The altitudinal zonation have treeline in the lower reaches and seasonal snowline in the higher reaches comprising of Ganging Mouling peak (3064 MSL), Marang Mouling peak (2940 MSL) and Sibum Mouling peak (2634 MSL).
Upper reaches with high rainfall and moderate temperatures
Pine and conifer dominated forests at mid-elevations
Deciduous and evergreen broadleaf species
Lower reaches with dense evergreen vegetation
Transition zone between tropical and temperate forests
The altitudinal zonation has treeline in the lower reaches and seasonal snowline in the higher reaches comprising of following peaks: