Detecting Suaeda salsa L. chlorophyll fluorescence response to salinity stress by using hyperspectral reflectance

Measurements of chlorophyll fluorescence and hyperspectral reflectance were used to detect salinity stress in Suaeda salsa L., beach of Dongtai, Jiangsu Province, China. Three experimental sites were used in our study, which belong to low salinity, middle salinity and high salinity. The results showed that leaf chlorophyll fluorescence changed along salinity gradient. To select the sensitive hyperspectral ranges of leaf chlorophyll fluorescence, the correlationship between leaf chlorophyll fluorescence and hyperspectral reflectance was regressed and analyzed. Statistical results indicated that the 680 and 935 nm were the most sensitive hyperspectral bands for estimating leaf chlorophyll fluorescence. Then, 11 relative hyperspectral indices were selected based on the sensitive bands and previous literature. (R (680) - R (935))/(R (680) + R (935)) and R (680)/R (935) have higher correlationship coefficient (R) and lower root mean square error, may be used for detecting chlorophyll fluorescence, such as F (o), F (m), F (v)/F (m), qP, and I broken vertical bar PSII, while NPQ may be detected by (R (780) - R (710))/(R (780) - R (680)). These results suggest that chlorophyll fluorescence of halophyte response to salinity stress could be identified by remote sensing.