Cuticular waxes in alpine meadow plants: climate effect inferred from latitude gradient in Qinghai-Tibetan Plateau.

Yanjun Guo,Na Guo,Jianhua Gao,Yuji He

doi:10.1002/ece3.1677

Abstract

Alpine meadow ecosystems are susceptible to climate changes. Still, climate impact on cuticular wax in alpine meadow plants is poorly understood. Assessing the variations of cuticular wax in alpine meadow plants across different latitudes might be useful for predicting how they may respond to climate change. We studied nine alpine meadows in a climate gradient in the east side of Qinghai-Tibetan Plateau, with mean annual temperature ranging from -7.7 to 3.2°C. In total, 42 plant species were analyzed for cuticular wax, averaged 16 plant species in each meadow. Only four plant species could be observed in all sampling meadows, including Kobresia humilis,Potentilla nivea,Anaphalis lacteal, and Leontopodium nanum. The amounts of wax compositions and total cuticular wax in the four plant species varied among sampling meadows, but no significant correlation could be observed between them and temperature, precipitation, and aridity index based on plant species level. To analyze the variations of cuticular wax on community level, we averaged the amounts of n-alkanes, aliphatic acids, primary alcohols, and total cuticular wax across all investigated plant species in each sampling site. The mean annual temperature, mean temperature in July, and aridity index were significantly correlated with the averaged amounts of wax compositions and total cuticular wax. The average chain length of n-alkanes in both plant and soil linearly increased with increased temperature, whereas reduced with increased aridity index. No significant correlation could be observed between mean annual precipitation and mean precipitation from June to August and the cuticular wax amounts and average chain length. Our results suggest that the survival of some alpine plants in specific environments might be depended on their abilities in adjusting wax deposition on plant leaves, and the alpine meadow plants as a whole respond to climate change, benefiting the stability of alpine meadow ecosystem.

Highlights

Alpine meadows are widely distributed in Qinghai-Tibetan Plateau, and they are considered to be sensitive to climate change
We addressed the following two aspects: (1) How does cuticular wax in alpine meadow plants respond to climate change on plant species level? (2) Can n-alkane distribution in soils and plant community reflect the responses of alpine meadow plants to climate change?
Alpine meadows were sampled according to latitude gradients from N37.43 to N31.12, the values of the environmental factors of the sampling meadows depended upon both latitude and altitude (Table 1)

Summary

Introduction

Alpine meadows are widely distributed in Qinghai-Tibetan Plateau, and they are considered to be sensitive to climate change. As the outmost surface of plant, cuticular wax directly contacts with the environment and shows great sensitivity to climate change (Shepherd and Griffiths 2006). Cuticular wax plays pivotal physiological and ecological roles in the interactions between plants and their abiotic and biotic environments (Bouzoubaa et al 2006). It inhibits the loss of water from leaf surface, limits water transportation into leaf, increases disease resistance, provides ultraviolet light protection to leaf tissue, and protects plants from air pollution (Pannell and Fields 2014). Assessing the variations of cuticular wax in alpine plant species across different latitudes might be useful for predicting how they may respond to changing climate

Methods

Results

Discussion

Conclusion