Infrared heater warming system markedly reduces dew formation: An overlooked factor in arid ecosystems

Abstract

23Dew plays a vital role in ecosystem processes in arid and semi-arid regions 24 and is expected to be affected by climate warming. Infrared heater warming 25 systems have been widely used to simulate climate warming effects on 26 ecosystem. However, how this warming system affects dew formation has been 27 long ignored and rarely addressed. In a typical alpine grassland ecosystem on the 28Northeast of the Tibetan Plateau, we measured dew amount and duration by 29 artificial condensing surfaces, leaf wetness sensors and in situ dew formation on 30 plants from 2012 to 2017. We also measured plant traits related to dew 31 conditions. The results showed that (1) warming reduced the dew amount by 32 41.6%-91.1% depending on the measurement method, and reduced dew duration 33 by 32.1 days compared to the ambient condition. (2) Different plant functional 34 groups differed in dew formation. (3) Under the infrared warming treatment, the 35 dew amount decreased with plant height, while under the ambient conditions, the 36 dew amount showed the opposite trend. We concluded that warming with an 37 infrared heater system greatly reduces dew formation, and if ignored, it may lead 38 to overestimation of the effects of climate warming on ecosystem processes in 39 climate change simulation studies. 40 41