Terrestrial Habitat – Forest

FOREST

A forest is a plant community in which tree species are dominant. There are different kinds of forests, whose distribution is determined mainly by climate (particularly rainfall and temperature), but sometimes by elevation, soil factors and the activities of man, such as farming lumbering, cutting of firewood, bush burning, road construction and building construction. Forest used to cover most of southern Nigeria but the area covered by forest has been reduced by human activity. The rain forest is the major type of forest in Nigeria.

Characteristics of the Tropical Rain Forest

1. The forest is rich in epiphytes and climbers.
2. The interior of the forest has high humidity, low light intensity and damp floor.
3. Tall trees with canopy strata.
4. Trees are mesophytes with broad leaves.
5. Leaves of all trees have long drip tips to facilitate dripping off of water.
6. The vegetation has a pattern of arrangement in storeys or layers.
7. The forest floor is usually open with little vegetation.
8. There is usually a large amount of leaf litter on the forest floor
9. Leaves of all trees have long drip tips to facilitate dripping off of water.
10. Rainfall is usually very high.

Strata in a Rain Forest

The plants in a forest may be classified into five storeys or layers which are briefly described as follows:

1. The Emergent layer
2. The Upper layer
3. The Middle layer
4. The lower layer
5. The Ground layer/forest floor
6. The Emergent Layer: This is the topmost layer or storey made up of the tallest trees, over 40m tall, called emergents. The crowns of the emergents do not normally touch one another.
7. The Upper Layer: this is the second storey or layer and is made up of tall trees, between 20m and 40m tall. Their crowns touch, forming a continuous canopy below the emergents.
8. The Middle Layer: The third layer is made up of small trees, less than 20m tall, which also form a continuous canopy below the second or upper storey.
9. The Lower Layer: Below the third layer of trees is the shrub layer.
10. The Ground Layer/Forest Floor: the ground layer consists of shade-tolerant plants, including mosses and ferns.

Distribution of Plants and Animals in the Rain Forest

Plants: Plants such as Mahogany, Mango trees, Coconut trees, Oil palm, Orchids Ferns and herbs.

Animals: There are Birds, Squirrels, Snakes, Toads and Snails.

Adaptive Features of Tropical Rain Forest Organisms

Plants (Morphological Features)

1. Trees have broad leaves to increase rates of transpiration or gaseous exchange of leaves pointed to increases exposure to sunlight.
2. Leaves have pointed draw-out tips, for easy dripping of water or to prevent growth of fungi or algae underneath.
3. Trees have thin back, to facilitate transpiration or gaseous exchange.
4. Plants with twining stems, for climbing up to source of light.
5. Presence of hydathodes, for guttations etc.

Animals

These include animals with gasping pads, e.g. tree frogs, grasping scales, e.g. snakes, the ability to fly, e.g. birds, ability to jump, e.g. monkeys.

Example of food chain existing in the Habitat

Palm fruit     →     Squirrel     →      Snake     →      Bird.

EVALUATION (POST THE QUESTION TITLE AND YOUR ANSWER IN THE QUESTION BOX BELOW FOR EVALUATION AND DISCUSSION)

1. What determines the tropical rain forest?
2. State four characteristics of the rain forest.
3. Outline the strata in the rain forest.
4. Mention five plants and animals in the rain forest.
5. Write two adaptive features each of plants and animals in the rain forest.