Fieldwork techniques

Fieldwork activities and techniques to investigate PCW

During fieldwork to investigate Porters Creek Wetland as an Ecosystem at Risk there are a variety of techniques you can use to gather fieldwork data . It is possible during fieldwork to investigate many sections of the syllabus for this topic by

measuring and recording features of the biophysical environment (abiotic and biotic) to understand important biphysical interactions and ecosystem functioning.
recording evidence of natural stresses and human modifications
observing and recording management strategies and identifying evidence of effectiveness

Measuring biotic and abiotic features

a. Hydrosphere

Water samples are needed to test for water quality.

Use a turbidity tube to measure water clarity / suspended sediment.

Undertake a water bug survey to assess water quality. The presence of species vulnerable to pollution will indicate good water quality or these species would not survive.

Measure the pH of the water using chemical test and salinity using a spectrometer.

Measure water temperature - temperature affects oxygen content and ability to support aquatic life.

THINK: What do the test results tell you about the hydrosphere in the wetland?

Collect water samples

Using a turbidity tube

Water bug survey

b. Atmosphere

Climate and weather impact on wetlands. Climate will determine average annual precipitation and average yearly temperatures - influencing wetland hydrology and biodiversity. Extreme weather events cause drought, flood and bushfires in PCW.

During fieldwork weather conditions can be measured and compared to typical conditions for that season. The impact of climate change on weather can be discussed.

Use a Kestral and light meter to measure atmospheric conditions on the day you visit.

THINK: What do the measurements tell you about atmospheric conditions in the wetland? Are these average conditions for the time of year of your visit?

How might these conditions change seasonally and from year to year?

What impact might anthropogenic climate change have?

How to Use a Kestral 3000You Tube Rumbalara EEC (46 seconds) Transcript

How to Use a Light MeterYou Tube Rumbalara EEC (41 seconds) Transcript

c. Lithosphere

Freshwater wetlands form in a shallow basin where water drains and collects. Use a clinometer to meaure the slope / gradient of the land to determine the direction and speed of water flow into the wetland. A Dumpy Level could also be used.

Soil influences biodiversity. Soil type, texture and pH are important to species that live in a wetland and the ability of a wetland to retain water. Sediment is deposited by runoff. Loams have a high % of silt and clay (less sand) and retain water - an important feature for water loving plants. Soil pH influences plant species.

Conduct tests to determine soil pH, temperature, soil type and structure.

THINK: Can you describe the features of the lithosphere in PCW using your test results?

How important is the lithosphere to the functioning of the PCW ecosystem?

What is soil?You Tube Rumbalara EEC (28 seconds) Transcript

How to test soil pHYou Tube Rumbalara EEC (47 seconds) Transcript

Soil TextureYou Tube Rumbalara EEC (37 seconds) Transcript

How to use a clinometerYou Tube Rumbalara EEC (21 seconds) Transcript

Soil Ph

Soil structure

Soil temperature

d. Biosphere

There is a high biodiversity of plants and animals in the wetland.

Observe different plants including nine different paperbarks, Swamp Mahogany, Wollybutts, sedges and reeds and their adaptations to living in the wetland. Identify plants using images.

Investigate species density and distribution using quadrats and transects.

Classify foilage cover and calculate canopy cover using a Specht Chart.

How did you classify the plant community you visited?

Why are the plants you identified found at the site you visited?

Comment on the diversity of plant species at the site you visited.

How important is biodivserity for the resilience of PCW?

Measuring distribution and abundanceYou Tube Rumbalara EEC (43 seconds) Transcript

Use a quadrat to investigate species density and distribution

Use a specht classification chart (below) to identify features of a plant community.

Identify common plants at and near the billabong

Specht Chart - plant communities

Specht Chart - canopy cover

Use a plant identification chart at the site(s) you visit.

Paperbark

Melaleuca species

Wollybutt

Eucalyptus Logifolia

Swamp Mahogany

Eucalyptus Robusta

Sedges

Reeds

Grass Tree

Xanthorea

Rushes -Lomandra

Wattle

Acacia species

2. Observing and recording

In addition to collecting data it is important to observe the total environment - physical and human features. The data collected about the biophysical environment will provide evidence about the features and functioning of the environment as well its as the physical health at that point in time. The extent and impact of human activitiy and management actions are made by observing and recording evidence.

3. Mapping: Pre fieldwork preparation

When visiting the wetland site locate your position on a map and remember that other locations in the wetland will be different. Maps showing vegetation communities and drainage lines, contours and settlement will assist in assessing the functioning of the wetland and pressure from human activities. Examples are shown below.