Quadrats and Transects

Flashcards covering ecological sampling techniques, including the use of quadrats, transects, cover estimation methods, random sampling, and systematic sampling.

What sampling tool can be used to sample sedentary organisms like plants?

A quadrat.

What is the most common way to estimate plant numbers when counting individual plants is not possible?

To use an estimate of cover.

How is percentage cover calculated in the first gridded quadrat method described?

By counting the number of squares that the plant appears in and taking the total to be the percentage cover.

In the gridded quadrat example where plant B appears in $11\%$ of squares and plant A appears in $14\%$, what is the percentage cover of C?

$$100 - (11 + 14) = 75\%$$

What is the alternative method of estimating percentage cover using a gridded quadrat?

Counting each square in which the plant occupies more than half of the area.

Why do the percentages ($7\%$ for B, $9\%$ for A, and $87\%$ for C) in the second gridded quadrat method not add up to $100$?

Because of the rounding effect.

What sampling strategy should be used when the aim is to compare two areas?

A random sampling strategy (placing the quadrat randomly in each area).

What sampling method should be used to see how species change along an environmental gradient?

Systematic sampling, placing the quadrat along a line called a transect.

What example of an environmental gradient is provided in the text?

The change in light intensity from the shade of a woodland into an open field.

At what intervals can a quadrat be placed along a transect line in systematic sampling?

At either regular or irregular intervals.