Keshu

What ecology focuses on

• Organisms – plants, animals, microbes

• Environment – air, water, soil, climate

• Interactions – who eats whom, competition, cooperation, and adaptation

Levels of ecological study

• Individual – how a single organism survives

• Population – members of the same species in an area

• Community – different species living together

• Ecosystem – living organisms + non-living factors

• Biome – large regions like deserts, forests, tundra

• Biosphere – all life on Earth

Key concepts

• Food chains & food webs – energy transfer

• Producers, consumers, decomposers

• Energy flow & nutrient cycles (carbon, nitrogen, water)

• Habitat & niche

• Biodiversity

• Ecological balance

🔹 Branches of Ecology

1. AutecologyStudy of a single species and its relationship with the environment.

2. SynecologyStudy of groups of species (communities) living together.

3. Population EcologyDeals with population size, density, growth, dispersion, and regulation.

4. Community EcologyFocuses on interactions like predation, competition, parasitism, mutualism.

5. Ecosystem EcologyStudies energy flow and nutrient cycling between living and non-living components.

6. Landscape EcologyExamines spatial patterns and human impact on ecosystems.

7. Global EcologyStudies biosphere-level processes like climate change.

🔹 Components of an Ecosystem

1. Abiotic (Non-living)

• Light

• Temperature

• Water

• Soil

• Air

• Minerals

2. Biotic (Living)

• Producers – Green plants, algae

• Consumers – Herbivores, carnivores, omnivores

• Decomposers – Bacteria, fungi

🔹 Energy Flow

• Energy enters as sunlight

• Flows one-way

• Follows the 10% law (only ~10% energy passes to next trophic level)

Sun → Plants → Herbivores → Carnivores → Decomposers

🔹 Biogeochemical Cycles

• Carbon Cycle

• Nitrogen Cycle

• Water Cycle

• Phosphorus Cycle

They recycle nutrients and maintain life balance.

🔹 Succession

Succession is the gradual and orderly change in the species composition of an area over time.

• Primary succession – bare land (lava, rocks)

• Secondary succession – after disturbance (fire, flood)

🔹 Human Impact on Ecology

• Deforestation

• Pollution

• Climate change

• Overpopulation

• Habitat destruction

🔹 Conservation

• Wildlife sanctuaries

• National parks

• Biosphere reserves

• Sustainable resource use

🔹 Ecological Pyramids

Ecological pyramids are graphical representations that show the relationship between organisms

Types

1. Pyramid of Numbers – shows the number of organisms at each level

2. Pyramid of Biomass – shows the total mass of organisms

3. Pyramid of Energy – shows the energy flow