Three major types of plant communities are found within the park: – Grasslands, Shrub lands and Shola Forests. The terrain above 2000m is covered primarily by Grasslands. However, there are numerous small patches of forests in hollows and gullies in these areas.
The deeper valleys are extensively forested. Shrub Lands predominate along the bases of the cliffs and interspersed in rocky slab areas. Around 60% of the area is covered by Grasslands, about 25% by Shola Forests, about 8.45% by Southern Sub Tropical Hill Forest and 7.5% constitute the Shrubs (Menon, 1997).
The study on land cover in Eravikulam National Park reveals that the Grasslands constitutes 60 % of the land cover, Shola Forests constitute about 20 % of the land area and the remaining area is occupied by Southern Tropical Hill Forests, Scrubs and Rocky cliffs ( Balakrishnan M, Surendrananthan Asari P.K, 2002).
The reason for distribution of the Forests and Grasslands side by side, still remains a riddle. The ecological explanations fall into two categories: (1) Those which describe the Shola-Grassland ecosystem as a poly climax and (2) Those which maintain that the Shola Forests is a true climax and that the Grassland is a sub climax maintained by human disturbance, fire and grazing in particular.
The Biogeographic Classification
Biogeographically, the park falls in the following categories:
- Biogeographic Zone: Paleo Tropical, Indo-Malayan Realm, Western Ghats
- Biotic Province: 5B Western Ghat Mountain
- Bioma: Mountain Forest-Grassland