Forest health estimation in Sholayar Reserve Forest, Kerala using AVIRIS-NG hyperspectral data

The present study deals with analyzing forest health, its parameters, and suitability of hyperspectral data for vegetation health-related studies. Sholayar reserve forest in Kerala has a huge reserve of equatorial moist evergreen forest and demands preservation in every respect. Due to increased human interferences coupled with possible climate change, its health is undergoing a stage of deterioration. Stress levels in the canopy were assessed using a number of stress-related pigments. Detailed study of vegetation response to canopy leaf pigments have been carried out in the study. Airborne Visible Infrared Imaging Spectrometer Next Generation (AVIRIS-NG) data provides immense possibilities to study a number of stress-related pigments like anthocyanin, carotenoid, lignin, chlorophyll-a, b etc. Dominant species in these forests are Holigarna arnottiana , Grevillea robusta , Grewia tiliifolia , Syzygium cumini , Alstonia Scholaris , Cinnamomum verum , Artocarpus heterophyllus , Bischofia javanica , Mangifera indica , Bombax ceiba , Anogeissus latifolia , Terminalia paniculata etc. Apart from luscious natural vegetation, plantation of teak ( Tectona Grandis ), rubber ( Hevea brasiliensis ), tea ( Camellia sinensis ), Coffee ( Coffee Arabica ), Palm-Oil tree ( Elaeis guineensis ) etc. also exists. Field data pertaining to one of the selected pigments was correlated with remotely sensed pigment estimates. Correlation of field measured chlorophyll concentration and EVI showed R 2 = 0.421. Similarly, the anthocyanin index showed a correlation of R 2 = 0.319. In the Sholayar Reserve Forest (493.0 km 2 ) an area of 141.0 km 2 was found to be in a healthy state. Whereas about 218.0 km 2 of area exhibit moderately healthy condition and 77.0 km 2 area was in the least healthy state.