PAR), the dosimeter was calibrated for exposures in terms of photosynthetically active ph...
متن کاملIntercepted Photosynthetically Active Radiation Estimated by Spectral Reflectance
Interception of photosynthetically active radiation (PAR) was evaluated relative to greenness and normalized difference [MSS (7 5)/(7 + 5)] for five planting dates of wheat for 1978-79 and 1979-80 at Phoenix, Arizona. Intercepted PAR was calculated from leaf area index and stage of growth. Linear relationships were found with greenness and normalized difference with separate relationships descr...
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ژورنال
عنوان ژورنال: Nature
سال: 1985
ISSN: 0028-0836,1476-4687
DOI: 10.1038/316582a0