[ACG54-P07] The long-term observation of PRI and LUE and phenology changes in a temperate Japanese cypress forest at Kiryu Japan.
Keywords:Japanese cypress, photochemical reflectance index (PRI), photosynthetic light use efficiency(LUE), phenological analysis
We made use of the digital camera to monitor the canopy phenology changes. The digital camera takes photos in 3 hours interval, and we extracted the RGB channels of image data to calculate the greenness indices.
Combining with the vegetation indices data and the phenology changes data can allow us to figure out the Japanese cypress forest phenology changes patterns and deeply knowledgeable about the relationships between PRI and LUE.
Our findings demonstrated that LUE has a good relationship with the PRI. Correlation coefficient calculated results shows that LUE and PRI significantly associated in 297 fine days (R>0.75). During the monitoring period, apparent seasonal and diurnal change of the PRI observed at temperate Japanese cypress forest. Furthermore, the PRI was observed that reaches the peak in September and the valley in February. We also found out distinct phenology changes patterns with the phenological analysis results. The greenness index showed similar seasonal changes with that of PRI. When the redness index reaches the peak, the PRI reaches the valley. It suggested that leaf redding phenomena causes the decline of PRI and LUE.