Response and adaptation of Quercus glauca leaf functional traits to different altitudinal gradients

Plant functional traits are a series of attributes of plants, reflecting the adaptive strategies of plants to environmental changes. It can not only respond to changes in the external environment, but also affect the function of forest ecosystems, elevation as a key comprehensive environmental factor, the temperature difference between different elevations provides innate conditions for studying how plants adapt to low temperature environment. As a representative plant in subtropical evergreen broad-leaved forest, there are few studies on leaf functional traits of Quercus glauca, and the ecological strategies adopted by Quercus glauca to cope with the high altitude and low temperature environment are very limited. To study the changes of leaf functional traits of Quercus glauca at different altitude gradients is helpful to understand its survival and tradeoff strategies in response to environmental changes, and to provide references for understanding the adaptation mechanism of subtropical evergreen deciduous broad-leaved mixed forest vegetation to environmental and climate change.

In this paper, the leaf functional traits of Quercus glauca in different elevations (Ⅰ, Ⅱ, Ⅲ) of Hubei Mulinzi national nature reserve were measured to reveal the variation rules among different elevations, explore the differences and correlations among the functional traits, and explore the adaptive strategies to cope with the harsh environment in the high altitude area.

The variation of 6 functional traits of the leaves of Quercus glauca was 9.81%-25.17%, and the variation coefficient of dry matter content in the middle lobe was the smallest, and the leaf area was the largest. The leaf area and specific leaf area of Quercus glauca decreased with the increase of altitude. Leaf thickness, leaf dry matter content and leaf N content increased with the increase of altitude. With the increase of altitude, leaf P content increased first and then decreased, all 6 functional traits were correlated with each other, the survival strategy of Quercus glauca gradually changed from “fast return” to “slow return”.

Among different altitude gradients, there were differences in the functional traits of the leaves of Quercus glauca, which adapted to the harsh environment in the high altitude area through the interaction and restriction of the functional traits.