This type of forest is intermediate between the Tropical Evergreen and Moist Deciduous and generally considered as a transitional stage from evergreen to moist deciduous. It is found between 600 to 800 m elevation and in some areas descends up to 500 m. These may be mainly due to the change in environment or human interference or both. The West Coast Semi-evergreen Forest accordingly forms a close high forest, the dominant trees sometimes running to big dimensions but is usually inferior to that of the Tropical Evergreen.

This type includes both the evergreen and deciduous trees, the former predominating in intimate mixture but with a definite tendency to gregariousness. The bigger trees continue to be frequent in this forest and occur in both evergreen deciduous trees. The bark tends to be thick and rough. The density of the canopy in this type is less than that of the evergreens, but the canopy is well developed with stratification. Climbers are seen in abundance and the undergrowth is more of coppice. The epiphytes usually met with are chiefly ferns and orchids. This type occurs throughout the moist parts of the tropics, where the moisture conditions are adequate for its development but at the same time inadequate for an evergreen climax. This type of Forest is met with in the lower reaches of Karinganni and Pulikkan-Chudupulan blocks of this sanctuary. The floristic composition is given below.