Terrestrial Habitats

CONTENT

• Terrestrial Habitats
• Marsh
• Forest
• Grassland
• Arid land

TERRESTRIAL HABITATS

Organisms of the land are called terrestrial organisms. They include plants and animals that are found living on the ground and under the ground.

Basically, terrestrial habitat is subdivided into four main parts, namely;

1. marsh
2. forest
3. grassland/ savanna
4. arid land/ desert

EVALUATION

1. What are terrestrial organisms?
   1. List four types of terrestrial habitats

MARSH

Marsh is a low land, flooded in rainy season and usually waterlogged because of poor drainage. The vegetation is predominantly of grasses and shrubs. When trees grow in a marsh, it is called a swamp. Marsh is a transition between the aquatic habitat and terrestrial habitat.

FORMATION OF A MARSH

Marshes develop as a result of water overflowing its banks to accumulate on the adjoining coastal or low land area such as flood plains of rivers. This can be enhanced with extensive rainfall.

When ponds and lakes are filled up with soil and organic debris of plants, marshes can also be formed. Marshes formation is therefore a gradual process. Marshes can either be fresh water or salt water marshes.

CHARACTERISTICS OF A MARSH

1. A marsh is lowland.
2. It is always flooded, wet and waterlogged.
3. It sometimes has pool of standing water.
4. It has a high relative humidity
5. Its water sometimes contain much decaying organisms
6. The water has a foul smell

ORGANISMS OF THE MARSH

There are various plants and animals in this habitat. The plants include algae, grasses, water lettuce, water lilies, white and red mangrove, raphia palms e.t.c.

Animals found in the marsh include mangrove crabs, lagoon crabs, hermit crabs, mud-skippers, fishes, frogs, snakes, crocodiles, mammal e.t.c.

Adaptive features of organisms of the marsh include

1. They must be able to tolerate the salinity of the soil or water
2. They have to tolerate low oxygen concentration in the soil or water

Plants of fresh water marsh have other adaptive features similar to those of fresh water habitat. Likewise the plants of salt water marsh.

Saprophytic organisms (e.g. bacteria) which live on dead organic matter in marshes have to adapt to anaerobic condition.

FOOD CHAINS IN MARSHES

1. Flowering plants → insects → frogs → crocodiles
2. Humus → earthworms → frogs → snakes

EVALUATION

1. How is a marsh formed
2. State four characteristics of a marsh
3. List four plants and animals found in the marsh

FORESTS

A forest is a community of plants in which trees species are dominant. There are different kinds of forest whose distribution is determined mainly by climatic factors such as temperature, rainfall and at times by soil elevation and man’s activities such as farming, lumbering, bush burning, construction of roads and building.

The major type of forest in Nigeria is the rain forest

CHARACTERISTICS OF A 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. Presence of tall trees with canopies and existing in layers (stratified).
4. Trees are mesophytes with broad leaves.
5. The trees have buttress roots to support their heavy weight and height.
6. The trees have thin barks for gaseous exchange and transpiration.

PLANTS DISTRIBUTION AND ADAPTATION

Forest plants (trees) include African walnut, mahogany, teak, obeche, iroko, oil palm, ferns (pteridophytes), bryophytes (mosses and liverwort), epiphytes (orchid), fungi and mistletoe e.t.c. these plants adapt to life in the forest in the following ways;

• Possession of strong tap root systems and buttress roots.
• Possession of tall unbranched trunks
• Possession of broad leaves
• Epiphytes have mechanism (the aerial roots) storing water and absorbing moisture from air while growing on tree branches.
• Mistletoe (plant parasite) develops root system that can penetrate the stem of a plant withdrawing manufactured food directly from phloem vessels of the host plant.

ANIMALS DISTRIBUTION AND ADAPTATION

Most forest animals are arboreal (living on trees) and these include bats, monkeys, snakes, squirrels, birds, tree frogs, chameleons. Some live in the soil e.g. earthworms and beetles while others live among the litters on the ground e.g. millipedes, ants, snails.

These animals adapt to the forest in the following ways

• Monkeys have prehensile tails and long limbs for climbing and jumping.
• Bats modify their limbs into wings for flight
• Green snakes have protective colouration to camouflage
• Chameleon has prehensile tail and opposable digits for grasping as well as protective colouration to camouflage
• Apes moves in groups for protection, with high sense of sight
• Earthworms and snails have water permeable cuticle to reduce water loss and prevent desiccation.
• Birds have powerful wings for flight

FOOD CHAINS IN A FOREST

1. Green plants → grasshoppers → toads →hawks
2. Green plants → monkeys → lions

EVALUATION

1. Describe a forest habitat using its characteristics
   1. Give two examples of food chain in a forest

GRASSLAND [SAVANNA]

This is a plant community in which grass species are dominant, but trees and shrubs may be present.

CHARACTERISTICS OF GRASSLAND

1. Temperature is usually high and sunshine is intense.
2. The relative humidity is low and rainfall scanty (60 – 150cm annual rainfall).
3. Abundant grassland with few short trees sparsely distributed
4. Bush fire is frequent and trees are fire resistant
5. Deciduous plants (plants that shed their leaves in dry seasons) are present.
6. Plants possess underground stems and deep roots to search out for water
7. Trees have modified leaves for adaptation to the environment

TYPES OF SAVANNA

Basically, there are four major types of savanna in Nigeria, namely;

1. Southern guinea savanna
2. Northern guinea savanna
3. Sudan savanna
4. Sahel savanna

Southern guinea savanna is the largest biome in Nigeria

PLANTS DISTRIBUTION AND ADAPTATION IN GRASSLANDS

The grassland plants include acacia, elephant grass, guinea grass, spear grass, palms, baobab trees e.t.c. their adaptive features include

• Trees have thick corky barks to resist severe fire
• Grasses with underground stems to escape fire and drought
• Leaves with waxy surface in addition to cuticle covering to reduce transpiration
• Reduced or small leaves to reduce transpiration
• Presence of curly leaves to conserve water
• Leaves fall (deciduous) in drying season to conserve water
• Baobab trees have broad and succulent leaves to conserve water

ANIMALS DISTRIBUTION AND ADAPTATION IN A FOREST

Animals found in the forest include antelopes, elephants, giraffes, zebras, goats, cattle, grasshoppers, lizards, birds, lions, tigers, leopards, rats, snakes, grass cutters, kangaroos e.t.c. They adapt to this habitat in the following ways

• Termites lived in air conditioned nests called anthills for cooling the animals.
• Rats burrow into the soil to avoid excessive heat and fire
• Zebras and giraffes can camouflage using their colours.
• Lions, tigers and leopards have powerful claws and teeth for attacking animals.
• Kangaroos have long legs to help them escape from danger and also have pocket of flesh to shield their young ones from hot weather and attack.
• Elephants and lion move in groups or herds to achieve strength in number

FOOD CHAINS IN GRASSLAND

There are several food chains due to numerous animals

1. Grass → grasshoppers→ lizards → snakes
2. Grass → grasshoppers → toads → birds
3. Grass → zebras → lions

EVALUATION

1. Describe a grassland
2. State four characteristics of a grassland
3. List 4 plants and 4 animals of the grassland and explain how each adapt to this habitat

ARID LANDS [DESERTS]

These are areas of very low rainfall and high evaporation rate. They are the driest habitats, receiving less than 25cm annual rainfall. Arid lands are of two types;

• Hot deserts e.g. Sahara desert (North Africa), Kalahari desert (South Africa)
• Cold deserts e.g. desert in North America

CHARACTERISTICS OF A DESERT

1. Water is very scarce
   1. Temperature is very high by the day and very low by the night
   1. Vegetation is very scanty
   1. The soils are sandy or rocky
   1. Strong winds occur frequently and sunshine very intense
   1. Presence of drought resistance plants (xerophytes)

PLANTS DISTRIBUTION AND ADAPTATION IN DESERTS

Deserts plants include thorny bushes, cacti, scattered dwarf acacia, date palm, wiring grasses, baobab trees and euphorbia species. They adapt to this habitat in the following ways;

• Plants have thin leaves to reduce transpiration
• Cacti leafless have thorns to reduce transpiration and thick succulent stem to store water
• Acacia (drought resistant) has deep roots which absorb underground water
• Baobab tree has waxy leaves which can be hairy or needle shaped to reduce the rate of transpiration
• Wiring grass has narrow and slender leaves to reduce transpiration.

ANIMAL DISTRIBUTION AND ADAPTATION IN DSERTS

The deserts animals include camel, rodents, lizards, snakes, zebras, desert tortoise, grasshoppers, wasps, ants e.t.c. They survive in the following ways;

• Most desert animals excrete solid wastes to conserve water.
• Kangaroos, rats remain in burrows during the day to avoid excessive heat
• Reptiles have scales to reduce water loss
• Camels can survive several days without drinking water. They can withstand a wide range of body temperature up to 40^oc.
• Locusts have water-proof bodies and impervious cuticles

FOOD CHAINS IN ARID LANDS

1. Plants → desert rats → snakes
2. Plants → ants → scorpions → snakes

EVALUATION

1. Describe the desert
   1. State four characteristics of tropical arid land

GENERAL EVALUATION

1. List the two types of arid land with examples.
   1. Mention four plants and four animals of the desert and explain how they adapt to life in this habitat.
   1. List four characteristics each of (i) Trees of the tropical rain forest (ii) Trees / shrubs of the savanna.
   1. State five adaptive features of animals that climb forest trees.
   1. Mention four characteristics of a desert.

WEEKEND ASSIGNMENT

1. Marsh is a ……… flooded and waterlogged     (a) highland      (b) lowland    (c) island   (d) mountain
2. Marsh is described as a ……… when trees grow there     (a) swamp     (b) forest                      (c) puddle    (d) desert
3. Dominant plants in the forest are    (a) grasses    (b) shrubs   (c) trees    (d) vegetables
4. An examples of forest plants’ parasite is    (a) orchid     (b) mosses     (c) liverwort                   (d) mistletoe
5. The plants of the forests are described as     (a) hydrophytes     (b) mesophytes                     (c) xerophytes     (d) neophytes

THEORY

1. What is a marsh? State two types of a marsh
2. State five unique features of a forest

READING ASSIGNMENT

College Biology, chapter 23, page 507 – 523