Third Term

Week 4





1. Forest

  • Characteristics of Forest
  • Strata in a Rain Forest
  • Distribution of Organisms in a Forest
  • Adaption of Plants and Animals in a Forest
  1. Grassland
  • Characteristics of Grassland
  • Distribution of Plants and Animals in Grassland
  • Some Adaptation of Grassland Communities
  1. Arid Land
  • Characteristics of Arid Lands
  • Types of Arid Lands
  • Distribution of the Organisms to Arid Lands
  • Some Adaptation of Organisms to Arid Lands



A forest is a plant neighborhood during which tree species are dominant. There are totally different sorts of forests, whose distribution is decided primarily by local weather (significantly rainfall and temperature), however typically by elevation, soil components and the actions of man, akin to farming lumbering, chopping of firewood, bush burning, highway development and constructing development. Forest used to cowl most of southern Nigeria however the space lined by forest has been lowered by human exercise. The rain forest is the foremost sort of forest in Nigeria.

Traits of the Tropical Rain Forest

  1. The forest is wealthy in epiphytes and climbers.
  2. The inside of the forest has excessive humidity, low gentle depth and damp ground.
  3. Tall timber with cover strata.
  4. Bushes are mesophytes with broad leaves.
  5. Leaves of all timber have lengthy drip tricks to facilitate dripping off of water.
  6. The vegetation has a sample of association in storeys or layers.
  7. The forest ground is often open with little vegetation.
  8. There’s often a considerable amount of leaf litter on the forest ground
  9. Leaves of all timber have lengthy drip tricks to facilitate dripping off of water.
  10. Rainfall is often very excessive.

Strata in a Rain Forest

The crops in a forest could also be categorized into 5 storeys or layers that are briefly described as follows:

  1. The Emergent layer
  2. The Higher layer
  3. The Center layer
  4. The decrease layer
  5. The Floor layer/forest ground
  1. The Emergent Layer: That is the topmost layer or storey made up of the tallest timber, over 40m tall, referred to as emergents. The crowns of the emergents don’t usually contact each other.
  2. The Higher Layer: that is the second storey or layer and is made up of tall timber, between 20m and 40m tall. Their crowns contact, forming a steady cover under the emergents.
  3. The Center Layer: The third layer is made up of small timber, lower than 20m tall, which additionally kind a steady cover under the second or higher storey.[mediator_tech]
  4. The Decrease Layer: Under the third layer of timber is the shrub layer.
  5. The Floor Layer/Forest Ground: the bottom layer consists of shade-tolerant crops, together with mosses and ferns.

Distribution of Crops and Animals within the Rain Forest

Crops: Crops akin to Mahogany, Mango timber, Coconut timber, Oil palm, Orchids Ferns and herbs.

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

Adaptive Options of Tropical Rain Forest Organisms

Crops (Morphological Options)

  1. Bushes have broad leaves to extend charges of transpiration or gaseous trade of leaves pointed to will increase publicity to daylight.
  2. Leaves have pointed draw-out suggestions, for straightforward dripping of water or to forestall development of fungi or algae beneath.
  3. Bushes have skinny again, to facilitate transpiration or gaseous trade.
  4. Crops with twining stems, for climbing as much as supply of sunshine.
  5. Presence of hydathodes, for guttationsetc.


Morphological traits of stems in addition to whole shoots embrace size or peak, seasonal patterns of internode lengths, node density, whole leaf space, and the density and distribution of flowers, fruits, leaves and buds (Bonser and Aarssen 1994; Canham 1988; Dahlem and Boerner 1987; Huff man et al.


Temperate Rain Forest

Though scattered pockets of temperate rain forest are discovered from Mount Rainier northward into coastal British Columbia, nowhere is their growth as pronounced as within the Hoh, Queets, and Quinault river drainages alongside the Pacific coast of the Olympic Peninsula in Washington State. These bowl-shaped river valleys had been scoured out over the last ice age, and the river valley form and local weather mix to permit these temperate rain forests to flourish.


These embrace animals with gasping pads, e.g. tree frogs, greedy scales, e.g. snakes, the power to fly, e.g. birds, means to leap, e.g. monkeys.

Instance of meals chain current within the Habitat

Palm fruit     →     Squirrel     →      Snake     →      Chook.



  1. What determines the tropical rain forest?
  2. State 4 traits of the rain forest.
  3. Define the strata within the rain forest.
  4. Point out 5 crops and animals within the rain forest.
  5. Write two adaptive options every of crops and animals within the rain forest.



Grasslands are areas the place the vegetation is dominated by grasses and different herbaceous crops. In West Africa, savannah vegetation is about crucial forms of vegetation. In Nigeria, over 80% of the vegetation is one sort of savannah or one other.

Traits of Grassland

  1. The savanna vegetation is typified by tall grasses and scattered timber and shrubs. The species of grasses within the sudan and sahel savannah are annuals which frequently have cylindrical leaves to scale back transportation. In the course of the dry season, the leaves of the grass flip yellow and die however the roots stay dormant. The grasses are deciduous.
  2. Savannah timber have thick barks which shield them from the impact of fireside. Many of the timber are deciduous, they shed their leaves in dry season to scale back lack of water by transpiration and due to annual fireplace. The timber have lengthy roots (e.g. acacia) to go looking to seek for floor water.
  3. Savannah vegetation is often not as luxuriant because the forest vegetation. It is because the timber are fewer, smaller in construction and scattered throughout the savannah habitat.
  4. The annual burning and fireplace within the savanna scale back the standard of the humus within the soil, whereas the ash retains some minerals salts that are washed into the soil throughout rains.
  5. Rainfall is often reasonable (1000 -1500 min per yr) distributed over 6 to eight months of the yr. The dry season is longer within the savanna than the forest area.
  6. Savannah soil is often sandy, shallow of relative decrease fertility than the forest soils.
  7. Dry seasons bush fires and livestock grazing are frequent within the tropical savannah.


Fouta Djallon Savanna

Whereas a lot of the Fouta Djallon area in Guinea is a rugged mountain plateau minimize by deep valleys, the jap portion is gently sloping land lined partly by savanna. The most important ethnic group of the area is the Fulani, lots of whom increase cattle on the grasslands. The Fulani arrived within the area in in regards to the tenth century, and later established a sequence of kingdoms all through the realm which stood till defeated by colonial powers within the late nineteenth and early twentieth centuries.

Sorts of Grasslands

The 2 principal forms of grassland are tropical and temperate savanna. Tropical savannas happen in West and East Africa, Southern Africa, north of the tropic of Capricorn, a part of Brazil, north and east of Australian Desert and a part of Indian deccan Plateau. About 80% of the vegetation of Nigeria is savanna sort.

The various kinds of savanna vegetation in West Africa embrace – the Guinea savanna, the Sudan savanna and the Sahel savanna.

Temperate grassland consists of the Steppe of Asia, Prairies of North America, Pampas of Argentina, Veldt of South Africa and Downs of Murray Darling Basin of grasslands are nearly treeless. Among the many timber of temperate grassland are poplars, willows and alders.


Savanna Elephant

The savanna elephant is the biggest of the three species of elephants. Savanna elephants stay in grasslands and drier woodlands all through Kenya, Tanzania, Botswana, Zimbabwe, Namibia, and South Africa.

Distribution of Crops and Animals in Grasslands

Grass is the dominant vegetation of the savanna. These shrubs and herbs are scattered within the savanna whereas grasses cowl the soil inside them. Within the guinea savanna are broad leaved timber, whereas additional north within the sudan and sahel savanna the timber are extra scattered and shorter. There are thorny timber with slim leaves- to scale back transpiration and face up to the extended drought.

Palms which can’t face up to the drought are restricted to the wettest space or alongside the rivers.

Tropical savanna is the house of untamed animals. The animals inhabitants embrace herbivores like caterpillars, grasshoppers and birds which feed on grass seeds, grazing animals like cows, goats, sheep and wild herbivores like antelope, deer, elephant, giraffe and okapi.

Carnivores embrace lion tiger, leopard panter, jacka; and cheetah. Alongside the rivers and marshy lakes are a number of species of reptiles akin to alligators, crocodiles, large and monitor lizards; and mammals akin to hippopotamus and rhinoceros. There are additionally quite a few species of birds, butterflies, moth and different bugs.

Some Adaptation of Grassland Communities

Variations of Savanna Animals

The primary variations of savanna animals embrace the next:

  1. Adaptation for drought which embrace burrowing into the bottom by animals such because the rats and constructing of nicely ventilated terminals by termites.[mediator_tech]
  2. Variations akin to sharp claw and enamel of the carnivores for catching their prey; and quick motion to catch them.
  3. Sharp imaginative and prescient, sharp listening to and quick motion of prey to flee from the predators and dwelling collectively in teams or herd to make sure safety for his or her members.

Variations of Savanna Crops

The primary variations of the savanna crops embrace the next:

  1. Adaptation of savanna crops for drought embrace shedding of leaves, possession of tiny leaves with extremely lowered floor space, possession of thick cuticle over the leaf floor and discount within the variety of stomata on the leaves. Many crops possess underground stem via which tides them over the drought interval.
  2. Adaptation of savanna crops for annual fireplace embrace: the thick and cropy barts of the woody crops, possession of fire-restricted twigs; speedy regeneration shortly after fires by suckering and coppicing, possession of varied  strategies of regeneration vegetative after fires by herbs. That is by means of organs akin to bulbs, tubers, corms and rhizomes, that are buried under. The crops additionally produce quite a few seeds which might stay buried within the soil and sprout shortly throughout the rains.




  1. Focus on the distribution of crops and animals within the tropical savanna of West Africa
  2. What are the adaptive options of grassland animals?
  3. What are the attribute of Tropical grassland?
  4. State 3 ways by which savanna crops adapts themselves to the annual bush burning
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