Environment Components and Ecosystems

Overview

Environment Components and Ecosystems forms the foundational chapter in Environmental Studies for KAR TET Paper I. This topic establishes the basic vocabulary and conceptual framework that underlies all other EVS themes—from pollution to biodiversity to sustainable development. Examiners frequently test whether candidates can correctly classify components, identify relationships between living and non-living elements, and apply these concepts to Karnataka-specific contexts.

For the TET, you must be able to distinguish biotic from abiotic factors, explain how they interact within an ecosystem, and identify the functional roles of producers, consumers, and decomposers. Questions often present a scenario (pond, forest, grassland) and ask you to identify components or predict what happens when one element changes. Mastering this topic also strengthens your pedagogy answers, since EVS teaching emphasises connecting children to their immediate environment.

Key Concepts

• **Environment** is the sum total of all living (biotic) and non-living (abiotic) factors that surround and influence an organism. It includes physical surroundings, climate, other organisms, and human-made elements.

• **Biotic components** are all living organisms in an environment—plants, animals, microorganisms, and humans. They are classified by their nutritional role: producers, consumers (primary, secondary, tertiary), and decomposers.

• **Abiotic components** are non-living physical and chemical factors—sunlight, temperature, water, air, soil, minerals, humidity, and wind. They determine which organisms can survive in a habitat.

• **Ecosystem** is a functional unit where biotic and abiotic components interact through energy flow and nutrient cycling. Examples: pond ecosystem, forest ecosystem, grassland ecosystem, desert ecosystem.

• **Interdependence** means organisms depend on each other and on abiotic factors for survival. Plants need sunlight and water; herbivores need plants; carnivores need herbivores; decomposers recycle nutrients back to soil.

• **Habitat** is the specific place where an organism lives (e.g., a frog's habitat is a pond), while **niche** is the organism's functional role and position in the ecosystem.

• **Balance in ecosystems** is maintained when energy flows and nutrient cycles remain stable. Removal or addition of any component disturbs this balance.

Formulas / Key Facts

| Fact | Detail | |------|--------| | Two main environment components | Biotic (living) and Abiotic (non-living) | | Primary abiotic factors | Sunlight, water, air, temperature, soil, minerals | | Producer examples | Green plants, algae, phytoplankton (autotrophs) | | Primary consumer | Herbivores—eat producers (grasshopper, deer, rabbit) | | Secondary consumer | Carnivores—eat herbivores (frog, snake, small fish) | | Tertiary consumer | Top carnivores—eat secondary consumers (eagle, tiger, shark) | | Decomposers | Bacteria, fungi—break down dead matter, return nutrients to soil | | Largest ecosystem on Earth | Biosphere (entire Earth where life exists) | | Karnataka ecosystem examples | Western Ghats rainforest, Deccan plateau grassland, mangroves of Uttara Kannada |