🌍 Methods to Assess Distribution
(Distribution = Where organisms live)
To assess where different species are found in a particular area, scientists use these methods:
1. Quadrat Sampling
What is it?
Imagine dividing your garden into small square boxes (quadrats). Then, you randomly pick a few boxes and look inside each to count or note down what plants or animals are present.
Example:
In a grassland, scientists might place 1m x 1m square frames (quadrats) on the ground randomly and count how many dandelions are in each square.
Usefulness:
- Works best for plants or animals that don’t move much (e.g., snails, corals).
- Helps in estimating how common or rare a species is.
🧠 Mnemonic: “SQUARE your efforts”
To remember Quadrat = Square, think:
“To measure biodiversity, you must SQUARE your efforts.”
It reminds us that this method uses square frames.
2. Transect Sampling
What is it?
This involves drawing a straight line (called a transect) across a habitat and recording what organisms are found along that line at regular points.
Example:
At a beach, you can place a rope from the waterline to the sand dunes. Every 5 meters, you record what plants or animals are present.
Usefulness:
- Good for studying how species change across different environments, like from dry land to water.
🧠 Mnemonic: “TRAVEL the TRANSECT”
Think: “As you TRAVEL along the line, you TRANSECT nature.”
3. Aerial Surveys
What is it?
Scientists use drones or aircraft to take pictures or videos from the sky to observe animals or plants over large areas.
Example:
In Africa, drones fly over grasslands to count herds of elephants or giraffes.
Usefulness:
- Helps in monitoring large animals or hard-to-reach places like mountains or swamps.
🧠 Mnemonic: “AIR gives the EYE”
Think: “Using AIR gives us the EYE to see big areas.”