Sample Location

You're planning a field investigation. You've got your equipment and done your research, so now it's time to decide where you will be sampling the natural environment. Can you imagine trying to count all the plants in a habitat? Thankfully, sampling makes this easier. Instead of counting every single plant, you take a representative sample of the population, which accurately displays the variety of species present.

Sample Location: Meaning

Before we begin, let's recap sampling. Get ready for plenty of definitions!

The aim of sampling is to select a sample that is representative of the population.

Now that we've recapped sampling, the concept of sample location is straightforward. It's the place that an environmental sample was obtained.

Importance of Sample Location

Good environmental samples should be representative and unbiased.

It's essential for scientists to avoid bias during their research. Otherwise, their data may not be objective or reliable. All scientific work is peer-reviewed to check for bias and other mistakes.

During your A-Levels, you will carry out environmental sampling. How you choose your sampling location is important. Your samples should be representative of the population and unbiased.

Types of Sample Location

There are two types of technique used to determine sampling location: random and systematic.

In random sampling, every member of the population is equally likely to be included in a sample. Random sample sites can be determined using a number generator, for example.

In systematic sampling, samples are taken at fixed, regular intervals. Typically, the area of study is divided into a grid and samples are taken in a regular pattern.

Let's compare the two types of sampling technique.

• Systematic sampling is easier and quicker to execute than random sampling. However, it will produce skewed results if the data set exhibits patterns.

• Random sampling is more difficult to execute, so it is best suited for smaller data sets. It's also likely to produce more representative results.

Transects for Environmental Gradients

Transects are a tool used for systematic sampling in a study site that experiences an environmental gradient.

A transect is a line placed across a habitat. It can be as simple as a piece of spring.

There are two kinds of transects: line and belt.

• Line transects are one-dimensional transects. Every individual who touches the line is identified and counted.

• Belt transects use a rectangular area instead of a line. They supply more data than a line transect, but are more time-consuming to use.

Either kind of transect can be continuous or interrupted.

• Continuous transects record every individual that touches the transect. They provide a high level of detail, but are very time-consuming to use. As a result, they're only suitable for short distances.

• Interrupted transects record individuals at regular intervals. Using an interrupted transect is much quicker, but doesn't provide as much detail as a continuous transect.

Characteristics of Sample Locations

Apart from sampling technique, what other factors need to be considered when choosing sample locations?

Good sample locations need to be accessible (able to be reached or entered). When choosing sample locations, avoid private land and be aware of geographical constraints, such as vertical drops or roads passing through the study site.

Fig. 2 - Common land or school property is accessible for sampling. Unsplash

It's also important to consider safety when choosing sample locations. Some methods of minimising risk when sampling include:

• Avoiding sampling in or near deep water.

• Being aware of your surroundings at all times.

• Staying in groups.

• Avoiding sampling during adverse weather conditions.

• Wearing suitable clothing and footwear.

Describing Sample Locations

There are two methods of describing a sample location: relative and absolute.

Relative Location

For example, the Angel of the North is 392 kilometres northwest of the Tower of London. It's also 16 kilometres southwest of Newcastle International Airport.

Relative location can help analyse how two places are connected by distance, culture, or biodiversity.

Absolute Location

Usually, absolute location is given in terms of latitude and longitude.

For example, the absolute location of the Angel of the North is 54.9141° N, 1.5895° W.

Examples of Sample Locations

You will carry out environmental sampling during your A-Level course. You need to be aware of suitability, accessibility, and safety before selecting sample locations.

Are the following locations suitable for your A-Level sampling?

Location 1: School Playing Field

Location 2: Shallow Rock Pool

Location 3: Open Ocean

Location 4: Private Garden

Location 5: Local Woodland

Location 6: Canadian Forest

Location 7: Motorway

Location 8: Park

Answers

1. ✔ Suitable for sampling

2. ✔ Suitable for sampling

3. ✖ Not suitable for sampling – accessibility and safety concerns

4. ✖ Not suitable for sampling – accessibility concerns

5. ✔ Suitable for sampling

6. ✖ Not suitable for sampling – accessibility concerns

7. ✖ Not suitable for sampling – safety concerns

8. ✔ Suitable for sampling

I hope that this article has explained sample location to you. Sample location is the place that an environmental sample was obtained. Sampling techniques, such as random and systematic sampling, make sure that your sample location is unbiased and representative of the population. Furthermore, sample locations should be accessible and safe.

^{1. Free Map Tool, Map Showing the Distance Between Angel Of The North, Durham Road and Newcastle International Airport, UK, 2022}

^{2. Free Map Tool, Map Showing the Distance Between Angel Of The North, Durham Road and Tower of London, London, 2022}

^{3. Google Maps, Angel of the North, 2022}