Ecology and Environmental Cycles

Abiotic factors

Non-living physical and chemical components of an ecosystem

Biotic factors

Living components of an ecosystem

Quadrat sampling method Purpose

Used to estimate the population density of slow-moving or stationary organisms like plants or barnacles.

How to do Quadrat Sampling method

Place a square frame of known size randomly in a habitat, count the organisms, repeat several times, and calculate the average.

Transect Sampling Method Purpose

Used to study the distribution and abundance of organisms or other variables along a specific line or path, allowing researchers to see how they change in relation to distance and environmental factors.

How to do Transect method

Lay a straight line (tape or rope) across a habitat and record organisms along it or at regular intervals using quadrats.

Capture-Recapture method Purpose

Used to estimate the population size of animals (e.g., fish, birds, mice).

How to do Capture-recapture

Capture a sample, mark, count, and release it. After some time, recapture another sample. Repeat. Estimate the total population by comparing marked to unmarked animals.

Photosynthesis

The process by where producers (plants) use water and carbon dioxide, along with sunlight, to produce glucose and oxygen.

Word equation for photosynthesis

Carbon dioxide + Water + Sunlight → Glucose + Oxygen

Cellular respiration

The process that occurs in all living cells to release energy (ATP) from glucose.

Word equation for cellular respiration

Glucose + Oxygen → Carbon dioxide + Water + Energy

Chlorophyll

It's a green pigment in chloroplasts that absorbs sunlight to power photosynthesis.

Food chain

A simple pathway showing how energy flows from one organism to another.

Food web

A network of many interconnected food chains in an ecosystem.

Producer

An organism that makes its own food using sunlight (e.g., grass, algae).

1st order (primary) consumer

An organism that eats producers (herbivore).

2nd order (secondary) consumer

An organism that eats primary consumers.

food chain arrows

The direction of energy flow — from the eaten to the eater.

water cycle

How water is recycled through evaporation, condensation, transpiration, percolation, and precipitation.

human impact on the water cycle

Water pollution from industrial waste, sewage, and pesticides.

carbon cycle

How carbon moves between the atmosphere, organisms, and the Earth (via photosynthesis, respiration, and burning fossil fuels).

human impact on the carbon cycle

Burning fossil fuels and deforestation release excess CO₂, contributing to global warming.

nitrogen cycle

How nitrogen moves through the atmosphere, soil, water, and living things.

human impact on the nitrogen cycle

Excess fertilizer adds too much nitrogen, causing water pollution (eutrophication) and air pollution.

back burning in Indigenous land management

Controlled fires that remove undergrowth, reduce wildfire risk, and promote new plant growth for food and habitat.

natural fencing in Indigenous land management

Using logs and branches to guide animals like kangaroos for hunting and to prevent overuse of land.

fish traps in Indigenous land management

Stone traps that catch fish as the tide goes out while allowing smaller fish to escape, keeping populations sustainable.

ways to reduce landfill waste

Recycling, composting, reducing single-use plastics, and education programs about waste separation.

creative waste management solutions

Turning food waste into biogas or fertilizer, using plastic waste in road construction, and upcycling rubbish into furniture or building materials.