Response of leaf morphometric traits of Quercus species to climate in the temperate zone of the North-South Transect of Eastern China

Abstract

Aims Plant leaf morphological traits can effectively reflect changes of plant living environments and affect the behaviors and function of plants. Our objective was to reveal the response of leaf morphometric traits of Quercus species to climate in the temperate zone of the North-South Transect of Eastern China (NSTEC). Methods We obtained leaf morphometric information by measuring plants in herbariums. We used mathematical methods of correlation analysis and standardized major axis to investigate relationships between leaf morphology and climate factors, as well as correlations among leaf morphological traits. Important findings With changing climate conditions in the temperate zone of NSTEC, leaf morphological traits of Quercus species changed significantly. Leaf area of Quercus species increased with decreased annual tem- perature and increased annual sunlight, which helps leaves to absorb more light radiation and reduce the loss of heat. The degree of leaf division can not only decrease heat dissipation from leaves, but can also enhance the fluctuation of sap flow to improve the physiological activities of leaves. Vein density increased with increased temperature and light intensity, improving the water transportation capacity, and increased with increased precipi- tation, improving the supporting ability of leaves. In addition, in order to adapt to the changed climate conditions, Quercus species built a combination of leaf morphological traits, with increased leaf area, petiole length and de- gree of leaf division, while vein density decreased. Petiole length and vein density also increased with the leaves tending toward an elongated shape.