Look closely at any urban or forest tree and you will find hundreds of insect and mite species scattered here and there feeding on leaves or sap. Most never become pests. A few species become pests only after some change in the environment – like warming temperatures. These are called sleeper species.
Your backyard is the setting for a great ecological debate, and you may engage in this debate, knowingly or not, every spring.
Outside of cities, in natural environments, it has long been noted that herbivore abundance and feeding increases near the equator where the climate is warmer. But does this latitudinal-herbivory pattern observed in natural areas apply to cities?
Does it have to be one or the other? Conservation or pest management? People or birds? I don’t think so, and a new paper from our lab in PeerJ supports this perspective.
Like we observed in Raleigh, we found that impervious surface was a robust predictor of tree condition, and that one set of thresholds could be used for red maples across the Southeast.
We are not the only scientists using cities as surrogates for climate change. However, this line of research is in its infancy. We conducted a literature review, led by postdoc Nora Lahr, to compile all the research we could find in which cities were used to predict the effects of climate change.
It is nice to be reminded of why I am an ecologist, why I study trees, and why I care about helping trees grow in cities. Photosynthesis is cool!
As a Masters’ student in the Frank lab, I study relatively small organisms called ground beetles. Ground beetles are used to monitor forest health because they are common, vary in food and habitat requirements, and are sensitive to human-caused disturbances.
Cities are hot and often dry. This makes the plants dry and unhealthy. But what about the animals? They can gain water by ‘drinking’ from moist soil or dew, or by eating plants that are mostly water. But what if they can’t find enough to drink?
A mystery began to nag at me. Some trees in the hottest areas within cities were covered in insect pests and still looked vigorous, while other trees with the same pest densities withered.