Citizen scientists track ‘Ebola of the plant world’

From 2008 to 2013, volunteers collected more than 6,000 samples of tree leaves in central California. The plants had potentially been stricken with sudden oak death, a disease that has decimated millions of trees on the West Coast.

That citizen science program, called the Sudden Oak Death (SOD) Blitz, has aided efforts to better understand and predict the spread of the disease, researchers report in Frontiers in Ecology and the Environment. The newly-gained knowledge could help managers target areas that might fall next to sudden oak death, dubbed “the Ebola of the plant world” by one study author in a press release.

SOD Blitz recruited more than 1,600 volunteers during the six-year study period by issuing press releases, making radio announcements, and connecting with nature-based community groups, among other strategies. The people who signed up included high school students, teachers, firefighters, and docents. Each participant learned how to identify signs of sudden oak death and collect leaves, pinpointing the trees’ locations with a mobile app.

The volunteers collected 1,929 infected samples and 4,575 uninfected samples, the study authors report. When the team attempted to predict the risk of infection using data collected before SOD Blitz began, their results were 65 percent accurate. But when they added citizen science data from 2008-12, their predictions were 78 percent accurate.

The Blitz data highlighted more sites that might be vulnerable to infection. About 3,900 square kilometers in the study area are considered high-risk, including northern Sonoma County and southern Big Sur. The updated models also suggest that dense urban areas are less likely to be hit by the disease.

Finally, the team evaluated the accuracy of disease detection among volunteers with a professional science background — such as training in forestry or plant pathology — and those who didn’t know much about sudden oak death before entering the program. During the last couple years of the study, the amateurs’ success rate was on par with that of the professionals. And the newbies gained valuable knowledge about environmental issues, making the program a win for outreach as well. Roberta Kwok | 7 May 2015

Source: Meentemeyer, R.K. et al. 2015. Citizen science helps predict risk of emerging infectious disease. Frontiers in Ecology and the Environment doi: 10.1890/140299.

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