Computer models developed by the University of Chicago and Argonne National Laboratory predict that warmer, drier conditions in North America will limit the expansion of a fungus that normally suppresses the spread of sponge worms, an invasive species. It has caused tens of millions of dollars in damage. Forests
The research, published in , emphasizes the importance of accounting for multiple organisms and their interactions when predicting the potential impacts of climate change, as warmer temperatures cause unpredictable domino effects in ecosystems.
“The majority of previous climate change studies have looked at individual organisms, but a small amount of climate change can have a large effect when you apply it to multiple species,” said Greg Dwyer, Ph.D., professor of ecology and evolution at UChicago. I mix.” author of the new study. “Therefore, computer models are critical to understanding the consequences of climate change on species interactions.”
Small changes result in big impacts.
The spongy moth () was first introduced into the hardwood forests of New England in 1869. Native to Europe, female moths lay eggs on surfaces corresponding to branches, wood piles and outdoor furniture. Eggs include objects when people move them, so the bug has spread removed from where it was first by accident released in Massachusetts. Sponge moth caterpillars feed on the leaves of trees and shrubs, especially oak trees. For a long time after their introduction, the caterpillars wreaked havoc through forests, uprooting and killing acres upon acres of trees.
In 1989, a deadly infection attributable to a fungus began spreading in sponge worms. This fungus can be not native to North America, but nobody knows obviously how or when it arrived. It can have been introduced intentionally to regulate pests, or it can have been by accident delivered to America from Japan, where it originated. Nevertheless, it has managed to maintain the spongy worm under control ever since, saving tens of millions of trees.
Another pathogen, nucleopolyhedrovirus (NPV), also can control insects, but requires large populations to spread. The natural advantage of the fungus is that it may possibly grow and infect small numbers of insects before causing an excessive amount of damage, but provided that conditions are cool and moist.
“Even a small decrease in mortality for moths leads to a large increase in degradation,” Dwyer said. “If they don't get killed one year at low density, the next year they'll go back to high density. You have this multiplication process going on.”
Not pessimistic enough.
Dwyer spent his profession modeling infectious diseases and interactions between species starting from wild rabbits to insects. In 2004, in one among his first publications at UChicago, he developed a model that accounted for NPV infection rates between the sponge worm, its predators corresponding to mice and squirrels, and the virus. In 2020, his lab designed more models to find out how insect population density and weather conditions affect the spread of the fungus. These models showed that incorporating climate data produced a lot better predictions than models that didn't account for climate, planting the seeds for the brand new study.
Dwyer and his student Jiawei Liu worked with Jiali Wang, PhD, an atmospheric scientist within the Environmental Science Division at Argonne National Laboratory, and Rao Kotamarthi, chief scientist within the Environmental Science Division at Argonne, to include the brand new climate data more accurately. could be done Model for infection of sponge worms. Wang and Kotamarthy concentrate on taking large-scale climate change models, say for all of North America, and scaling them all the way down to areas as small as a piece of a state. This allowed Dwyer's team to account for more significant differences in weather patterns and bug populations across multiple regions.
The resulting predictions were disappointing. As climate change brings warmer and drier conditions to forests, fungal infection rates will drop sharply over the subsequent few a long time — meaning more bugs will survive to destroy more trees. While that could seem far in the long run, below-average rainfall and above-average temperatures lately have already led to large sponge bug outbreaks, which Dwyer said he doesn't expect to occur anytime soon. was
“Our estimates were pessimistic, but perhaps not pessimistic enough. This is very worrying,” he said.