Ecosystem - Structure and Function of an Ecosystem

These are the non-living components of the ecosystem that support life. They can be divided into:

1. Physical Factors

It includes air, water, vapours, minerals, soil, and sunlight. These are essential for providing the basic conditions required for the survival of living organisms.

For example,

• Sunlight is the source of energy for photosynthesis.
• Water is vital for all life processes.

2. Chemical Factors

It include,

• Inorganic Substances such as hydrogen, oxygen, nitrogen, calcium, iron, potassium, and sodium. These are basic elements required for the growth of plants and animals.
• Organic substances such as carbohydrates, proteins, and lipids. These are formed by living organisms and serve as a source of energy and structural components for life.

These are the living organisms in the ecosystem and are divided based on their roles in the food chain:

1. Autotrophic (Producers): Producers (plants) synthesise their own food through photosynthesis using sunlight, water, and carbon dioxide. They are the primary source of energy for all other organisms.

2. Heterotrophic (Consumers): These organisms depend on producers or other organisms for food. They are further classified into:

• Primary Consumers: Herbivores like deer and rabbits, which directly feed on plants.
• Secondary Consumers: Carnivores like foxes, which feed on herbivores.
• Tertiary Consumers: Top predators like tigers, which feed on other carnivores.

3. Decomposers: Decomposers (microbes like bacteria and fungi) break down organic substances (like carbohydrates, proteins, and lipids from dead plants and animals) into inorganic substances (like hydrogen, oxygen, calcium, iron, etc.). They recycle nutrients back into the ecosystem, maintaining the nutrient cycle.

Interactions among factors of an ecosystem:

1. All living organisms rely on abiotic factors like air, water, sunlight, and nutrients for survival.
2. Different organisms have specific needs; some microbes require oxygen while others do not, and some plants thrive in sunlight while others prefer shade.
3. Abiotic factors influence which organisms can live in a particular ecosystem and their population sizes. For example, deserts with little water support only plants and animals adapted to dry conditions.
4. Abiotic factors are constantly altered by living organisms, such as plants absorbing soil nutrients and animals releasing carbon dioxide.
5. Biotic factors interact closely, with plants providing food and shelter to animals and animals assisting plants through pollination and seed dispersal.

Role of Each Organism: In an ecosystem, every living organism has a specific role, which is called its niche. This role includes everything the organism does and how it interacts with its surroundings, both living (biotic) and non-living (abiotic).

• A niche refers to an organism’s way of life in its environment.
• It includes its behaviour, diet, habitat, and interactions with other organisms and abiotic factors (like air, water, and sunlight).
• The niche ensures that every organism contributes to the ecosystem's balance.

For example,

A sunflower plant in a garden evolves oxygen in the air and provides food and shelter for insects like ants, honeybees, etc.

Ecosystems are highly complex and diverse systems where living and non-living elements interact. This complexity arises from the variety of ecosystems, the distribution of species, and the interconnected nature of these systems.

1. Variety of Ecosystems: There are many types of ecosystems, such as forests, ponds, rivers, and oceans, each with its own unique features. The characteristics of an ecosystem depend on factors like its location, climate, and the types of plants and animals living there.

For Example,

• A desert ecosystem is dry with limited water and supports plants like cacti and animals like camels, while a forest ecosystem is lush and supports a wider variety of species.

2. Species Distribution: The number and types of organisms vary between ecosystems.

• Some species, like grasses in tropical regions, are found in large numbers because the conditions favour their growth.
• Rare species, like certain endangered animals or plants, may only exist in small populations in specific areas.

3. Interconnectedness: Although ecosystems may appear independent, they are all linked to one another.

For example,

• A river ecosystem supports nearby forest ecosystems by supplying water for trees, animals, and other organisms.
• Similarly, forests contribute to the river ecosystem by preventing soil erosion and maintaining water quality.

Biomes are large ecosystems that cover extensive areas of the Earth and are characterised by similar climate conditions, plants, and animals. They are made up of many smaller ecosystems working together under the same environmental conditions.

• A biome is a large geographical area that shares a similar climate, abiotic factors (like soil, water, and temperature), and types of organisms.
• For example, a tropical forest biome is warm and wet, with plants like tall trees and animals like monkeys, while a desert biome is hot and dry, supporting cacti and animals like camels.

Biomes are not single ecosystems but are made up of many smaller ecosystems.

• For example, a tropical forest biome may include river ecosystems, canopy ecosystems, and forest floor ecosystems.
• Similarly, a desert biome may include sand dune ecosystems and oases.