A new study shows how reports from the public can help scientists to track diseased trees.

  • 19
  • JUL
  • 2017

A new study concludes that members of the public can accurately report disease outbreaks affecting our native trees and that by combining their findings with official survey effort better quality predictions of disease distributions can be made.

Published online today [19 July] in Proceedings of the Royal Society B, the work comes from a joint team of scientists from Rothamsted Research, the University of Salford and Forest Research. The study was part of a programme to understand the causes and distribution of acute oak decline (AOD) in England and Wales. It developed and refined a mathematical model that enabled a formal survey to make the most of a catalogue of reports from the public about AOD affected trees.

Amateur naturalists can provide valuable scientific data by reporting observations in their gardens and beyond. Such assistance from “citizen scientists” could have a huge impact on the scope of future surveys, according to Nathan Brown, a computational biologist at Rothamsted, which led the study. “Sightings from the public provide a valuable resource.  The challenge for researchers is to make the most of their efforts by developing new ways to use it.” he says.

The results showed clear similarities between the locations of reports gathered from the scientific survey and those from the public. However, the greatest benefits were seen when the datasets were combined - Using all available information increased the accuracy of predicted distributions. 

The work has proved so successful that the team is keen to work further with citizen scientists and is directing anyone interested in contributing data to use the tree alert website provided by Forest Research’s Tree Health Diagnostic and Advisory Service (THDAS), or to register online at Observatree, a collaborative network of volunteer tree health surveyors who are trained by Forest Research and managed by the Woodland Trust.

“Citizen science is an exciting way to boost numbers on the ground, but we also need a way to make sense of the numbers that come back,” says Stephen Parnell, an epidemiologist at Salford. “This paper showed that citizen science information can be successfully integrated into mathematical approaches to predict where disease is”.

The challenge when using reports from the public, even reports subsequently verified by experts, is the inherent bias of the sampling; Public reports are ad-hoc, sent in at times and places that are convenient. Statistical analysis assumes that sampling is random, so new methods are required.

"We were really pleased with the accuracy of that final map” notes Brown. "Volunteers can contribute to an efficient early warning system for pests and diseases, and our findings suggest that their discoveries can also be used to define the distribution of affected woodland.”

The results are welcomed by Sandra Denman, AOD project director and principal pathologist at Forest Research. “Having a reliable account of the distribution of AOD is crucial. Researchers are then armed with critical information about spread, and can estimate the locations of vulnerable trees, which leads to a greater understanding of how the disease operates.”

The project received funding from Department for Environment, Food & Rural Affairs and the Forestry Commission. Research into the distribution of AOD continues with support from Woodland Heritage. 

About University of Salford

The University of Salford draws on an iconic industrial heritage to offer real world learning and research experiences and is a leader in media and digital, business, technology, science, engineering and health. Its Industry Collaboration Zones strategy to provide degree courses embedded in industry is proving successful with applications rising by 25% in two years and recruitment bucking the national trend. Salford features in the QS World University Rankings for built environment and civil engineering, and won the Times Higher Business School of the Year Award in 2014 and the Times Higher Research Project of the Year 2016 for an environmental impact study of Chernobyl.

About Forest Research

Forest Research is an agency of the Forestry Commission. It carries out world-class scientific research and technical development relevant to forestry to inform policies for sustainable forest management. 

About Rothamsted Research
Rothamsted Research is the longest-running agricultural research institute in the world. We work from gene to field with a proud history of ground-breaking discoveries, from crop treatment to crop protection, from statistical interpretation to soils management. Our founders, in 1843, were the pioneers of modern agriculture, and we are known for our imaginative science and our collaborative influence on fresh thinking and farming practices.
Through independent science and innovation, we make significant contributions to improving agri-food systems in the UK and internationally. In terms of the institute’s economic contribution, the cumulative impact of our work in the UK was calculated to exceed £3000 million a year in 20151. Our strength lies in our systems approach, which combines science and strategic research, interdisciplinary teams and partnerships.
Rothamsted is also home to three unique resources. These National Capabilities are open to researchers from all over the world: The Long-Term Experiments, Rothamsted Insect Survey and the North Wyke Farm Platform.
We are strategically funded by the Biotechnology and Biological Sciences Research Council (BBSRC), with additional support from other national and international funding streams, and from industry. We are also supported by the Lawes Agricultural Trust (LAT).
For more information, visit; Twitter @Rothamsted
1Rothamsted Research and the Value of Excellence: A synthesis of the available evidence, by Séan Rickard (Oct 2015)

The Biotechnology and Biological Sciences Research Council is part of UK Research and Innovation, a non-departmental public body funded by a grant-in-aid from the UK government.
BBSRC invests in world-class bioscience research and training on behalf of the UK public. Our aim is to further scientific knowledge, to promote economic growth, wealth and job creation and to improve quality of life in the UK and beyond.
Funded by government, BBSRC invested £469 million in world-class bioscience in 2016-17. We support research and training in universities and strategically funded institutes. BBSRC research and the people we fund are helping society to meet major challenges, including food security, green energy and healthier, longer lives. Our investments underpin important UK economic sectors, such as farming, food, industrial biotechnology and pharmaceuticals.
More information about BBSRC, our science and our impact.
More information about BBSRC strategically funded institutes

About LAT
The Lawes Agricultural Trust, established in 1889 by Sir John Bennet Lawes, supports Rothamsted Research’s national and international agricultural science through the provision of land, facilities and funding. LAT, a charitable trust, owns the estates at Harpenden and Broom's Barn, including many of the buildings used by Rothamsted Research. LAT provides an annual research grant to the Director, accommodation for nearly 200 people, and support for fellowships for young scientists from developing countries. LAT also makes capital grants to help modernise facilities at Rothamsted, or invests in new buildings.