Sarah Duddigan talks citizen science and the Tea Bag Index on TV

Sarah Duddigan poses with tea bags-smThis week University of Reading and Royal Horticultural Society (RHS) PhD student Sarah Duddigan has been filmed for an Austrian children’s science TV programme, talking about her contribution to a decomposition rate citizen science project, known as the Tea Bag Index – UK.

The Tea Bag Index is a novel method to measure decomposition rate in soil. Decomposition (the breakdown of organic material into its smaller constituents) is an important process for the release of nutrients into soil for plants to use. Therefore gaining a better understanding of decomposition in soil will be of great value to gardeners in the UK. The method is simple, UK participants are recruited through the RHS and posted some tea bags to bury in their garden. After three months they dig them up and send them back, along with a soil sample.

Decomposition of organic matter (i.e. dead plant and animal remains) in soils is an important process in any ecosystem.

Decomposer microorganisms feed on the organic matter and break it down into its simplest components. As organic matter is decomposed, water, carbon dioxide and nutrients are released. Meaning that, any excess nutrients are released and are available for plants to use to grow.

Maintaining a healthy and vibrant garden is the aspiration of most gardeners and healthy fertile soil is a key component of this. Therefore, a better understanding of decomposition rates in garden soils will be of great value to gardeners across the UK.

While having an active microbial population decomposing organic matter is important for soil health, they are not without their problems. While organic matter is decomposing, it releases the greenhouse gas carbon dioxide (CO2) into the atmosphere. A fast decay leads to more CO2 in the atmosphere and slow decay could lead to a greater proportion of carbon remaining in the soil. It is estimated that soils store a gigantic 2,300 billion tons of carbon worldwide; triple the amount than all the worlds plants. Therefore in order to gain a better understanding of global CO2 emissions from soils it is vital to know more about the rate of decomposition.

The data from the UK therefore can also be combined with data being collected across Europe (or across the world in fact) in order to gain a better understanding on the role of decomposition in global carbon emissions and the contribution to climate change.

This seems to be a contradiction, on the one hand decomposition is good for plant health, but on the other has the potential to contribute to climate change. This is why projects such as this, which aim to gain a better understanding of decomposition rates in soil, are so important.

For more information, and updates on the progress of the project, see the links below:





Lecturer Dr Hilary Geoghegan hosts citizen science conference

Image from: Cheli Cresswell ‏@chelicresswell   “Kicking off Day 2 of #BESCitSci. Today's focus: #citizenscience participants.  #citscipeople @DrHG @AlisonDyke_SEI”

Image from: Cheli Cresswell ‏@chelicresswell
“Kicking off Day 2 of #BESCitSci. Today’s focus: #citizenscience participants. #citscipeople @DrHG @AlisonDyke_SEI”

On 12th May, one of our lecturer’s Dr Hilary Geoghegan hosted a citizen science conference at the British Ecological Society in London. Working with colleagues from the Stockholm Environment Institute at the University of York, Hilary welcomed participants for a one-day event to discuss the ‘human’ element of citizen science – specifically the volunteers, professional scientists, practitioners and policymakers that make up this ever-growing field.

The event attracted over 40 researchers and practitioners interested in the social dimensions of citizen science. A widely accepted definition of citizen science is the participation of non-professionals in professional science projects. However, more work needs to be done to reflect on participation in citizen science – a research approach that is developing at a breakneck pace. Dr Geoghegan said: “My research area of enthusiasm, namely the emotional affiliation we have towards things and activities we care about, is of significant interest to professional scientists, research councils and policymakers as they establish the ways in which they will engage with citizen science in the future. Without an understanding of why people do and do not participate, citizen science projects may fail.” You can find tweets on the subject via the hashtags #BESCitSci and #CitSciPeople

Dr Geoghegan holds an ESRC Future Research Leader award and has used the time and resources offered by the grant to examine the social aspects of tree health citizen science. She has been interested in the place of ‘citizen science’ within emerging tree health policy and the enthusiasm of scientists, policymakers, press officers, web editors and database managers for citizen science. Her next step is to interview volunteers in tree health citizen science projects to understand why they survey and monitor trees.

In 2013 Dr Geoghegan joined the Department of Geography and Environmental Science and since then she has travelled to Australia to discuss enthusiasm for trees in Melbourne and Sydney. She has also spent time building networks with colleagues in Biological Sciences on tree health. She is a founder of the UK’s Tree Health Citizen Science Network.


If you’re interested in this area and would like further information please contact Hilary: or follow her on Twitter: @DrHG. She also hosts a blog focussing on life as an academic and her research interests.