Grassland biotic factors

Introduction

Grassland biotic factors are the living component of this region, it is called grassland because it is covered by grass. About 20% of the earth’s surface is covered by grassland, this region belongs to the terrestrial ecosystem. Grasslands are developed in the central part of the continent where the average annual rainfall is 90 to 150 cm.

Biotic factors are the biological part of the environment and are usually obtained from the biosphere. A region has certain elements that directly or indirectly affect that region. The biotic factor is one such factor that indirectly affects grasslands. These biotic factors interact with the abiotic factors of a region to maintain the balance of the environment.

Grassland is a flat and exposed region. There are various types of plants and organisms living in grassland. Here we will discuss the grassland biotic factors and their role in this region (1) & (2).

Grassland

A large, flat, and open area on the earth that is covered with different types of grasses,  is known as grassland. It is specially used for grazing. Grasslands were developed during the Cenozoic era about 65.5 million years ago.

This region is formed where there is not enough regular rainfall to support the growth of a forest but not so little that a desert forms. That means, most of the world’s grasslands are formed in temperate regions.

Grassland is an area where the grass is predominant. These regions are located in the interior of the continent, inhabited by westerly winds. Due to its location on the interior of the continent, rainfall is moderate. This is why the presence of trees in this region cannot be noticed. The main natural vegetation of the grasslands is grass (2).

Location of grassland

Grassland is the second most abundant region in the world after forests. It is located between forest and desert. The region is present in areas where rainfall is about 50 to 100 cm per year. All these regions of the world are various parts of North America, South America, Australia, Europe, South Africa, Eurasia, etc. Grasslands of each place are known by different names.

• North America- Prairies
• South America- Selvas
• Australia- Downs
• Europe- Taiga
• South Africa- Veld
• Eurasia- Steppe
• Argentina- Pampas (5) & (6).

Grassland characteristics

1. A grassland region grows different types of grasses, such as tor grass, blue moor-grass, false oat-grass, rough meadow-grass, cocksfoot, etc.

2. Mainly there are three types of grassland, such as tropical, temperate, and polar grassland.

• Temperate grasslands are cold in winter and warm in summers.
• Polar grassland temperature is always below 0°.
• Tropical grasslands are dry and wet all the seasons.

3. Mainly two seasons are present in this region such as summer and winter.

4.There is a wide variation in winter and summer temperatures in this region.

5. Here, temperatures can drop -40°F during the winter season.

6. The grass is the main natural vegetation in the region so it is known as the transitional zone.

7. The climate of the grassland region is temperate types (4) & (6).

Grassland biotic factors

Biotic components in grassland mention all living organisms from animals and humans, to plants, bacteria, and fungi. They play an essential role in this region. Grasslands biotic factors are as follows

1. Producer or plants

Producers are the main biotic components of this region. Grasses, shrubs, small trees, mosses, lichens, and cyanobacteria, etc. are the producers in the grassland region.

But the grass is the main producer of grassland. When the plant dies, the decomposer present in this region decomposes the plant body. After decomposing in this way, various minerals of the plant body mix with the soil to increase the fertility of the soil. So the grassland’s soils are very fertile.

Some characteristics of producer

• The producers of the region have a good relationship with the climate and the soil.
• Only one layer of plants can be noticed in this grassland. However, in some places, some layers of plants are formed on the basis of climate and rainfall.
• The producers bound the solar energy in their bodies and supplied the energy to the consumers that lived in this region.
• Grasses in this region are always flowering.
• In the process of photosynthesis, they make food with the help of chlorophyll in the presence of sunlight.
• Numerous species of plants are present in this region which is more than the number of consumers in this region.
• The plants or producers protect the grassland’s environment from being polluted by supplying oxygen to the air.

Types of grasses

There are mainly three types of grasses found in the grassland.

• Tall grasses

These types of grasses are found in the eastern part of North America. Little bluestem, big bluestem, switch, tor grass, etc. are tall grasses. Bluestem is also called beard grass. Their length is about 1.5 to 2.4 meters. Occasionally oak and hickory plants are observed.

• Middle grasses

The grasses of this region are medium size. Their length is 0.6 to 1.2 meters. Needlegrass, June grass, Buffalo grass, etc. are these types of grass. Buffalo grass is clustered.

• Short grasses

Blue fescue, dwarf fountain grass, muhly grass, Chinese silver grass, sedges, etc. are short-type grass. Their length is less than 0.6 meters.

Types of plants

False oat-grass, rough meadow-grass, cocksfoot, aristida, cynodon, setaria, elephant grass, Rhodes grass, ryegrass, agropyron, asters, blazing stars, blue grama, Some small trees, shrubs, mosses, lichens, etc. are found in grassland.

Producers play an important role in the environment of grassland. They create oxygen to protect the entire species and microorganisms in this region (5).

2. Primary consumer or invertebrates

• Primary consumers depend on the producer for food.
• Consumers are heterotrophs.
• They do not produce their own food.
• There are three types of consumers seen in this region. Primary consumers are mainly herbivorous. The primary consumer eats only green plants and grasses.
• These consumers are directly dependent on producers. They take in oxygen from the environment during respiration.
• The amount of biomass is very high in primary consumers.
• They are cut across a wide range of ecological niches.

Some primary consumer example

Buffalo, zebras, antelopes, giraffes, cows, goats, deer, rabbits, moose, sheep, bison, and insects like grasshoppers, locusts, caterpillars, and termites, centipede, etc. are the primary consumers in this region. These primary consumers consume producers for their body’s energy needs.

Various types of grasses are present in the grassland. Herbivores present in that region such as cows, goats, rabbits are taking grass as food. In this way, the energy is transferred from the producer to the body of the primary consumer (1) & (4).

3. Secondary consumers or grazers

Consumers who take the primary consumers as food and get nutrients in their bodies are called secondary consumers or carnivorous. This type of consumer gains their body strength by eating primary eaters of a grassland. Secondary consumers take 1% of the energy of producers. The amount of biomass is medium in secondary consumers. They eat complex food.

• Example of secondary consumer

Snakes, foxes, jackals, lizards, golden eagles, coyotes, etc. are the secondary consumers of the grassland regions. These animals help fertilize grassland regions by returning nutrients to the soil through their manure.

Sometimes mammals like squirrels, rabbits are also included in the secondary consumers. All the animals are together to help shape the grassland (1) & (6).

4. Tertiary consumers or predators

Tertiary consumers are the Eaters in this region that survive by eating plants and other animals. They eat the secondary consumer. Tertiary consumers are mainly omnivorous. But sometimes they are carnivorous. These animals are also known as apex predators.  They have taken only 0.1% of energy from producers.

• Example of predators

Hawks, owls, bobcats, coyotes, wolves, etc. are the tertiary consumers of a grassland. Sometimes foxes are included as tertiary consumers in grassland. These animals help to prevent the overpopulation of prey populations. They all play a great role in the formation of grassland regions (5).

5. Decomposer

They are also the biotic factors that decompose dead plants and consumers into simple chemicals. There are various types of decomposers found in this region. These are Aspergillus, Cladosporium, Rhizopus, Penicillium, and Mucor, etc. Dead plants and the consumer’s body are decomposed by the actinomycetes, and some aerobic and anaerobic bacteria are present in this region (5).

Grassland plants and animals

Grassland can be seen in some parts of the world. These regions are located in the interior of the continent. All over the world, grasslands are known by different names and have different type’s flora and fauna. The following are some of the groups of flora and fauna based on the region.

Some plant groups of grassland by region

1. Steppe region in Eurasia

Depending on the amount of rainfall in the steppe region, different types of trees can be seen. Plants like maple, oak, willow, aspen, etc. are found in areas with rainfall of 500 to 600 mm. Fescues grasses, feather grasses grow in areas with a rainfall of 400 to 500 mm.

2. Pampas region in Argentina

The eastern part of Argentina receives 900 mm of rainfall and the western part receives 450 mm of rainfall. So the grass species of this region are the main plants. The grass species seen here are- briza, bromus, panicum, paspalum, lolium etc.

3. Downs in Australia

The main grasses of this region are- poa, tussock, and Australian themeda, danthonia pallida, stipa, aristida, mulga, etc.

4. Veld in South Africa

Here the amount of rainfall is 650 to 750 mm. Red grass, aristida, eragrostis, hyparrhenia, themeda grass, bromus, Fescues grass etc. are seen in this region (6).

Some animal groups of grassland by region

1. Steppe region in Eurasia

Mongolian gazelle, wild horse, rats with sharp teeth, wolves, eagles, hawks, polar cats, deer, etc. are the animal group present in the steppe region in Eurasia.

2. Prairies in North America

Bison, deer with thorny horns, rattlesnake, eagles, hawks, and foxes are some animals present in this region.

3. Pampas in Argentina

Pampas’ deer, Patagonian mara, viscacha, rhea birds, etc. are the main animal groups. However, in some places, swans, ducks, etc. can be seen in pampas (6).

Written By: Manisha Bharati

References

1. B Agarwal and V. K. Agarwal. Unified Botany, B.Sc. second Year. Shiva Lal Agarwal & Company Publications, Indore. Chapter: Ecosystem. Page no- 253 to 279.
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3. Hema Batra and Pridhi Bhatia. All in one, Biology, CBSE Class XII. Arihant Prakashan. Chapter: Ecosystem. Page No: 347 to 370.