Ecology – SSC MTS (General Awareness & Current Affairs)
Ecology – The branch of biology that studies the interactions among organisms and their physical environment. It looks at how life is distributed, how organisms depend on one another, and how energy and matter cycle through ecosystems.
1. Simple Explanation
| Term | What it means | Everyday example |
|---|---|---|
| Ecosystem | A community of living things (plants, animals, microbes) plus the non‑living parts (soil, water, air) that interact as a system. | A forest, a pond, a coral reef. |
| Biotic component | The living part of an ecosystem. | Trees, insects, fish. |
| Abiotic component | The non‑living part of an ecosystem. | Sunlight, temperature, soil, water. |
| Trophic level | Rank in a food chain (producer, primary consumer, secondary consumer, …). | Grass → deer → fox. |
| Energy flow | Energy enters an ecosystem via photosynthesis and moves up the food chain; most is lost as heat. | Sunlight → plants → herbivores → carnivores. |
| Biogeochemical cycle | The movement of elements (C, N, P) through living and non‑living parts of ecosystems. | Carbon cycle: CO₂ → plant → animal → soil → CO₂ again. |
| Biodiversity | Variety of life at all levels – genes, species, ecosystems. | Coral reefs host thousands of species. |
| Endangered species | Species at risk of extinction. | Sumatran tiger, Hawksbill turtle. |
| Invasive species | Species introduced to a new area that disrupts the local ecosystem. | Kudzu in the US, Lionfish in the Atlantic. |
Bottom line – Ecology helps us understand who lives where, how they interact, and how we can keep ecosystems healthy.
2. Key Points
| # | Concept | Why it matters for SSC MTS |
|---|---|---|
| 1. Ecosystem Types | Forests, grasslands, wetlands, marine, urban, etc. | Questions often ask about which ecosystems are vulnerable or which ones are protected in India. |
| 2. Food Chain & Web | Producers → primary consumers → secondary consumers → apex predators. | Helps answer “Which species controls population?” |
| 3. Energy Pyramid | 10 % rule – only ~10 % of energy is transferred to the next trophic level. | Useful for calculating biomass or understanding biodiversity loss. |
| 4. Biogeochemical Cycles | Carbon, nitrogen, phosphorus, water cycles. | Links to climate change and anthropogenic impacts. |
| 5. Biodiversity & Conservation | Endangered species lists, IUCN Red List, Ramsar sites. | Needed for questions about conservation policies and India’s biodiversity strategy. |
| 6. Human Impact | Deforestation, pollution, over‑fishing, climate change. | Core theme in current affairs and policy questions. |
| 7. Indian Legislation | Forest Conservation Act, Wildlife (Protection) Act, Biodiversity Act, National Green Tribunal. | Questions may ask which act protects endangered species or who is the authority? |
| 8. Climate‑Related Ecological Events | Coral bleaching, monsoon variability, Amazon fires, Himalayan glacial melt. | Current affairs references – COP meetings, IPCC reports. |
3. Worked Example
Problem:
A temperate forest has the following biomass (in kg per hectare):
| Trophic level | Biomass (kg/ha) |
|---|---|
| Producers (trees) | 8 000 |
| Primary consumers (herbivores) | 800 |
| Secondary consumers (carnivores) | 80 |
| Tertiary consumers (top predators) | 8 |
- Show the energy pyramid.
- Calculate the energy transferred from producers to tertiary consumers.
- Comment on the health of the ecosystem.
Step‑by‑Step
-
Energy Pyramid
-
Producers → Primary consumers: transfer ≈ 10 %
(8{,}000 × 0.10 = 800) kg (matches given biomass) -
Primary → Secondary: 10 % of 800 = 80 kg
-
Secondary → Tertiary: 10 % of 80 = 8 kg
-
-
Energy Transferred
From producers to tertiary = 8 kg/ha.
This is only 0.1 % of the primary biomass – a normal result of the 10 % rule. -
Health Check
- Balanced pyramid – each level is roughly 10 % of the previous one → stable ecosystem.
- High producer biomass – indicates good forest cover.
- Low apex biomass – normal; apex predators are few due to their high trophic level.
Takeaway: A healthy, balanced ecosystem follows the 10 % rule; deviations may signal imbalance or human disturbance.
4. Current Affairs (Jan 2025 – Nov 2025)
| Date | Event | Relevance |
|---|---|---|
| Jan 2025 | UN COP25 in Nairobi: Focus on adapting to climate change in vulnerable ecosystems. | Shows global policy |