Holocene climate fluctuations and vegetation dynamics in northeastern Taiwan reconstructed through pollen analysis from Shenmihu Lake

Shenmihu is a lake in northeastern Taiwan at an elevation of approximately 1100 meters, marking the boundary between broadleaf and coniferous forests. Pasania currently dominates the surrounding vegetation. This study aims to reconstruct environmental changes in the Shenmihu catchment over the past 10000 years during the Holocene through pollen analysis. Because plants produce pollen, which is often preserved in sediments, pollen analysis is a crucial proxy for investigating how vegetation distributions have responded to shifts in climate and human agricultural activities.

The results show that, although Pasania generally dominates the region, Alnus populations increased between 4900 and 900 cal BP, becoming the main species from 3500 to 1400 cal BP. This shift was likely driven by cooler climates and significant disturbances, such as typhoons that triggered landslides. These findings underscore the importance of climate fluctuations and extreme weather events in shaping local vegetation over time. Additionally, human agricultural activities likely played a role in altering plant communities, illustrating the complex interplay between natural and anthropogenic factors.

To understand broader regional trends, pollen data from Shenmihu were compared with records from Cuifeng Lake and Retreat Lake, both located in northeastern Taiwan. Through this comparative approach, the study aims to document past climate fluctuations in northeastern Taiwan and assess how vegetation distribution evolved throughout the Holocene.