4.2- Sampling plants

Question 1

How preparation is carried put for field work?

Answer 1

1. Suitable clothing- this will depend upon the type of habitat and the expected weather conditions
2. Suitable footwear
3. Apparatus needed to carry out the sampling
4. Clipboard, pen and paper to record your observations
5. Appropriate keys to identify plans
6. Camera or smartphone to record specimens and grid location
7. Ideally, you will have considered the number of samples that you will collect and you will have prepared a result table ready to record your observation

Question 2

How can plants be identified?

Answer 2

By using a dichotomous key.

Question 3

What do you do when you visit the site for sampling plants?

Answer 3

When visiting a site to measure its biodiversity, it may be best to use a range of techniques. Random sampling is important, but it may be helpful to modify the sampling technique of the habitat is not homogeneous (even). Moving some of the sample sites into areas that look different would be classed as opportunistic sampling (as you are making decisions during the sampling process) and also stratified sampling (as you are treating parts of the habitat differently). It may also be helpful to combine random sampling with systematic sampling

Question 4

What is an important aspect to consider?

Answer 4

The effect your presence will have on the habitat. Any sampling should cause little disturbance as possible. Trampling, picking flowers placing quadrats will cause some disturbance

Question 5

Why is it best to calculate the value of percentage ground cover?

Answer 5

Large plants such as trees in a wood or field can be identified and counted individually. However many plants too small or too numerous. In this case it may be best to calculate a value of percentage ground cover occupied by each species

Question 6

What is a quadrat?

Answer 6

A quadrat is a square frame used to define the size of the sample area. A quadrat is often measured to 50cm.

Question 7

How can you use random sampling?

Answer 7

For random sampling you can generate random numbers and then use these numbers as coordinates to place the quadrat within the habitat. A tape measure will help placing the quadrat accurately.

Question 8

What do you need to do inside the quadrat?

Answer 8

• Identify the plants found

- Then calculate the percentage cover

Question 9

How can the quadrat grid help make the estimate more accurate?

Answer 9

Some quadrats have grid of string that divides the quadrat into a number of smaller squares. This makes it easier to identify species.

Question 10

How can you measure percentage cover?

Answer 10

You can measure percentage cover using a point frame. This is a frame holding a number of long needles or pointers.

Question 11

How do you use a point frame?

Answer 11

You lower the frame into the quadrat and record any plants touching the needle. If the frame has 10 needles and is used 10 times in the quadrat you will have 100 readings. So each plant touching the needle will have a 1% cover.

Question 12

What is a transect?

Answer 12

A transect is a line taken across the habitat. You stretch a long string or tape measure across the habitat and take samples along the line.
In large habitats you may use a line transect/ you’d record the plants touching the line at set intervals.

Question 13

What is an interrupted belt transect?

Answer 13

When a quadrat is used at set intervals along the line. This will provide quantitative data at intervals across the habitat.

Question 14

What is a continuous belt transecting?

Answer 14

You place a quadrat beside the line and move it along the line so you can study a band or belt in detail. This wills provide quantitative data in a band or belt across the habitat.

Question 15

What do we have to consider when measuring biodiversity?

Answer 15

Species richness

Species evenness

Question 16

What is species richness?

Answer 16

The number of species found in a habitat. The more species present the richer the habitat

Question 17

What is species evenness?

Answer 17

The measure of the relative number or abundance of individuals in each species. It is a measure of how many different species are present.

Question 18

How can species richness be measured?

Answer 18

By counting all the species present in the habitat

Question 19

How can you measure species evenness?

Answer 19

It’s more difficult to measure species evenness as you need to carry out a quantities survey.

Question 20

How would you measure the frequency of plants?

Answer 20

First use a sampling technique to take your sample. Record the percentage cover of each plant species. With large plants it is better to count the number of individuals per unit area.

Question 21

How would you measure the density of animals in a habitat?

Answer 21

This means calculating how many animals of each species there are per unit area of a habitat. Larger animals can be counted by observation and smaller ones can be counted by using sampling techniques. The population size of smaller animals can be calculated using the mark and recapture technique, but this will not work for the numerous tiny animals living in the soil. . Here the only way to estimate population size is to take a sample of soil and sift through it to find all the individuals and count them.

Question 22

How can you measure the density of animals in water?

Answer 22

Sampling in water is a similar process you can use a net to sample in the body of the water and to sift through the mud at the bottom. Then you can estimate the population size and density.