Leaf size variations in a dominant desert shrub, Reaumuria soongarica, adapted to heterogeneous environments

Abstract

The climate in arid Central Asia (ACA) has changed rapidly in recent decades, but the ecological consequences of this are far from clear. To predict the impacts of climate change on ecosystem functioning, greater attention should be given to the relationships between leaf functional traits and environmental heterogeneity. As a dominant constructive shrub widely distributed in ACA, Reaumuria soongarica provided us with an ideal model to understand how leaf functional traits of desert ecosystems responded to the heterogeneous environments of ACA. Here, to determine the influences of genetic and ecological factors, we characterized species‐wide variations in leaf traits among 30 wild populations of R. soongarica and 16 populations grown in a common garden. We found that the leaf length, width, and leaf length to width ratio (L/W) of the northern lineage were significantly larger than those of other genetic lineages, and principal component analysis based on the in situ environmental factors distinguished the northern lineage from the other lineages studied. With increasing latitude, leaf length, width, and L/W in the wild populations increased significantly. Leaf length and L/W were negatively correlated with altitude, and first increased and then decreased with increasing mean annual temperature (MAT) and mean annual precipitation (MAP). Stepwise regression analyses further indicated that leaf length variation was mainly affected by latitude. However, leaf width was uncorrelated with altitude, MAT, or MAP. The common garden trial showed that leaf width variation among the eastern populations was caused by both local adaptation and phenotypic plasticity. Our findings suggest that R. soongarica preferentially changes leaf length to adjust leaf size to cope with environmental change. We also reveal phenotypic evidence for ecological speciation of R. soongarica. These results will help us better understand and predict the consequences of climate change for desert ecosystem functioning.

Reaumuria soongorica-plant model to understand drought adaptive mechanisms of xerophyte and their potentials in improving stress tolerance in plants

“…Stepwise regression analyses further indicated that variation in leaf length variation was mainly affected by latitude. These indicate that R. soongarica preferentially changes leaf length to adjust leaf size to cope with environmental change (Fan et al, 2020). Low salt stress condition (200 mM) signifcantly promoted the vegetative growth in total leaf area, total fresh weight, and root shoot ratio of R. soongorica seedlings .…”

“…Morphological traits: Drought is one of the detrimental environmental stresses that affect morphological growth in plants. Fan et al (2020) used 30 wild populations of R. soongarica and 16 populations grown in a common garden as material to reveal the influence of genetic and ecological factors on leaf morphology. The study revealed that leaf length, width, and leaf length to width ratio (L/W) of the northern lineage were significantly larger than other genetic lineages based on principal component analysis.…”

Variation in Leaf Functional and Plant Defense Traits of Introduced Eucalyptus Species across Environmental Gradients in Their New Range in Southern China

“…Specifically, annual average temperature and annual average precipitation are highly correlated with latitude, and are thought to be important drivers underlying the relationship between leaf traits and latitude [40]. As early as the 19th century, biogeographers noticed that leaves in low latitudes were usually larger in size [41], with leaf size decreasing with increases in altitude [42]. However, the relationship between leaf size and environmental factors is not fixed, and may vary in different regions or different species [41].…”

“…As early as the 19th century, biogeographers noticed that leaves in low latitudes were usually larger in size [41], with leaf size decreasing with increases in altitude [42]. However, the relationship between leaf size and environmental factors is not fixed, and may vary in different regions or different species [41]. Leaf area and specific leaf area (SLA) are related to plant photosynthesis and primary productivity, which is very important for understanding plant responses to climate change [43]; while leaf nutrient content affects nutrient cycling in forests [37].…”

Population Variability of Almond-Leaved Willow (Salix triandra L.) Based on the Leaf Morphometry: Isolation by Distance and Environment Explain Phenotypic Diversity

“…While the variability is most often related to functions of photosynthesis [2,6,7] and drought response [8][9][10], leaves have been shown to display variability as a result of numerous climatic influences, including temperature [11][12][13], precipitation [14][15][16] and light conditions [17][18][19][20]. Additionally, the influence of latitude [21,22] and altitude gradient [3] on variations in leaf morphology has been proven. The underlying mechanisms of adaptation are both anatomical and physiological.…”