Geographical differences of leaf traits of the endangered plant Litsea coreana Levl. var. sinensis and its relationship with climate

Seventeen morphological and anatomical characteristics of the leaves were selected from five natural populations to explore the variation in leaf traits of Litsea coreana var. sinensis and the effects of geographical environment on these variations. Nested analysis of variance, multiple comparisons, principal component analysis (PCA), and correlation analysis were conducted to explore the variations within and between populations and their correlation with geographical and climatic factors. Significant differences in the 17 leaf traits were observed within and among populations. On average, the relative contribution of within population variation to total variation was 24.8%, which was lower than among population variation (54.6%). The average differentiation coefficient of the traits was 65.8%, and the average coefficient of variation 11.8%, ranging from 6.7% for main vein thickness to 21.4% for petiole length. The PCA results showed that morphological characteristics were divided into two categories, and the level of variation was greater than that of leaf anatomy. Most of the leaf traits were significantly correlated with geography and climate and showed a gradual variation with longitude, latitude, and altitude. In areas with high temperatures, less rainfall, and strong seasonal rainfall, the leaves are larger, longer and thicker. This study shows that variations in leaf traits of L. coreana var. sinensis mainly come from variations among populations. The level of trait differentiation among populations is high and the level of variation within populations low. These findings help further understand leaf morphological characteristics of this species and can provide a valuable reference for the protection and sustainable utilization of this natural resource.

Automated summary

Seventeen morphological and anatomical characteristics of the leaves of Litsea coreana var. sinensis were studied to investigate the variation in leaf traits and the influence of geographical environment. The results showed significant differences in leaf traits within and among populations. Among population variation accounted for a higher proportion of total variation than within population variation. The variation in leaf traits was mainly influenced by geography and climate factors, showing a gradual change with longitude, latitude, and altitude. These findings provide important insights for the conservation and sustainable use of this species.