Dying trees in cities? Blame it on the pavement
- Date:
- March 4, 2019
- Source:
- North Carolina State University
- Summary:
- A new study of urban tree life in the Southeast shows pavement and concrete may have a bigger effect than longitudinal warming.
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A North Carolina State University study examining urbanization, scale-insect abundance and latitudinal warming on tree health in the Southeast captured a few surprising results.
The study showed more scale insects on red maple trees in the midrange of eight cities within a 10-degree latitudinal difference, from Newark, Delaware, to Gainesville, Florida.
Cities in that midrange, including Raleigh and Asheville, showed poorer tree health, due mostly to these high volumes of tree-destroying gloomy scale insects (Melanaspis tenebricosa), which appear as tiny bumps on tree branches and leaves.
"Impervious surfaces -- basically concrete and pavement -- near trees was a better predictor of scale-insect abundance than temperature, and thus a better predictor of poor tree health in the study area," said Michael Just, an NC State postdoctoral entomology researcher and corresponding author of a paper describing the research.
The finding was surprising, Just said, as the study's original hypothesis predicted higher scale-insect abundance at lower latitudes -- the study's southernmost areas.
"What we've learned over the years in natural areas like forests didn't translate in this study, which means we may need to consider if other natural-system theories can be used in urban areas," Just said. "That's important if we want to have reliable predictive ecological models."
Story Source:
Materials provided by North Carolina State University. Note: Content may be edited for style and length.
Journal Reference:
- Michael G. Just, Adam G. Dale, Lawrence C. Long, Steven D. Frank. Urbanization drives unique latitudinal patterns of insect herbivory and tree condition. Oikos, 2019; DOI: 10.1111/oik.05874
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