Hydraulic trade-off and coordination strategies mediated by leaf functional traits of desert shrubs

Abstract

Desert shrubs play important roles in desertification control and vegetation restoration, which are particularly affected by droughts caused by climate change. However, the hydraulic strategies associated with hydraulic functional traits of desert shrubs remain unclear. Here, eight desert shrub species with different life forms and morphologies were selected for a common garden experiment at the southeast edge of the Tengger Desert in northern China to study the hydraulic strategies mediated by leaf hydraulic functional traits. Diurnal leaf water potential change, leaf hydraulic efficiency and safety, hydraulic safety margin, hydraulic capacitance, and water potential and relative water content at the turgor loss point were observed to significantly differ among species, suggesting that leaf hydraulic functional traits were strongly associated with species even when living in the same environment. Additionally, shrubs with greater leaf hydraulic efficiency had lower midday leaf water potential and leaf hydraulic safety, suggesting that leaf hydraulic efficiency had a strong trade-off with hydraulic safety and minimum leaf water potential, whereas there was also a coordination between leaf hydraulic safety and the leaf minimal water potential. Moreover, shrubs with higher leaf hydraulic capacitance had greater hydraulic safety margins, indicating coordination between leaf hydraulic capacitance and hydraulic safety margin. Overall, this study indicated that minimal daily leaf water potential, as an easily measured parameter, may be used preliminarily to predict leaf hydraulic conductivity and the resistance to embolism of desert shrubs, providing critical insights into hydraulic trade-off and coordination strategies for native shrubs as priority species in desert vegetation restoration and reconstruction.

Water use strategies of Nitraria tangutorum in the lake-basin region of the Badain Jaran Desert

“…Over the past few decades, climate change has become an important worldwide challenge ( Huo et al., 2022 ). Unprecedented increases in mean temperatures and the frequency of severe droughts and heat events ( Hartmann et al., 2021 ) have contributed to the widespread wilting and death of plant populations ( Guo et al., 2020 ; Hartmann et al., 2021 ; Huo et al., 2022 ). These phenomena have important implications for ecosystem processes and patterns.…”

“…In water-scarce habitats, water uptake strategies are key characteristics that determine plant survival ( Zunzunegui et al., 2022 ), and awareness of desert plant water-use strategies is indispensable. Although desert plants have developed an array of morphological and physiological characteristics to cope with intensive drought events ( Huo et al., 2022 ), it is crucial for desert plants under conditions of water scarcity to alternate water acquisition sources, modulate water potential to maintain hydraulic conductivity ( Huo et al., 2021 ), and improve WUE. As confirmed in previous studies, desert plants, such as Mongolian pine and Haloxylon ammodendron , can alter water sources during the growing season, which is critical for satisfying their water requirements ( Grossiord et al., 2017 ; Wu et al., 2019 ; Zhou et al., 2019 ).…”