Abstract
This study proposes a new method to detect changes of altitudinal distribution limit of a plant species based on the stomatal analysis of fossilized leaves. We use the Holocene fossil leaves of Fagus crenata (Japanese beech), a dominant deciduous tree in the cool temperate zone, from different horizons in a peat bog in Mt. Kurikoma, north Japan. Results of palaeo‐CO2 concentration reconstructed from the stomatal analysis indicate palaeo‐CO2 fluctuation between 317 and 352 ppmv during the Middle–Late Holocene, which was more variable and higher than Greenland and Antarctic ice‐core records. This result is possibly influenced by the oceanic CO2 uptake, which increased with the strengthening of the Tsushima Warm Current during the Middle Holocene. The stomatal index (SI) variation range of fossil Fagus crenata leaves in the Middle Holocene was higher than that of the modern population at a given altitude, indicating transportation of leaves from an altitude higher than the site of fossil deposition. A decreasing trend of the SI variation range between 5000 and 2500 cal. a BP can possibly be attributed to the downward shift of the upper distribution limit of Fagus crenata from an altitude higher than or similar to the present limit to the area surrounding the fossil deposition site. This downward shift of the upper distribution limit of Fagus crenata was simultaneous with temperature and humidity decreases and correlated with the decreasing East Asian Summer Monsoon intensity and a cooling event around 4000 cal. a BP.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.