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Ecology Field Trip

Observation and Scientific Study of a Selected Ecosystem

Student Name:

This field trip will give you the chance to explore different habitats such as grassland, wood-land and freshwater systems. You will have the opportunity to sample the types of flora and fauna available in these habitats by using various apparatus to collect species and then iden-tify them using a simple key.

You will look at both the abiotic factors, such as temperature, light intensity and soil pH, as well as biotic factors, such as species interactions (competition, predation) within the habi-tats.

By the end of this field trip you should be able to:

Identify a variety of habitats within the ecosystem

Identify 5 fauna and 5 flora using simple keys

Use various apparatus required for collection of species

Conduct a quantitative study of plants and animals and know the difference be-tween quantitative and qualitative surveys

Understand the difference between abiotic and biotic factors that influence an ecosystem

Identify adaptations of different species and understand its purpose

Construct food webs and a pyramid of numbers based on field study

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Site Description

Site Map/Sketch

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Activity 1: Animal Collection and Identification

There are different methods of collecting specimens depending on the type of habitat you are sampling. Use a variety of sampling methods and record your findings.

Apparatus that you will use:

Pooter Beating Tray

Pitfall Trap Sweep Net

Cryptozoic Trap Small Mammal Trap

Choose 3 pieces of equipment and fill out the boxes below:

Collection Apparatus Used

Name: Diagram

How was it used

Type of organism collected

Name: Diagram

How was it used

Type of organism collected

Name: Diagram

How was it used

Type of organism collected

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You will use a biological key to identify the species caught. Identify the organism and note any adaptations it has to help it survive in its particular habitat. Remember to return all organisms to where you found them when you are done!

(a) Organism (Fauna) Adaptation Sketch

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(a) Organism (Flora) Adaptation Sketch

Why are structural, competitive or behavioural adaptations by organisms necessary?

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Capture-Recapture Method

This method involves collecting a number of animals of the same species. The species are then marked in some way that will not endanger them or inhibit their behaviour, for exam-ple marking snail shells with white paint will make them more visible to birds and so they will be easier prey! After marking the animals they should be released as close as possible to the capture site. After a set period of time (preferably days) a second animal collection is carried out in the same habitat. The number of marked individuals caught on the second visit should be noted. The following formula gives an approximation of the total population of that animal in that habitat.

Example:

# animals caught and marked on 1st visit = 20

# animals caught on 2nd visit = 15

# marked animals caught on second visit = 5

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Activity 2: Plant Study

Part 1. – Random Sampling: Using a quadrat

(i) Percent Frequency

In this exercise you will investigate the percent frequency of a plant. This is a qualitative sur-vey, meaning it tells you if a plant species is present or absent. This method gives you an idea of the variety of species in a habitat.

For this exercise you must identify and record a minimum of 5 plants and record and adap-tations present.

A small object will be thrown at random behind the students back and then a quadrat will be placed on top of the pen. If a species is present it is noted by a tick, if it is absent it is marked by an x. This is repeated 10 times. The number of quadrats a species shows up in is multiplied by the total number of quadrats thrown to get the percent frequency. For exam-ple if 10 quadrats are thrown and daisies are found in 7 quadrats then the total percent fre-quency of daisies in that habitat is 70%. An example of what your table should look like is given below:

Carry out the above exercise and record your data in the table below:

Plant Quadrat Number Total %

Frequency

1 2 3 4 5 6 7 8 9 10

(ii) Percent cover

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In this exercise you will investigate the percent cover of a plant. For this activity you will use a quadrat with a grid. The grid has horizontal and vertical lines, where these lines cross each other (in other words where they intersect) is a “hit point”. If a species is found under a hit point it is recorded as a “hit”. If the quadrat is 5x5 it has 25 squares and so the maximum number of hits a species may have in one quadrat is 25. Throw the quadrat 10 times and record your results in the table.

Next you must calculate the percentage cover of each species. If Daisy was hit 196 times over the 10 quadrats you would calculate as follows:

1. Total number of hits = 196

2. Total number of possible hits = 25x10 = 250

3. Divide total hits by possible hits = 196/250 = 0.784

4. Multiply by 100 to get percentage cover = 0.784 x 100 = 78.4%

Carry out the above exercise and record your data in the table below:

Plant Quadrat Number Total Hits %

Cover

1 2 3 4 5 6 7 8 9 10

Part 2. – Non-Random Sampling: Using a line transect

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For this activity you will use a rope marked at every metre. This will allow you to see the change in vegetation over a length of space within a habitat. There are 10 sampling points on the line transect with a grid quadrat at each metre mark.

At each metre mark you will measure the following abiotic factors; light intensity = light me-ter, humidity = hygrometer, air temperature = thermometer, soil temperature = soil ther-mometer, soil pH = soil pH probe. You will also record which plant species are present and give an estimate of what percent-age of the quadrat they take up.

You will work in pairs. Each pair will work at each metre mark and collate the results when you return to your school.

Transect Line and Metre Mark: _____________________

Abiotic Factor Equipment used Result

(include units)

Light Intensity

Humidity

Air Temperature

Soil Temperature

Soil pH

Plant Species Found:

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Activity 3: Food Webs, Chains and Pyramid of Numbers

Part 1 - Food Chains

Using the species identified earlier and habitats investigated, identify the role of different organisms in the pathways of energy flow.

Food Chain 1

Food Chain 2

Part 2 - Food Webs

Each plant and animal you have seen today is part of a food chain. All food chains within an ecosystem are connected because many organisms eat the same things or are eaten by the same things.

List all of the plants and animals that you have discussed today and make a food web by drawing arrows and linking them all together.

Decomposers

Primary Producers

Herbivores

Omnivores

Carnivores

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Food Web

Pyramid of Numbers

Analysis and Assessment of Results

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1. Possible sources of Error during the Field Trip

2. Relevance of reports in everyday life e.g. Environmental Impact Assessment

3. Links to other areas of syllabus