[M-AG33] Satellite Land Physical Processes Monitoring at Medium/High/Very High Resolution

[MAG33-04] Monitoring General Flowering in Sarawak, Borneo with High Resolution Remote Sensing

*Tomoaki Miura^1,2、Yuji Tokumoto^3,4,5、Nagai Shin² (1.University of Hawaii at Manoa、2.Japan Agency for Marine-Earth Science and Technology、3.University of Miyazaki、4.University of Zurich、5.Yokohama City University)

キーワード：commercial remote sensing, phenology, general flowering

General flowering (GF) is a unique biological phenomenon of the mixed lowland dipterocarp forest in Southeast Asia. GF occurs at irregular intervals often after one to 10 years of sterility in which a large number of tree species from different families flower synchronously for a few weeks to a few months. Characterizing the spatial extent and temporal dynamics of GF is essential to improve our understanding of the potential climate change impact on this rainforest. We investigated how well general flowering could be characterized with newly-available high temporal (daily) and high spatial (3–4 m) resolution remote sensing by the PlanetScope commercial satellite constellation. Our study was focused on the 2019 GF event known to have occurred at Lambir Hills National Park, Sarawak, Malaysia. PlanetScope successfully acquired 13 clear-sky or minimally cloud-contaminated scenes over the park for a study period of 1 January – 31 August 2019. In situ phenology observations verified that the PlanetScope images detected the flowering tree crowns that turned into white or orange, but not yellow. This multi-temporal image dataset differentiated the multiple flowering peaks associated with different species. Overall, the analysis results indicated that the 2019 GF event was a whole-park phenomenon with the flowering peak in May. This study suggests the possibility of regional-scale characterization of species-level phenology in the species-rich dipterocarp forest.