Food Chain of Herbivory and Carnivory

 Key Concepts

• Food chain
• Producers
• Consumers
• Decomposers
• Carnivory
• Herbivory

Introduction: 

An ecosystem comprises the biotic and abiotic factors of a particular environment. Organisms that live together in an ecosystem interact with other living organisms and also with non-living factors. These interactions are mainly done to find food, water, space, mates, etc. However, the energy requirement is the driving force of these interactions. 

Explanation: 

Sun is the ultimate source of energy: 

All organisms need energy to grow and survive. This energy is obtained from food that contains the necessary nutrients required for growth. Different organisms eat different types of food and have different methods to obtain that food. For example, black-tailed prairie dogs living in the grasslands of North America eat grass and seeds to get the energy they need. 

The energy required for most life on Earth comes from the Sun. Some organisms use the Sun’s energy to create energy-rich molecules by the process of photosynthesis. The energy-rich molecules consist mainly of sugars and serve as food. Energy moves from one organism to another when one organism consumes the other. The path that the energy takes may be short and simple or long and complicated. 

Food chain: 

A food chain is a model that helps us to understand how energy moves in an ecosystem. It shows how each organism in a community gets its food. 

For example, in this food chain, the plants are producers, and the animals that follow are consumers. Energy moves from the plant to the owl. 

Organisms in every community are divided into three groups depending on their functions in that community. These groups throw light on how organisms get the nutrients and energy that they need. The three groups are as follows: 

1. Producers 

2. Consumers 

3. Decomposers  

Producers: 

Organisms that use an external energy source like the Sun to make energy-rich molecules are called producers. They convert the energy of the sun into chemical energy or food. Most producers are green plants and contain chlorophyll, a chemical that is required for photosynthesis. Producers use some of the food prepared by them and store the rest. 

Plants may store food in various parts like leaves, stems, or roots. When other organisms eat plants, they obtain energy from the food that the plants have made and stored. Plants are the major producers on land, whereas in the ocean majority of producers are phytoplankton. 

Some producers like certain types of bacteria, do not contain chlorophyll and do not use energy from the Sun. These bacteria use chemicals instead of sunlight as an energy source to make food. This process is called chemosynthesis. These organisms can be found near the volcanic vents on the ocean floor. 

Consumers: 

Every organism on the Earth cannot make its own food like producers. Organisms that cannot make their own food are called consumers. They obtain energy and nutrients by eating other organisms. They are mainly dependent on the producers. They help in maintaining the size of the population of any species in an ecosystem. There are several kinds of consumers. 

Consumers can be divided into three groups: 

• Herbivores 
• Carnivores 
• Omnivores 

Herbivores: 

A consumer that only eats plants is known as a herbivore. They are the vegetarians of the world. They include rabbits, deer, and other plant-eaters. They can feed on all plant parts like leaves, stem, tubers, fruits, seeds, etc. 

Carnivores: 

A consumer that only eats other animals is known as a carnivore. They can be as large as a lion or as small as a frog. 

Examples of carnivores include frogs, spiders, sharks, owls, etc. 

Omnivores: 

A consumer that eats both plants and animals are called omnivores. Humans are also omnivores as they mostly eat plants and animals. Other examples of omnivores include pigs, racoons, grasshopper mice, etc. Scavengers are also omnivores since they feed on dead animal and plant matter. 

Decomposers: 

Organisms that obtain energy and nutrients from dead organisms are called decomposers. Decomposers include fungi, bacteria, and earthworms which consume wastes and dead organisms. They help recycle once-living matter by breaking it down into simple, energy-rich substances. As a result, decomposers play a very important role in any ecosystem. 

Predator-prey interaction: 

We have already learned that predation is a type of interaction in which one animal kills the other animal in order to obtain energy. The organism that kills and feeds on the other organism is called the predator, whereas the organism that gets killed is called the prey. This interaction is beneficial for the predator, but it is harmful to the prey. Predation plays an important role in maintaining the population size in different communities, which also promotes biodiversity. 

Both the prey and the predators have various adaptations that help them carry out their functions in the ecosystem. The predators have a heightened sense of smell or sight, the ability to run, hunt in groups, etc. Similarly, the prey also has adaptations like camouflage or mimicry that protects it from the predator. 

Food chain and predation: 

Ultimately, the main source of energy for all life forms originates from the sun. Plants use the sun’s energy, animals consume plants and use the plants’ energy, and some animals consume other animals and use their energy. The food chain is like a cycle of predation, and although it is necessary for life to exist, it has to have limits. The balance between the survival of prey and predator is part of the reason that our ecosystem is so diverse. 

Carnivory as a type of predation: 

Carnivory is the first thing that comes to mind while thinking of predation. It is the most common type of predation where the predator kills the prey and feeds on its flesh. The predators are often large animals like a tiger, shark, lion and wolf, which feeds on smaller animals like rabbits and deer. 

Carnivorous predation can also be observed in the plant kingdom, among insectivores such as pitcher plants and Venus flytraps. Insectivores are mostly found in regions where the soil is not rich in nutrients. Another exceptional and unusual form of carnivorous predation is cannibalism, where individuals consume members of their own species. 

Herbivory as a type of predation: 

Herbivory is also a type of predation where the predators feed on autotrophs like plants and algae. Herbivores control the number of producers in the ecosystem. It is not usually considered a type of predation. Similar to carnivorous predations, the predators and prey in herbivorous interaction also develop different forms of adaptation. Consider the example of giraffe and acacia tree. The giraffe has a long neck that helps it feed on leaves at a height. 

The prey plants like acacia also develop defense mechanisms like the release of toxic substances in their leaves and ethylene gas which signals the surrounding trees to produce the toxin. 

Summary

• Organisms that live together in an ecosystem interact with other living organisms and also with non-living factors. These interactions are mainly done to find food, water, space, mates, etc.
• All organisms need energy to grow and survive, and the energy is obtained from food.
• Different organisms eat different types of food and have different methods to obtain that food.
• Sun is the ultimate source from where all organisms obtain energy.
• Some organisms use the Sun’s energy to create energy-rich molecules by the process of photosynthesis.
• A food chain is a model that helps us to understand how energy moves in an ecosystem.
• Organisms in every community are divided into three groups depending on their functions in that community. They are as follows:
• 1. Producers
• 2. Consumers
• 3. Decomposers
• Organisms that use an external energy source like the Sun to make energy-rich molecules are called producers. They convert the energy of the sun into chemical energy or food.
• Some bacteria use chemicals instead of sunlight as an energy source to make food. This process is called chemosynthesis.
• Organisms that cannot make their own food are called consumers. Consumers are of three types:
• 1. Herbivores: only eat plants
• 2. Carnivores: only eat other animals
• 3. Omnivores: eat both plants and animals
• Organisms that obtain energy and nutrients from dead organisms are called decomposers.
• Carnivory is the most common type of predation where the predator kills the prey and feeds on its flesh.
• The predators are often large animals like a tiger, shark, lion and wolf, which feeds on smaller animals like rabbits and deer.
• Herbivory is also a type of predation where the predators feed on autotrophs like plants and algae.