Variation in leaf anatomical traits of Betula albosinensis at different altitudes reflects the adaptive strategy to environmental changes

Abstract

The ability of plants to adapt to environmental variability and self-regulate in complex habitats often reflected in leaf anatomical changes. In an assessment of 19 characteristics of Betula albosinensis leaves, samples were taken from trees grown along an altitudinal gradient on the eastern edge of the Qinghai-Tibet Plateau and distributed at three altitudes: 2434 m, 2824 m, and 3060 m. Anatomical characteristics of the leaves' blade, mesophyll, and midrib were studied using paraffin slice technology. We found that altitudes and changes in altitude affected the leaf anatomy. As altitude increased, the blade and the mesophyll became thinner, and the transport tissues of the midrib became relatively underdeveloped. However, intra-altitudinal variation was the main source of phenotypic variance. Pearson correlation and principal component analysis revealed that each trait had different ecological dimensions, and that there were trade-offs and covariance relationships between traits. In summary, to adapt to the local altitudinal conditions, Betula albosinensis may exhibit multiple responses, such as reducing investment in leaves, which can boost short-term growth rates, and the "quick investment and return" strategy. Our findings are useful in understanding anatomical adaptations and their trade-offs to environmental variation.

Leaf flavonoids in Chinese sea-buckthorn (Hippophae rhamnoides subsp. sinensis Rousi) and their response to environmental gradients across northern China

“…Habitat is the ecological environment that a species or a group of species depends upon, which may be characterized by such abiotic factors as altitude, temperature, and precipitation [10,11]. Secondary substances have evolved via long-term interactions between plants and their environment, and these products serve as the material basis for environmental adaptation, which in turn generates a unique diversity of chemical [12].…”