Effect of elevation changes on bud bank characteristics of alpine meadow
on the Zoige Plateau
Abstract
Overgrazing and low temperature prevent plants sexual reproduction, and
belowground bud banks play an important role in perennial plant
communities. The purpose of the study is to explore the bud bank
characteristics of alpine meadow with elevation changes. We studied the
bud bank distribution, size and composition of alpine meadow at 3450 to
3950 m elevation using a unit soil excavation method on the eastern
Zoige Plateau. Our results showed that the bud density at the low
elevation was higher than that at the high elevation as a whole. The
belowground bud bank comprised tiller, long and short rhizome buds. Bud
bank composition varied with elevation, tiller buds were the dominant
ones, accounted for 35.47% to 65.28% of total buds. In general, tiller
bud proportion increased with increasing elevation. Buds were mostly
concentrated in 0-10 cm sod layer, the density was between 963 and 1793
No./m3, accounted for 93.41% to 100% of total buds, and there were
fewer buds distributed in 10-30 cm sod layer. The aboveground biomass of
plants increased gradually with increasing elevation, and belowground
biomass decreased gradually as a whole. Redundancy analysis (RDA) showed
that sod layer properties affected bud bank composition. Total
phosphorus, total nitrogen, available phosphorus content was the most
important factor explaining and contributing to the variation of bud
density. This study suggested that alpine meadow plants maintain a
certain scale of bud bank. Environment affects the structure and
distribution of plant bud bank on the Zoige Plateau, and plants
constantly alter the bud bank and adjust propagation strategy to cope
with environmental changes and maintain the community stability.