INTRODUCTION
Dew
is considered a vital vegetative water source in semiarid and arid areas
(Beysens 1995, Agam & Berliner 2006, Wang et al. 2017). In such
environments, dew has significant effects on relative humidity, vapor
pressure deficits and nutrient cycling (Goldsmith et al. 2013, Wang et
al. 2019), and these factors influence plant photosynthesis,
transpiration and other important ecological processes (Benasher et al.
2010, Wang et al. 2017).
Dew formation in ecosystems is affected by microclimatic parameters
(e.g., air temperature, relative humidity and vapor pressure deficit)
and plant morphological features (e.g., aboveground biomass, leaf area,
leaf roughness and plant height). These factors change under different
climatic conditions and are associated with different plant species or
functional groups (Agam & Berliner 2006, Hao et al. 2012). Thus, it is
expected that rapidly changing climates will significantly affect dew
formation (Walther et al. 2002, Xiao et al. 2013, Li et al. 2018).
To simulate climate warming, an infrared heater warming system is widely
used to address the potential impacts of climate warming on ecosystems
in the field (Liu et al. 2018, Song et al. 2019, Ettinger et al. 2019).
However, there are differences between artificial and natural warming
(De Boeck et al. 2015, Korell et al. 2019), and the effects of
artificial warming have the potential to influence dew formation
(Wolkovich et al. 2012). As a result, the observed changes in ecological
processes in various climate change studies are likely attributed, to
some extent, to altered dew amounts, misrepresenting the effects of
warming on ecosystem processes.
Few studies on dew research have been conducted in the context of
climate change, and global warming experiments have not reported the
effects of climate change or plant traits and functional groups on dew
formation or even considered the effects of dew as a long-term factor
affecting soils and plants as well as ecosystem processes during the
course of climate change (Tomaszkiewicz et al. 2015, Li et al. 2018).
Therefore, the impacts of artificial warming, plant traits and
functional groups on dew formation urgently need to be revealed to
better understand the impacts of warming on ecosystem processes (Korell
et al. 2019).
The objectives of the present study were to (1) address how the widely
used infrared heater warming system affects dew amount and duration and
(2) elucidate whether plant functional groups, which are expected to
shift under future warming, affect dew formation under ambient and
warming conditions. Our results will aid in the understanding of the
characteristics of dew formation under a warming climate in the future.