[M-IS12] Mountain Science

[MIS12-P09] Long-Term Vegetation Phenology Changes in Cool-Temperate Deciduous Forests of Japan Revealed by Two Decades of Time-Lapse Photography

*Taiga Sasagawa¹, Hiroyuki Muraoka², Hibiki M Noda³, Tomoko Kawaguchi Akitsu⁴, Toshiyuki Kobayashi⁵, Kenlo Nasahara⁵ (1.Chiba University, 2.Gifu University, 3.National Institute for Environmental Studies, 4.Japan Aerospace Exploration Agency, 5.University of Tsukuba)

Keywords:Vegetation Phenology, Time-lapse Camera, Long-term Observation, Phenological Eyes Network (PEN)

Vegetation phenology serves as a key indicator for assessing the impacts of climate change on ecosystems and plays a crucial role in regulating biogeochemical cycles. Continuous monitoring through in-situ time-lapse cameras provides a reliable method for detecting phenological changes with high accuracy. In recent years, the use of in-situ time-lapse camera systems for phenological studies has expanded among research communities. However, most existing datasets span only about a decade, limiting the ability to analyze long-term trends. Extended observation periods are essential for a more comprehensive understanding of climate-driven phenological changes. One of the longest-running phenological monitoring networks is the Phenological Eyes Network (PEN), which offers valuable long-term records. In this study, we analyzed over two decades of time-lapse images from PEN to investigate vegetation phenology in a cool-temperate deciduous broadleaf forest in Japan. By examining time-series images of both the canopy and forest floor, we explored the relationships between climate variables and individual tree phenology within the observation area. Our findings reveal phenological shifts in specific individuals, such as an earlier onset of spring phenology. Furthermore, we introduce a newly developed in-situ time-lapse camera system based on a single-board computer designed to enhance long-term phenological monitoring efforts.