Surveying the impact of weeds is fundamental to maintaining riparian health – so how do we conduct a survey? This episode takes you through the practical skills and processes of researching in the field. You will learn how to do a field sketch, a belt transect survey and a relative density survey. Now you can go out and do your own survey in your local riparian zone.

Save Our Catchment – Episode 9

WARNING – Aboriginal and Torres Strait Islander viewers are warned that the following video may contain images and voices of deceased persons.

[Screen reads – Focus question: How can data collection clarify if a species is a pest species in a particular location?]

Narrator – Data collection is important in land care management. The data provides an overview of environmental degradation over time. In this Virtual Excursion, we will be collecting data on the distribution of Cat's Claw Creeper, to see if it is indeed a pest species in a particular location.

[Screen reads – The more you repeat a relative density survey in your study area the more accurate your data will be]

Ideally, this should be repeated each year in order to compare how the Cat's Claw is progressing. Specific environmental management strategies may need to be put in place in an attempt to control the Cat's Claw population. In this episode, we're going to be learning about how to collect data in the field. Our focus for research is the abundance and distribution of the Cat's Claw Creeper. You will learn how to conduct a belt transect survey, use quadrants, calculate percentage cover, and conduct a relative density survey. You will then be able to use these skills to collect data on a particular species in an area of your choice.

[Screen reads: Distribution of species. Species distribution is the manner in which a biological taxon is spatially arranged]

The distribution of species describes where it is found. Species like the Cat's Claw are not spread evenly throughout an ecosystem. They occupy spaces that are best suited for their survival.

[Screen lists – Larger plants to adhere to, adequate water supply, rich soil types, shade]

The Cat's Claw is growing in abundance in the Upper Clarence River catchment. Abundance of a species describes how many members of a species are found throughout an ecosystem. Abundance is not the same throughout an ecosystem. Abundance will increase if the birth rate exceeds the death rate. Here, teachers will show you how to conduct a simple belt transect, and also, relative density survey. This will help you to identify the distribution and abundance of the Cat's Claw Creeper at three sites in the Upper Clarence catchment.

The first step in field work is to make some preliminary observations. Stand in the area to be surveyed, and make a simple plan drawing of its key features. You might need to note direction, which way is north, latitude and longitude, often easily found on your phones, note any nearby buildings, landforms, large plants, roads, land use, bridges, et cetera. Draw your plan view on a blank piece of paper and clearly label the plan. The more information you record will help you to remember later what you observed at each site.

To successfully calculate percentage cover, you need to be able to use a quadrant and rule out a transect. Here, teachers have measured a transect 10 metres from the river or creek up towards the tree line. This is commonly known as a simple belt transect. You simply lay out your tape measure, then start at one end of the transect, placing the one metre squared quadrant beside the tape measure. You estimate and record the percentage of weed in each quadrant. When done counting, flip the quadrant forward up and along the transect. Continue counting and recording for the entire length of the 10 metre transect.

[Screen reads – Abundance. The number of a species found throughout an ecosystem]

This type of survey is useful when investigating abundance of a particular species. For the purpose of this Virtual Excursion, teachers have repeated the belt transect survey at three different sites. If you were to repeat this exercise for a different type of plant, or at a different location, you can include more sites for clearer data record and comparison.

A relative density survey is used to identify the distribution of plants. In riparian zones, it is difficult to access and accurately survey plants. The teachers are selecting a hundred metre section of the river. This is an estimation, and then they're estimating 10 metres inland. The hundred metres is parallel to the river. This makes it an estimated area of 100 metres by 10. In the estimated area, teachers are counting the number of weed-affected trees, and the number of non-weed-affected trees. To make it easier, one teacher counts the affected trees, and the other teacher counts the non-weed-affected trees. They tally their counts.

[Screen reads – The more you repeat a relative density survey in your study the more accurate your data will be]

This method can be repeated multiple times. The more you repeat the exercise, the more reliable the data is. Experiments and data collection should have at least three records of data, therefore three different sites. Here, [sample table of results shown] you can see the result for the quadrant survey, and the relative density survey. The sample fieldwork method shown in this episode can be used for other types of vegetation in your area.

List of sources and acknowledgements:

  1. Video – Drone footage of The Everlasting Swamp. We would like to thank The Everlasting Swamp National Park and Jessica Robertson Photography and Design for contributing their beautiful drone footage
  2. Narration – Voice over by Melissa Ellis, Southern Cross School of Distance Education
  3. Acknowledgment – We wish to thank Father Pop Harry Walker, Annabelle Walker, Roy Bell, Jubullum Local Aboriginal Land Council, Steve Walker, Marty Walker, David Foley, Upper Clarence River Landcare, Terry Moody, Steven Ross, Frederick Ellis

End of transcript

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