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Citizen Science Projects

THECA Citizen Science Projects

Citizen Science (CS) is about community citizens contributing to advancing science knowledge through being involved in scientific projects. Scientists are heavily involved in the design of projects with Volunteers collecting environmental data and sometimes collaborating in the design of those projects. The Office of the Queensland Chief Scientist has produced a video which highlights the many CS projects operating in Queensland, see

THECA’s current CS Projects are the evaluation of large-scale tree plantations at Wacol, and the carbon dioxide monitoring project. Details of these projects are below.

Evaluation of 2MT Plantings at Wacol - June 2020 update

A Citizen Science Grant of $16,000 was awarded to The Hut Environmental and Community Association (THECA) Inc. to monitor the condition and health of trees planted under the Brisbane City Council’s 2 Million Trees Project. The trees and shrubs at Wacol were planted in 2011/12.

Twenty volunteers were recruited, of which 18 have remained until December 2019.

Thirteen, 50 X 50 Metre Plots were marked out across the Wacol site. On each of the Plots, corrugated iron sheets, hardwood sleepers, roof tiles and tree wraps were placed for reptile refuges. Sixty hair traps and six motion cameras were located for a two-week period on three Plots. These traps and cameras will be placed in the plots again for another two week period later in 2020.

A Training Workshop was held on 26th October at Pooh Corner Environmental Centre. Volunteers were addressed on topics such as Plant Identification and Monitoring Methods; Bird Identification and Survey Methods; Reptile Identification and Survey Methods); and Mammal Survey Methods followed by a field session to assist volunteers to become familiar with the trees planted at the Wacol site with Workshop Speakers demonstrating identification and survey methods.

Three Citizen Scientist groups were formed. Groups were allocated three 50 X 50 Metre Plots each, scattered throughout the Wacol site. One Plot was used as the training plot. The three remaining Plots will be surveyed by the Project Coordinators.

Each group has started recording vegetation occurrence on their allocated plots. One survey is required for the entire project. Each group has started their monthly surveys of birds and reptiles which was interrupted by the COVID 19 virus. Surveys were suspended at the end of March and will commence again in July 2020, if state laws and restrictions allow.

To date, trees and shrubs have done quite well, although some deaths have occurred. The area has experienced drought for a long time since 20111/12 as evidenced by soil cracks and trees and shrubs looking very ‘sick’, possible dying. A short, heavy rainfall event in February produced a new flush of growth.

Several native fauna species have been observed within the Wacol site and on the Plots such as Beaded Dragon, Eastern Brown snake, Collared Sparrowhawk, brush turkey and three species of macropod. Hairs collected in the hair tarps will be sent for identification and animals will be identified by Justin from the motion camera cards.

Groups will continue to conduct bird and reptile monthly surveys over winter and Spring and complete the vegetation monitoring.

Full flora and fauna results will be tabled after September, 2020.

G Siepen & D. Cole (Project Coordinators)

THECA Carbon Dioxide Monitoring Project

In 2019, THECA approved a pilot project led by THECA member Charles Worringham to undertake some monitoring of carbon dioxide concentrations in our local area. Unlike the measurements of well-mixed clean air at NOAA’s Mauna Loa station in Hawaii, or Australia’s Cape Grim station on the north-west tip of Tasmania, ground-level measurements of localised atmospheric concentrations can give an indication of emissions from an urban area and potentially point to specific sources (such as traffic and land disturbance) and sinks (including bushland and other vegetation).


Climate change, driven by the emission of carbon dioxide and other greenhouse gases, is having increasingly clear effects on our environment globally, nationally and right here in Brisbane.

The changes are not only seen in higher temperatures and exacerbation of drought and bush-fire conditions, but in ecosystem changes such as disruptions to migration patterns, food and host-plant availability and other phenological cycles.

As an organisation focussed on the environment and community education, THECA can contribute to the understanding of carbon dioxide patterns in an urban area and its surrounds. We understand that this is one of the first citizen science projects to undertake this kind of monitoring.

When the Hut was built in World War II, atmospheric carbon dioxide stood at about 310 parts per million (ppm), and when THECA was founded in 1994, that value had risen to 360ppm. Today, atmospheric CO2 stands at about 415 ppm, higher than at any time in the last 800,000 years, and thought to be rising faster than at any time in the last 65 million years. More than 85% of cumulative anthropogenic CO2 emissions have been released in the Hut’s short lifetime, and more than half since THECA was founded1.

In Brisbane, fuel combustion in vehicles is likely to be the major anthropogenic source of CO2. Brisbane’s cars produced the equivalent of about 4 million tons CO2 in 2016, estimated from State government data.2 To put this in perspective, there are 34 countries whose overall emissions are less than those from Brisbane’s cars (not counting trucks, buses etc.). Researchers at King’s College London have routinely measured elevated CO2 levels adjacent to major roads.

Equipment and measurements

The project uses a relatively low-cost non-dispersive infra-red CO2 sensor (Senseair K33), controlled by a Raspberry Pi computer. Each sensor and controller can be mounted in a protective housing, and data streamed via a USB 4G modem. We have written our own software to control the sensors, and thank Alan Barlow for assistance sorting out some communication protocols for the sensor t an early stage in the development of the project.

These sensors have been shown to have acceptable resolution to detect changes of a few parts per million, and if properly calibrated have been shown to track CO2 concentrations quite faithfully compared to very expensive and specialised devices, such as ring down cavity spectrometers used by professional research groups3.

We are very fortunate to have the assistance of Dr. Alistair Grinham, Senior Research Fellow in the School of Civil Engineering at the University of Queensland. Alistair is providing both advice and help with calibration, using sensitive gas chromatography equipment to measure air samples taken in conjunction with some of the sensor measurements.

Co2Measurements         Co2Measurements2

Figure 1 shows one of the sensor kits disassembled and Figure 2 shows the installed equipment. The first three devices are operating in the north-west of the City Centre, Chapel Hill as a suburban site, and Jimboomba to sample the prevailing southerly air before it reaches the urban area).

Figure 3 shows a 24 hour record of some early data. The CO2 level is generally higher at night because of the absence of daytime photosynthesis as well changes in the atmospheric boundary layer over the region at night-time. Ona any given day, winds can create mass movements of air from rural areas with relatively low concentrations, or across the city, carrying higher levels.

The advantage of building a network of sensors as opposed to a single site (which usually involves very expensive research-grade equipment and professional staff) is that interesting spatial patterns of change may emerge. Wind directions, traffic patterns and other variables can help give a context to the observed concentrations.

We accelerated the data collection phase of the project to capitalise on the low traffic conditions of the Coronavirus lockdown. Once enough data is in, we may be able to assess how much Brisbane’s lockdown reduced CO2 levels. Although we have only a very small quantity of pre-lockdown data, we may have sufficient during the lockdown to make comparisons with the next few months as economic activity returns. As of late May, reports of decreased urban CO2 have been reported for eight European cities, some showing very substantial drops.

More information

If you would like more information about this project, or if you or your community group might be interested in hosting a monitor, please contact us via THECA’s contact page.

1 Data from OWID based on the Global Carbon Project; Carbon Dioxide Information Analysis Centre (CDIAC); Gapminder and UN population estimates (


3 Martin, C. et al. (2017). Evaluation and environmental correction of ambient CO2 measurements from a low-cost NDIR sensor. Atmospheric Measurement Techniques, 10, 2383–2395.