Citizen science, where the public pitches in to make large-scale analyses of data possible, has successfully predicted the path of a deadly plant disease, Sudden Oak Death, over a six-year period. 

The disease has killed millions of oak and tanoak trees in California and Oregon and can infect more than 100 susceptible host plants and can spread from nursery stock to residential landscapes. Starting in 2008, 1,000 volunteers collected leaf samples from trees in metropolitan and urban-wildland areas. 

Accurate predictions about sudden oak death's spread allowed scientists to target treatments to the most vulnerable areas. Follow-up evaluation showed that citizen scientists were as effective as experts in identifying and collecting diseased tree leaves, regardless of their background in science. 

The annual Sudden Oak Death Blitz, which includes extensive publicity during peak periods for the disease, involves high school students, homeowners, tree specialists, firefighters, teachers and many others.

"Sudden oak death is the Ebola of the plant world, the most serious disease threat to nonagricultural plants," says Ross Meentemeyer, director of the Center for Geospatial Analytics at North Carolina State University and lead author of the paper in Frontiers in Ecology and the Environment. 
"We were able to get data from backyards in the Bay Area, along with other under-sampled locations. That data was used to develop accurate computer models for the disease's spread, showing that properly trained and educated citizen scientists can collect data that's just as reliable as that of professionals."

The crowdsource approach could be adopted for other large-scale research projects, from tracking wildlife populations to fighting human disease outbreaks, the authors say.

Citation: Ross K. Meentemeyer, Monica A. Dorning, John B. Vogler, Douglas Schmidt, and Matteo Garbelotto "Citizen Science Helps Predict Risk of Emerging Infectious Disease" May 1, 2015, Frontiers in Ecology and the Environment