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.
During the summer of 2012 and 2013, a total of 287 R. soongarica individuals were sampled in situ from 30 wild populations. These sampling sites covered the whole range of R.soongarica in northwest China. In each population, four to ten healthy shrubs that had not been eaten by animals were randomly selected.
A total of 17 populations spaced at least 100 km apart were included in the common garden trial of R. soongarica (seven populations in Gansu, five in Ningxia, four in Inner Mongolia and one in Sinkiang; Table 1). In each population, the seeds were harvested from 20 different individuals 30 m apart and then planted at the Gaolan Station of the Agricultural and Ecological Experiment, Northwest Institute of Eco-Environment and Resources, CAS (36.2368 °N, 103.7981 °E, 1,800 m above sea level).In the spring of 2012, three seeds from each plant were first sown into a 10 cm diameter pot that contained a 1:1 mixture of loess and nutrient soil,The common garden plants were sampled in July 2017, according to the method described above.
The Kolmogorov–Smirnov normality test was performed on all leaf morphological data and environmental data. Leaf length, leaf width, and L/W of some natural and common garden populations were abnormally distributed. Therefore, Kruskal–Wallis ANOVA tests were conducted to detect the differences in leaf characteristics among natural populations and among cultivated populations.
The data quality is good.
| # | number | name | type |
| 1 | 31770416 | National Natural Science Foundation of China | |
| 2 | 31901079 | National Natural Science Foundation of China |
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CSTR:11738.11.NCDC.ZENODO.DB3955.2023
10.5061/dryad.dv41ns1vr