New paper: Urban warming reduces aboveground carbon storage
Through years of studying urban trees and the insects that eat them, we, the Frank lab, have discovered that warming in cities leads to more pests. We also know how: where it’s warmer, insects survive and reproduce better, and the effects of their natural enemies are diminished. In most conversations we have about this work, explaining these discoveries leads to the question: but what does this mean for the trees?
Street trees perform essential services like removing pollutants from air. Photo: EK Meineke
I tackled this question with the help of Elsa Youngsteadt by studying how warming and pests affect tree drought stress and functions like photosynthesis and stomatal conductance. Of course, as in my previous work, I studied the charmless but interesting oak lecanium scale on willow oaks which are among the largest and most common street trees in Southeastern cities.
Oak lecanium scales on willow oak. Photo: EK Meineke
Over three years we took hundreds of tedious measurements (thanks Elsa!) to figure out how fast our trees were growing and thus how much carbon they were removing from the air and storing in their tissue. This is called carbon sequestration and is a critical way trees reduce carbon pollution and global warming.
Elsa measuring photosynthesis. Photo: EK Meineke
In a new paper, we show that the urban heat island effect significantly reduces street tree growth. This is because trees in warmer urban areas photosynthesize less. When these effects were scaled up to all the willow oak street trees in Raleigh, warming reduced citywide carbon sequestration by 12%. However, insect pests like scales and spider mites had minor effects on tree growth compared to warming, at least in the short term.
. . . for full post, see: EcoIPM
More natural history stories
“Rare sight, common occurrence: Parasitoid wasp emerges from a scale insect,” ECOIPM, 12 August 2015.
“This is what science looks like at NC State: Emily Meineke,” NC State News, 7 November 2014.
“June beetle boogie,” Your Wild Life, 27 October 2014.
“When fieldwork fails . . .” ECOIPM, 8 July 2014.
“Buttercup oil beetle goes on odyssey, lands in my apartment,” Your Wild Life, 28 May 2014.
“Why your local fungus farmer might not be your friend,” Your Wild Life, 19 January 2014.
“Hot in the city: Urban heat and the future of trees,” ECOIPM, 27 March 2013.
“So easy everyone can do it: How we’re like cave men and ants,” Your Wild Life, 25 January 2013.