Experimental variations in functional and demographic traits of Lappula semiglabra among dew amount treatments in an arid region

Abstract

In an arid region, water is the limiting factor for the performance of plants and, hence, the input of water significantly affects the ecological processes. Although the dew phenomenon often occurs in the desert, whether plants can absorb and utilise this water source is still unknown. In this study, we tested the effects of 3 amounts of dew, that is, total natural amount of dew, half amount of natural dew, and no amount of (zero) dew, in order to investigate variations in functional traits and demographic traits in relation to the life history of an ephemeral plant Lappula semiglabra. Results showed that variations in functional traits including plant height, crown area, leaf area, leaf thickness, leaf relative water content, chlorophyll content, and net photosynthetic rate were significantly increased with increasing dew amount. Leaf water potential was significantly decreased, whereas root length and root diameter showed no significant differences among 3 amounts of dew. Demographic traits including survival rate, survival, total age, and mean life expectancy increased with increasing dew amount, whereas the vanish rate percentage, mortality rate, mortality, and fatal number decreased. In combination, our results showed that leaf and stem traits L. semiglabra related to dew absorption increased with increasing of dew amount, and hence, obtained more water, whereas root traits related to uptake of soil water remain unchanged. We conclude that leaves and stem of L. semiglabra can absorb and efficiently utilise dew as a water resource for better suitability in the arid desert region.

High Air Humidity Causes Atmospheric Water Absorption via Assimilating Branches in the Deep-Rooted Tree Haloxylon ammodendron in an Arid Desert Region of Northwest China

“…In arid ecosystems, water is the limiting factor on the ecological performance of plants (Kidron 2010; Yang et al., 2014a; Dai et al., 2015; Yang et al., 2017). In order to survive and grow in an extreme drought environment, desert plants develop special strategies to utilize all sorts of potential water resources (Yan et al., 2015).…”

“…Although some recent studies have reported that the emergence of foliar water uptake might be related to the plant’s root functional type and water availability (Cassana et al., 2016; Ma et al., 2017), which environmental factors actually trigger this water absorption strategy is an ongoing debate among researchers (Goldsmith, 2013; Yan et al., 2015; Cassana et al., 2016; Wang et al., 2016b). In arid desert regions, shallow-rooted herbaceous plants usually absorb atmospheric water, whereas deep-rooted woody plants rely more on groundwater or deep soil water (Pan et al., 2016; Ma et al., 2017; Yang et al., 2017; Liu et al., 2018). The water absorption preferences of desert plants might be determined by the sustainability and magnitude of different water resources.…”

“…Due to their perennial nature, deep-rooted woody plants in arid regions must increase carbon investments in their roots to obtain a large amount of groundwater to satisfy a higher water demand (Dai et al., 2015). In contrast, because they are annual or ephemeral plants, shallow-rooted herbaceous plants only absorb a small amount of atmospheric water to guarantee their growth (Zhuang and Ratcliffe, 2012; Yang et al., 2017). Thus, the difference in predilection for water sources between deep-rooted woody trees and shallow-rooted herbaceous plants may also depend on their water demand and the distinct accessibility of various water sources in arid desert regions (Zhuang and Ratcliffe, 2012; Cassana et al., 2016; Yang et al., 2017).…”

Soil water potential determines the presence of hydraulic lift of Populus euphratica Olivier across growing seasons in an arid desert region

“…The site has a moderate slope and sandy soil (Yang et al 2014). Groundwater is the main water resource of the local ecosystem, and groundwater level ranges from 1.8 to 2.0 m. Sand dunes are observed at 3 km north of the site (Yang et al 2017).…”

Variations in dew moisture regimes in desert ecosystems and their influencing factors

“…Pan et al (2010) also stated that dew can supply water to microorganisms, carpophytes, and shrubs, which accelerated the formation of biological crusts and stabilized the moving sand dunes at the Shapotou Desert experimental research station. Yang et al (2017) expounded the effect of dew on plants with functional and demographic features and provided evidence that the leaves and stems of plants in arid regions absorbed and used dew directly. These studies thus reveal that vascular plants in deserts use dew for survival and growth, indicating the importance of dew as a water source for desert plants.…”