Ecological Indicators (Dec 2021)
Temperature, not precipitation, drives the morphological traits of Didymodon rigidulus in Tibet
Abstract
Plant traits reflect the response and adaptation of plants to environmental changes and play important roles in the prediction of the effects of different environmental conditions on plants and plant-mediated processes. However, few studies have focused on the traits of nonvascular plants, such as bryophytes, although such plants are important participants in the primary productivity and biogeochemistry in harsh environments. In this study, the adaptive morphological traits and their interactions in the moss species that adapt to harsh and acute changeable environment were determined. Environmental factors that drive the changes in these traits were also evaluated. A total of 43 specimens of Didymodon rigidulus were collected from 38 sampling sites in arid and semi-arid regions in Tibet. Twelve morphological traits were investigated by microscope measurement, and then their interrelations and relations to environmental variables were quantified by employing Spearman’s correlation analysis, hierarchical partitioning analysis, and partial least squares path modeling. Results showed that along with the environmental gradient, the plant height, leaves, and cells of D. rigidulus had changed significantly, and these parameters were largely interpretable in functional and adaptive terms. The lower the mean annual temperature (MAT) was, the thicker was the surface cell wall and the wider was the cell cavity of D. rigidulus. The higher potential evapotranspiration (PET) was, the thicker was the surface cell wall but the smaller were the leaves. MAT and PET were the main driving forces for the development of such traits of D. rigidulus. These results provide important insight into the adaptive syndrome of nonvascular plants associated with stress tolerance in the varied and harsh environment in Tibet. This study indicated the importance of considering the effects of climate change, especially the warming temperature on species adaption and community assemblage.
