About 90 percent of a forest's plant diversity lies in its understory, a layer of vegetation beneath the main canopy. Too many deer grazing in an area can decimate that plant layer.
The new augmented reality app AR Perpetual Garden aims to show people exactly what a healthy forest environment looks like compared to an unhealthy one.
The app uses the camera on a device to populate a user's surroundings with plants native to western Pennsylvania. In the "Woodland in Balance" setting, users see bushy, low-growing white trillium and the reaching vines of greenbrier plants; the sounds of birds and insects native to the region play in the background.
The "Woodland out of Balance" setting shows what plants remain when there are too many deer: ferns and plants with few leaves or blooms. The bird and insect sounds are also diminished.
"It's a very different looking forest," said app co-creator John Wenzel, director of the Powdermill Nature Reserve. "Not very diverse and also not very attractive."
When the understory is lost to deer, insects that feed on those plants are affected, and then the birds that feed on those insects are at risk.
"One of the things we wanted to do was to show people that preserving the forest is more than just growing trees," Wenzel said. "That some of these things, like controlling the white tailed deer, are actually very important to fundamental biodiversity."
Co-creator Maria Harrington, a professor at the University of Central Florida, said she sees this app as an educational tool.
"What's unique is that this is essentially giving a child or novice an expert scientist's imagination," Harrington said. "Many of these flowers bloom very shortly, and people don't see the beauty that's out there."
To find specific information about the types of plants featured in the app, you need to touch a panel called "Plant Info," which sends the user to an external website for the Powdermill Nature Reserve. The creators say making the plants clickable within the app is a next step.
To curb overpopulation, Allegheny County recommends that residents grow deer resistant plants in gardens and not purposely feed deer.