Citizen scientists have a role to play in our woods and cities

Citizen science: how do your trees measure up? Yui Mok/PA

Everyone can contribute to scientific research, whether by exploring far-flung galaxies from the comfort of their computer, or by checking how clean the air is in their street by examining lichens growing on trees. Although “ordinary people” have been participating in scientific research for hundreds of years, the number of such citizen science projects in the last decade has dramatically increased.

Now millions of people around the world are engaged in citizen science. It is a huge development in the way scientific research is conducted, and how scientists and the public interact. Environmental questions such as how species interact with their environment, how plants and animals are responding to changing climates, and the spread of pests and diseases, are especially suited to a citizen science approach as it allows large amounts of data to be collected over wide geographical areas.

A particularly topical citizen science project is the OPAL Tree Health Survey. OPAL is a nationwide programme, supported by the Big Lottery Fund, which aims to engage people with their local environment through participation in surveys. One focuses on the pests and diseases that affect trees - you can’t have missed reading about ash dieback, the disease caused by the fungus Chalara fraxinea, which infects the tree and causes leaves to turn black and branches to die.

Fungal spores are carried on the wind, and the sale and transport of infected trees also spreads the disease. Ash trees on continental Europe have been badly affected, with reports of Denmark losing between 60-90% of its ash trees.

The ash is an important part of the British landscape, and is widely used in making furniture and wooden tools due to it’s attractive grain and flexibility. Ash canopy is less dense than many other native trees, allowing a wide range of invertebrates and mammals to thrive beneath. It’s often planted as part of hedgerows, and around 5% of British woodlands are ash-dominated, so loss of the species would have a significant impact on the landscape.

Since the appearance of the fungus in Britain in 2012, Forestry Commission and Fera staff have checked trees for signs of the disease, and have found 563 confirmed incidences of the disease. This is likely to be only scratching the surface, but the departments simply don’t have enough staff to survey further. That’s where the OPAL Tree Health survey comes in.

Researchers at the University of York, Plymouth University, Imperial College London, Fera and Forest Research have drawn up guides to show people how to go out and check the health of trees. The survey focuses on ash, oak, and horse chestnut trees, lists the common pests and diseases that affect them, and more serious threats such as Chalara and the oak processionary moth.

Surveying woodland for these pests and diseases is important because records of where they are (and where they aren’t) are important for helping to manage their spread. So far over 1,000 people from all across the UK have returned results from the OPAL Tree Health survey.

Citizen science projects such as this are sometimes criticised because of concerns about the quality of data. Some scientists are sceptical that members of the public can collect data reliably. OPAL tries to improve data quality in several ways. The identification guides are designed to be as simple as possible, and are tested with members of the public to ensure that they are. OPAL trains group leaders such as teachers, environmental educators, foresters and members of voluntary organisations to demonstrate how to conduct the survey. They also teach key identification features of the pests and diseases. Those that have been trained have since gone on to train others, but there are also online materials for those who have not attended a training course. Lastly, OPAL encourages people to submit photographs of any pests and diseases that they find, which allows scientists to verify sightings.

Citizen science projects can benefit scientists and participants in many ways, and at the same time generate valuable scientific data. Participants can gain a better understanding of science, and by engaging with the public scientists can improve their skills at communicating their findings.

If you’d like to take part in the survey then just download the materials and get started - before the trees near you start losing their leaves.