Selected Site: Bekanbeushi Moor, Northern Japan
Proxies
- Celluloseδ18O values of Sphagnum moss and vascular plants: This proxy reconstructs historical humidity (or environmental conditions) by going back beyond the current time and, generally, serves as an indicator.
- Porewater δ18O and δD: The isotopic signatures of water in the pores reveal the dynamics in the hydrological systems and the sources of water that are crucial for the peatland ecosystem function (Sakurai et al., 2021).
Research Objectives
The main aim was to reconstruct the paleoclimatic variability of northern Japan over the past 20,000 years by applying δ18O of Sphagnum moss and vascular plants in addition to δ18O and δD of pore water in addition to comprehending the humidity fluctuations and Northern Summer Western winds (Sakurai et al., 2021).
New Scientific Observations
The research proved that Sphagnum moss and vascular plants had different δ18O values because they got their water from various sources, and both had different environmental factors that affected their lives (Jones et al., 2019; Nicholes et al., 2010). The findings enable us to identify the connections between seasonal humidity variations and atmospheric dynamics, aiding in our comprehension of how summer rainfall patterns have shifted from 20,000 years ago to the present.. This information enables us to restore and identify the area’s climate conditions and estimate possible fluctuations of plant life in the past 20,000 years.
Global Patterns
δ18O of cellulose and the pore watervalues normally act as an indicator of climate change at a global scale. In northern Japan, the drifting of westerly winds and regional humidity diversities coincide with the global climatic patterns reflecting how atmospheric circulation has changed in the Holocene (Li et al., 2017).
Phenomenon of Interest and Research Plan
Bekanbeushi Moor could be a fascinating manifestation of the past association between local humidity patterns and climate variability. The research plan will involve performing a high-resolution analysis of cellulose δ18O values from a 20,000-year-old peat core of Sphagnum moss in Bekanbeushi Moor. Additionally, by analyzing pore water δ18O and δD, we can elucidate the hydrological dynamics of peatland and the water sources affecting the ecosystem.
- Temporal Resolution: Samples will be tested for 100 – 200 years or less to capture the rapid variations in humidity.
- Spatial Resolution: A detailed and informative introduction to the core field related to the Holocene era will be developed, outlining the past climate variability in northern Japan.
Advantage over Alternative
This approach will utilize the parallel trace of two proxies (cellulose δ18O values and pore water isotopes) to create a minimally invasive diagnosis system. This system is expected to significantly increase the accuracy of past humidity levels and climate variability assessment at the site of Bekanbeushi Moor. The isotopic composition is anticipated to reveal significant changes in flora response to paleoclimatic regimes via cellulose δ18O data. In contrast, pore water δ18O will provide insights into the hydrological processes, thus offering a multi-dimensional perspective.
Required Equipment
– A coring sampler for the preparation of the sample
– An isotopic mass spectrometer
- 0.22-μm filter.
- Heat source
Expected Results
The study aims to reveal unexpected cellulose δ18O value anomalies in Sphagnum moss, indicating past humidity changes and climate variability in northern Japan. Additionally, the isotopic ratios in the water content should help us understand changes in the underwater environment and groundwater sources.
Bibliography
Jones, M. C., Anderson, L., Keller, K., Nash, B., Littell, V., Wooller, M., & Jolley, C. A. (2019). An assessment of plant species differences on cellulose oxygen isotopes from two Kenai Peninsula, Alaska peatlands: Implications for hydroclimatic reconstructions. Frontiers of Earth Science, 7, 25. https://doi.org/10.3389/feart.2019.00025
Li, X., Sugimoto, A., & Ueta, A. (2017). Spatial and temporal variations of stable isotopes in precipitation in midlatitude coastal regions. Hydrological Processes, 31, 3029–3044. https://doi.org/10.1002/hyp.11222
Nichols, J., Booth, R. K., Jackson, S. T., Pendall, E. G., & Huang, Y. (2010). Differential hydrogen isotopic ratios of Sphagnum and vascular plant biomarkers in ombrotrophic peatlands as a quantitative proxy for precipitation—Evaporation balance. Geochimica et Cosmochimica Acta, 74, 1407–1416. https://doi.org/10.1016/j.gca.2009.11.012
Sakurai, H., Yamamoto, M., Seki, O., Omori, T., & Sato, T. (2021). Cellulose oxygen isotopes of Sphagnum and vascular plants in a peat core reveal climate change in northern Japan over the past 2,000 years. Geochemistry, Geophysics, Geosystems, 22, e2020GC009597. https://doi. org/10.1029/2020GC009597
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