TERRESTRIAL HABITAT: MARSH, FOREST, GRASSLAND AND ARID LAND

TERRESTRIAL HABITAT

Terrestrial habitat is where land form a living place for organisms.

Types Of Terrestrial Habitat

Four major types of terrestrial habitat are

  • Marsh
  • Forest
  • Grassland (Savannah)
  • Arid land (desert) 

MARSH

A marsh is a lowland area which is flooded at all times and in which grasses and shrubs grow. It is a transitional habitat between aquatic and terrestrial habitat. 

Characteristics of a marsh

  • It is a lowland habitat.
  • The ground is flooded.
  • There is wet, soft and water-logged soil.
  • There is high relative humidity.
  • It contains much decaying organic matter.
  • There is low oxygen content due to decaying organic matter giving it a foul smell.

 

Types of Marsh

Major types of Marsh are

  • Freshwater marsh found in hinter land.
  • Saltwater marsh found along the coast e.g. Lagos lagoon.

In Nigeria, saltwater marshes are found in a belt along the Atlantic coast, which is influenced by tides.

Freshwater marshes occur inland, just beyond the limits of the saltwater marshes and beyond the area influenced by tides.

 

Formation of Marshes

Marshes occur in areas of lowland and where drainage is poor. Marshes may develop as a result of water overflowing its banks to accumulate on the adjoining coastal or lowland area. Marsh can be formed when ponds and lakes are filled up with soil from the surroundings and organic debris from plants causing waterlogging. Formation of Marsh may also be enhanced with extensive rainfall which also contribute to the accumulation of water on a land surface.

 

Distribution of organisms in marsh

  • In freshwater marsh, plants are water lettuce, lemna, and algae that float on top, water lyacinth.

Animals such as frogs, toads and fishes are also found.

  • In saltwater marsh, animals found include mangrove-crab, lagoon-crab, hermit crab, mudskipper fish, bloody clam oysters, barnacles.

 

Adaptation of organisms marsh

They have the ability to adapt to salty environment, waterlogging and low oxygen content.

FOREST

Forest is a habitat where plant communities is dominated by tree species.

Types of forest.

Two types of forest are:

  • Mangrove swamp forest.
  • Tropical rainforest.

Mangrove swamp forest

Mangrove swamp forest are found in Nigeria in states like Delta, Cross River, Akwa-ibom, Bayelsa, Ogun and Lagos State.

Characteristics of Mangrove Swamp Forest

  1. It has tall Woody trees.
  2. Plants have aerial roots.
  3. It has evergreen trees with broad leaves.
  4. It has high rainfall through the year resulting in waterlogging.

 

Distribution of organisms in mangrove swamp

  • Common plants found are:

white mangrove — Avicena nitida

Red mangrove — Rhizophora racemosa, raffia palm and coconut.

  • Animals found here are:

Snakes, crabs, birds, Kingfishers, starfishes, mosquitoes, Tilapia fish, mollusca.

 

Tropical rainforest

In tropical rainforest, rainfall is evenly distributed in luxuriant vegetation. This type of forest is found in Oyo, Lagos, Osun, Edo, Delta, Akwa-ibom, Cross River, Abia, Imo, Anambra, Ogun, Ondo, Rivers State.

 

Characteristics of tropical rainforest

  1. Rainforest is throughout the year.
  2. It has a high temperature of 25 – 37°C.
  3. Low light intensity.
  4. Damp floor
  5. It has abundant sunshine.
  6. Relative humidity is high (abiotic factors).

Other biotic characteristics are:

  1. Forest trees have broad ever green leaves, unbranched truncks with buttress roots which gives support.
  2. Trees have different layres or canopy
    1. Ground layer or forest floor.
    2. Shrub layer.
    3. Lower layer.
    4. Middle layer.
    5. Upper layer.
  3. Forest is rich in epiphytes and climbers.

Profile Of A Tropical Rainforest

 

Distribution of Organisms in forest zones.

Forest plants are distributed according to their needs for light and ability to withstand exposure. On forest floor are shade-tolerant plants, such as ferns and saprophytic fungi. Some ferns are found on tree trunks and branches. Mistletoe is one of the most light-demanding epiphytes and are found high up in the trees. Other light lovers are iroko, mahogany, silk cotton, coconut, oil palm, mango, orchids, obeche, ebony.

Many forest animals live on the tree. They include monkeys, squirrels, snakes,bats, birds, lizards, tree frogs and chameleons. Some forest animals such as earthworm and beetles, love in the soil. Others, such as millipedes, ants and snails live amongst the leaf litter on the surface of the soil.

 

Adaptation of forest organisms

Plants:

  1. Some plants have well developed root system for support and for absorption of water and mineral salts from the soil eg. iroko, mahogany.
  2. Climbers possess hooks on their roots for holding their support.
  3. They possess supporting and strengthening tissues (the xylem).
  4. Trees have tall and unbranched truncks to enable them reach the source of light.
  5. Some have thin bark to facilitate gaseous exchange.
  6. Some have clasping roots for support.
  7. Some have buttress roots for support eg. iroko, mahogany.
  8. Others have hydathodes for guttation.

Animals:

Most of the animals in forest zones shows adaptation for aboreal habitat.

  1. Ability to fly eg. birds, flying squirrel and bats.
  2. Ability to climb eg.
  3. grasping pads for holding the tree eg. tree frogs.
  4. Sticky disc on fingers eg. gekos.
  5. Prehensile tails eg. chameleon.
  6. Grasping scales eg. snakes.
  7. Ability to jump from branch to branch eg. monkeys.

GRASSLAND OR SAVANNAH

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

 

Characteristics of Grassland

  1. Moderate to low rainfall.
  2. Dry and hot environment.
  3. Bush fires are common in the dry season.
  4. The soil is usually Sandy.
  5. The moderate rainfall and high temperature make water conservation very necessary for plants and animals.

 

Types of Grassland

Grassland are classified into tropical and temperate, depending on the whether they occur in tropical or temperate zones respectively. Temperate or tropical grasslands are given different names in different countries, such as, Savannah of West Africa, the pampas of Argentina  – for tropical grassland, the steppes in Asia and the prairies in North America – for temperate grassland.

In Nigeria, there are different types of Savannah:

  1. Guinea savannah which is composed of
    1. Southern guinea savannah
    2. Northern guinea savannah
  2. Sahel savannah
  3. Derived savannah.
  4. Sudan savannah.

Distribution of plants and animals in the savannah

In Savannah vegetation, grass species are dominant. Trees and shrubs are much less numerous than in forests and are scattered thinly across the land. Grasses occur in the spaces between the trees.

The savannah is very rich in animal population. In the soil, there are many animals such as termites whose termite mounds dot the landscape. On the land, there are many herbivores, such as rats, squirrels, deer, porcupines, gazelles, grass cutters and antelopes. Carnivores include snails, cheetahs and leopards.

 

Adaptation of plants and animals in the savannah.

Plants:

  1. Most plants set and disperse their fruits in dry season because they are adapted for wind pollination.
  2. Possession of waxy surface and hairy leaves by the plants reduce transpiration, thus enables the plant to survive drying winds.
  3. Leaves are shed by the trees in the dry season to conserve water.
  4. Possession of thick bark insulates the trees from fire damage.
  5. Several plants possess underground stems that are adapted to seasonal draught.
  6. Many plants have deep penetrating roots to search for water.

Examples of plants in the grassland are mahogany bean, shea butter, tamarind and baobab.

 

Animals:

  1. Nutrient adaptation as most animals feed on grass or grass parts.
  2. Fast moving large herbivores like zebra with good eye sight were able to feed on vegetation spread over a large wide area.
  3. Fast moving large herbivores can also detect predators and run swiftly in an open habitat that is devoid of hidden places.

Examples of Animals in the grassland are zebra, antelope, giraffes, elephants.

 

Food chain in Grassland

Grass —> Zebra —> Lion

ARID LANDS

Arid lands are those in which water is very difficult to obtain, either because I’ve is scarce or because it is frozen.

 

Types of arid lands

There are two main types of arid lands, namely;

  1. Hot arid lands, which are hot deserts and semi-desert; and
  2. The cold arid lands, which are the cold deserts or tundra.

These two kinds of arid lands have different types of characteristics.

 

 

Characteristics of tropical arid lands

  1. Water is very scarce because rainfall is very low (below 250mm per annum) and falls irregularly.
  2. Temperatures are very high by day and very low by night.
  3. The soils are sandy or rocky.
  4. Sunshine is very intense since there is little vegetation to provide cover.
  5. The vegetation is very poor.
  6. Winds are usually quite strong.

In contrast, the tundra is very cold and the ground surface is covered with ice throughout the year, except during the short summer.

 

Distribution of Organisms in hot arid lands

Only a limited number of plants species can live in arid lands. These includes some species of grasses, thorny shrubs and plants of the cactus family. Date palms occurs around oases (areas where is a local source of water).

Few animals live in arid lands. These often live in burrows to avoid the harsh weather.

 

Adaptation of Organisms in arid lands

Adaptation for water conservation by plants and animals in arid lands include the following:

Plants:

  1. Some plants have underground stems which remain alive when the aerial parts die.
  2. Cacti and other plants have no leaves, so as to check transpiration. The leaves are modified into or thorns,or are entirely absent. The stems are green and carry out photosynthesis.
  3. Some plants, such as cacti, store water in their fleshy stem.
  4. Some plants have very long roots which can absorb water from deep down in the soil.
  5. Some plants have sunken stomata or hairs on leaves to reduce transpiration e.g. Eucalyptus.
  6. Some plants, can complete their entire life cycle in the very short period when rains occur, then they die and survive the long dry season in the form of seeds.

 

Animals:

  1. The camel can go a long distance and for several days with one drink of water.
  2. Many desert animals excrete solid waste substances and hence avoid losing water as urine.
  3. Desert rats use very little water and depend largely on water present in the food they eat.
  4. Living in burrows and coming out to feed at night when it is cool helps desert animals to minimise water-loss.
  5. Sweat glands of desert animals are not very active and this is a check against water-loss.
  6. Reptiles in arid lands have scales which limit their water-loss.
  7. Adaptation for the regulation of body temperature e.g. many animals avoid the very high day temperature by living in burrows.
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