Projected Distribution of Common Ragweed Modeled in U.S.

THURSDAY, Dec. 6, 2018 (HealthDay News) — Common ragweed is expected to expand at the northern margins of its current distribution, according to a study recently published in PLOS ONE.

Michael J. Case, Ph.D., from Case Research LLC in Seattle, and Kristina A. Stinson, Ph.D., from the University of Massachusetts in Amherst, built a maximum entropy predictive model using climate and bioclimatic data and more than 700 observations across the eastern United States to better understand how climate change may affect the distribution of common ragweed.

The researchers found that the model performed well; using four uncorrelated variables (precipitation seasonality, mean diurnal temperature range, August precipitation, and January maximum temperature), the area under the receiver operating characteristic curve score was 0.765. Using a suite of 13 global climate models under two future greenhouse gas scenarios for midcentury and late century, potential future common ragweed distribution was projected. A substantial contraction of common ragweed was seen in central Florida, the southern Appalachian Mountains, and northeastern Virginia, while areas of potential expansion were seen at the northern margins of the current distribution, notably in the northeastern United States. Most of this increase is projected to occur by midcentury.

“We don’t have a lot of models like this that tell us where individual species may go under different scenarios,” Stinson said in a statement. “But ragweed happens to be quite abundant, which made this study feasible.”

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