What is Citizen Science?

Citizen science refers to any scientific project where volunteers perform research-related tasks such as observation or measurement to help assess the health of the nations treescape.

Some of the ways that Citizen Science projects can help safeguard plant health are:

  • detection, surveillance and early warning of a pest or disease
  • supporting official surveillance and outbreak management
  • supporting research into particular pests and diseases
  • mapping particular pests and diseases
  • capturing the values of our plants including the ecosystem services of healthy plants, assessing the value loss due to a particular pest and disease, and providing evidence to build the case for intervention

Observatree: An early warning system for tree health

The UK government and the devolved governments have worked with partners from the public and charitable sectors to deliver Observatree; a tree health early warning system based on citizen science that supports official surveillance on tree health. This partnership project involves Forest Research, Fera Science Ltd, the Woodland Trust, the National Trust, and government. The project has developed a UK wide network of trained volunteers to survey trees and report the presence of 22 high priority pests.

Observatree volunteers have completed nearly 14,000 surveys in 6 years, including 2,489 reports of priority pests and diseases, providing valuable information to support both policy and operational decisions. Central to Observatree’s success has been the development of TreeAlert, a tree health reporting tool run by Forest Research that feeds into the government surveillance system.  Last year during National Plant Health week we asked the general public to become citizen scientists, and get involved to check their sweet chestnuts for tree diseases.



TreeAlert is the online reporting tool for tree pests and diseases, managed by Forest Research with funding from Defra, Forestry Commission, Scottish Forestry and Welsh Government. It is a valuable aid, allowing you to quickly report any suspect findings of tree pests and diseases which are of concern in Britain. Anyone can report through TreeAlert.

Help us gather information about the health of the nation’s trees, woodlands and forests by reporting signs of dangerous tree pests and diseases using TreeAlert.

To submit a useful report of a tree health problem you will be taken through a series of pages where you will be asked a number of questions about your observation. The more information you can provide, the more useful your report will be.

The ‘Check a Sweet Chestnut’ Citizen Science Call 2023 

In 2023, between National Plant Health Week in May and National Tree Week in November, the RHS, Defra, APHA, Forest Research and Observatree invited the public to become a good plant health citizen and submit data on sweet chestnut health through TreeAlert.

We wanted to know where there are healthy and unhealthy sweet chestnuts across the UK so we can understand how far sweet chestnut blight and oriental chestnut gall wasp have spread since they were first reported. The information provided will help us to produce an up-to-date map of healthy and unhealthy sweet chestnut trees and tell us whether our actions to control the spread of blight and gall wasp are working.

Sweet chestnut trees have prickly seed cases
inside the prickly cases are edible nuts
oriental chestnut gall wasp on a sweet chestnut leaf, causing swelling at the central vein
sunken and discoloured bark caused by sweet chestnut blight