Understanding the changes in below-ground bud bank density and composition along a climatic gradient is essential for the exploration of species distribution pattern and vegetation composition in response to climatic changes. Nevertheless, investigations on bud banks along climatic gradients are still scarce. The below-ground bud bank is expected to be reduced in size in arid conditions, and costly, bud-bearing organs with long spacers would be replaced by more compact forms with buds that are better protected than those found in moist conditions.
Qian et al. tested how total bud density and composition change along a 2500 km climatic gradient (aridity, precipitation and temperature) in the temperate steppe of northern China. They find that belowground bud bank density decreases towards the dry, hot end of the climatic gradient. Based on the bud banks’ distribution pattern, bulb buds and tiller buds of tussock grasses are shown to be more resistant to environmental stress than rhizome buds.
This paper is part of the Special Issue on Morphology and Adaptation. It is FREE access for a limited period to the end of January 2018. It will then be free access from November 2018.