Tropical Evergreen Forests are characterized by dense and multi-layered canopies where trees remain green throughout the year due to consistent rainfall and warm temperatures. These forests are primarily found in regions that receive over 200 cm of annual rainfall, with short or no dry seasons.
Characteristics:
- Climate: High rainfall (more than 200 cm annually) and consistently warm temperatures (25-30°C).
- Canopy: Very dense, multi-layered canopy with trees often reaching heights of over 60 meters.
- Biodiversity: Extremely high biodiversity, with numerous species of trees, shrubs, climbers, epiphytes, and a rich variety of wildlife.
- Soil: The soil is generally rich in organic matter but can be acidic and low in nutrients due to heavy rainfall leaching away soluble minerals.
Flora:
- Dominant tree species include Mahogany, Ebony, Rosewood, and Ironwood.
- Common epiphytes (plants growing on other plants) include orchids and ferns.
- Understory vegetation consists of smaller trees, shrubs, and herbaceous plants.
Fauna:
- These forests are home to a wide variety of wildlife, including tigers, leopards, elephants, deer, and various primates.
- Bird species are abundant, with species like hornbills, peafowls, and eagles.
- Reptiles, amphibians, and a rich diversity of insects also thrive in these habitats.
Example:
- Western Ghats: Stretching along the west coast of India, the Western Ghats host extensive tropical evergreen forests. Notable areas include the Silent Valley in Kerala and the Agumbe region in Karnataka.
Significance:
- These forests play a crucial role in carbon sequestration, maintaining regional hydrology, and harboring biodiversity hotspots.
- They also support local communities through non-timber forest products like fruits, nuts, and medicinal plants.
Tropical Semi-Evergreen Forests in India
Tropical Semi-Evergreen Forests are a transitional type between evergreen and deciduous forests. They receive slightly less rainfall than evergreen forests (around 150-200 cm annually) and have a marked but short dry season.
Characteristics:
- Climate: Moderate to high rainfall (150-200 cm annually) with a short dry season.
- Canopy: Less dense than evergreen forests, with some trees shedding their leaves during the dry season.
- Biodiversity: High biodiversity but generally lower than that of tropical evergreen forests.
- Soil: Fertile but can vary, often rich in organic matter with better nutrient retention compared to evergreen forests.
Flora:
- Dominant tree species include Teak, Sal, Sandalwood, and Terminalia species.
- A mix of evergreen and deciduous trees, with deciduous species shedding leaves during the dry season.
- The understory includes a variety of shrubs, herbs, and ferns.
Fauna:
- Similar to tropical evergreen forests but often with fewer species due to slightly drier conditions.
- Mammals like tigers, leopards, elephants, deer, and various monkeys.
- Birds, reptiles, and amphibians are abundant, along with a diverse insect population.
Example:
- Andaman and Nicobar Islands: These islands host significant areas of semi-evergreen forests. The unique climate and isolation of these islands have resulted in a mix of endemic species and rich biodiversity.
- Northeastern India: States like Assam and Meghalaya have extensive tracts of semi-evergreen forests, particularly in regions like the Khasi and Jaintia Hills.
Significance:
- These forests are vital for maintaining ecological balance, providing habitat for numerous species, and supporting hydrological cycles.
- They are also important for local economies, providing timber, fuelwood, and non-timber forest products.
Summary
Tropical Evergreen and Semi-Evergreen forests are crucial ecosystems in India, contributing to biodiversity, climate regulation, and local livelihoods. The Western Ghats and the Andaman and Nicobar Islands are prime examples of these forest types, highlighting their ecological importance and the need for conservation efforts to protect these rich natural resources.
