17:15 〜 18:45
[HQR04-P06] Late Holocene vegetation and climate changes in the southern Taiwan
キーワード：Pollen, Holocene, Little Ice Age, Taiwan
Pollen analysis in sediment is a robust proxy to reconstruct the historical evolution of natural vegetation distribution in an area, allowing inferences about past climate changes and documenting the impact of human activities on the region. Stable isotope analysis, by examining carbon isotopic compositions (δ13C) in sediments, serves as an indicator of changes in the ratio of C3 to C4 plants, reflecting past climate conditions. Changes in Total Organic Carbon (TOC) signify alterations in the preservation state of organic matter inputs, while the C/N ratio indicates variations in the source of organic material, reflecting changes in the composition of natural vegetation in the region.
In this study a 200 cm sediments was extracted from a wetland at mid-low elevation (1468.8 meters above sea level) in Guzailun Mountain, Pingtung, Taiwan. Pollen composition and δ13C of organic matter along with its TOC and total nitrogen (TN) contents were measured to reconstruct the paleoclimate changes and natural disasters in the southern mountainous region of Taiwan. In the current study, high C/N ratios along with relatively lower δ13C showed higher runoff condition and contribution of C3 plants in the studied region, indicating warm period during 350 to 900 AD, which were attributed to the Pre-Medieval Warm Period (PreMWP). Furthermore, a slight increase in C/N was noticed along with a rise in δ13C during 900-1300 AD, which indicates stronger runoff conditions and a slight increase in contribution of C4 plants in the region. This time frame is attributed to the Medieval Warm Period (MWP). A slight decrease in C/N ratios were noticed, however, δ13C did not showed any significant changes during 1300-1800 AD. It possibly indicated the lower runoff conditions in the region, suggesting drier climate conditions and attributed to Little Ice Age (LIA).
In this study a 200 cm sediments was extracted from a wetland at mid-low elevation (1468.8 meters above sea level) in Guzailun Mountain, Pingtung, Taiwan. Pollen composition and δ13C of organic matter along with its TOC and total nitrogen (TN) contents were measured to reconstruct the paleoclimate changes and natural disasters in the southern mountainous region of Taiwan. In the current study, high C/N ratios along with relatively lower δ13C showed higher runoff condition and contribution of C3 plants in the studied region, indicating warm period during 350 to 900 AD, which were attributed to the Pre-Medieval Warm Period (PreMWP). Furthermore, a slight increase in C/N was noticed along with a rise in δ13C during 900-1300 AD, which indicates stronger runoff conditions and a slight increase in contribution of C4 plants in the region. This time frame is attributed to the Medieval Warm Period (MWP). A slight decrease in C/N ratios were noticed, however, δ13C did not showed any significant changes during 1300-1800 AD. It possibly indicated the lower runoff conditions in the region, suggesting drier climate conditions and attributed to Little Ice Age (LIA).