Phytolith records from 15 continuously growing Bambusa emeiensis leaves and its climatic significance

In order to explore the effect of silica accumulation on the modern bamboo phytoliths, 15 consecutive bamboo leaves of Bambusa emeiensis were employed for observation of different leaf-age phytolith types and their link to the climatic environment. Phytoliths for anatomical terms are divided into six groups: short cells, long cells, bulliform cells, hair cells, silicified tissues and stomata. Short cells make a great contribution to the total percentage of phytoliths counted under the microscope. The effect of silica accumulation on the phytolith morphology of Bambusa emeiensis leaf is limited, and it can not prevent the phytolith records of the climatic information of the growth environment of Bambusa emeiensis. Three phytolith assemblage zones respond very clearly to the three major climatic stages varying from warm-humid to warm-dry and cool-dry conditions. Correlation analysis among phytolith indices and climatic factors at different time levels indicate that the warmth index (Iw) has a highly significant correlation with the 10-day mean temperature, and aridity index (S/F) has a significant correlation with 10-day total evaporation, respectively, which is in good accordance with the average maturity time (10 days or so) of a new leaf. This study reveal that the leaf phytoliths of Bambusa emeiensis can sensitively respond to the living temperature and evaporation corresponding to the growth and maturity of a new leaf. Our results will provide valuable evidence for the climatic significance of modern plant phytoliths and shed the insight into the plant ecophysiological response to the global change in the future.