Ecology – SSC JE Study Notes
Subject – General Awareness & Current Affairs
Exam – SSC Junior Engineer (JE)
These notes are crafted to help you grasp the core concepts of ecology, remember the most important facts, and quickly revise them before the exam.
1. Simple Explanation
Ecology is the science that studies living organisms and their interactions with each other and their environment.
- Organisms: Plants, animals, fungi, bacteria, and other microbes.
- Environment (Abiotic factors): Sunlight, temperature, water, soil, air, and nutrients.
- Key Focus: How energy and matter cycle through ecosystems, how species adapt, and how human activities affect the balance of nature.
2. Key Points
| # | Concept | Important Details |
|---|---|---|
| 1 | Definition | Ecology = “study of relationships between organisms and their environment.” |
| 2 | Ecosystem | A community of organisms plus the physical environment they inhabit. |
| 3 | Biotic vs. Abiotic | Biotic – living parts (plants, animals). Abiotic – non‑living parts (water, soil, temperature). |
| 4 | Trophic Levels | 1) Producers (autotrophs) → 2) Primary consumers → 3) Secondary consumers → 4) Tertiary consumers → 5) Decomposers. |
| 5 | Energy Flow | Food chain → Food web → Biomass → Energy pyramid (only ~10% energy transfers). |
| 6 | Biodiversity | 1) Species diversity (variety of species) 2) Genetic diversity (variations within species) 3) Ecosystem diversity (different habitats). |
| 7 | Keystone Species | Species whose impact on an ecosystem is disproportionately large relative to their abundance (e.g., sea otters). |
| 8 | Human Impact | 1) Deforestation, 2) Pollution, 3) Over‑fishing, 4) Climate change, 5) Urbanization. |
| 9 | Conservation Strategies | 1) Protected areas (national parks, wildlife sanctuaries) 2) Legal measures (Wildlife Protection Act, CITES) 3) Sustainable practices (afforestation, eco‑tourism). |
| 10 | Ecological Footprint | The amount of natural resources an individual or community consumes per year compared to the planet’s ability to regenerate those resources. |
| 11 | Carrying Capacity | The maximum population size of a species that an environment can sustain indefinitely. |
| 12 | Current Affairs (2024) | - UN Biodiversity Conference (COP15): Target 30% of oceans protected by 2030. - National Biodiversity Action Plan 2024: 15% of India’s land area to be protected. - India’s “Green India” Initiative: 2.5 billion trees by 2030. - Climate‑Proofing of agriculture: 40% of farms adopting climate‑resilient crops. |
3. Worked Example
Problem
A small town of 100,000 people consumes the equivalent of 1.2 m² of forest area per person for timber, food, and fuel. The global average ecological footprint is 1.5 m² per person.
Question
- What is the total ecological footprint of the town?
- How many more people would the town need to meet the global average ecological footprint?
Solution
-
Total footprint of town
[ \text{Footprint}_{\text{town}} = \text{Population} \times \text{Footprint per person} ] [ = 100{,}000 \times 1.2 \text{ m}^2 = 120{,}000 \text{ m}^2 ] -
Footprint if it matched the global average
[ \text{Desired footprint} = 100{,}000 \times 1.5 = 150{,}000 \text{ m}^2 ] -
Additional footprint required
[ \Delta = 150{,}000 - 120{,}000 = 30{,}000 \text{ m}^2 ] -
Number of additional people
[ \text{People}_{\text{add}} = \frac{\Delta}{\text{Footprint per person}} = \frac{30{,}000}{1.2} = 25{,}000 ]
Answer
- Total ecological footprint of the town: 120 000 m².
- To reach the global average of 1.5 m² per person, the town would need 25 000 more people (or a reduction in per