STATE WE’RE IN: The back story on the understory

by Michele Byers
”Not being able to see the forest for the trees” means we’re focusing so much on small things we don’t see the bigger picture.
   But sometimes the opposite is true — we see the forest, but don’t comprehend the smaller components that make up a forest ecosystem.
   Bicyclist and author Michael Heffler, president of the Princeton Freewheelers cycling club, sees forests frequently during his rides through the wooded countryside of Central Jersey’s Sourland Mountains and Wickecheoke Creek greenway.
   While riding, he got thinking about the forests and the trees: The leafy canopy and often-overlooked “understory” — the saplings, shrubs and plants that grow in the shadows of the big trees.
   Michael explained the understory in an essay for his cycling club newsletter, and I’m pleased to share part of it here:
   ”A healthy forest has an understory that is dense with young trees, shrubs and native plants. When you cycle around the Sourlands and the surrounding area, you will find an occasional healthy understory in a forest.
   ”You will also find many forested areas that have few, if any, saplings, and the dominant shrubs are invasive species like multiflora rose and Japanese stilt grass.
   ”Forests with healthy understories are those where deer hunters successfully control the deer population.
   ”We can’t blame the deer for this situation. Humans have killed off all of the deer’s local predators.
   ”About a hundred years ago, we also almost killed off the deer. Now there are laws that protect the deer from being over-hunted. But there are no laws that protect the forest from being overgrazed.
   ”When a forest is overgrazed by deer, a number of things happen — none of them are good. When storms come through, trees get knocked down, and new ones don’t take their place.
   ”This lets more light into the forest floor, which is normally a good thing, except invasive species benefit more than natives. The invasive species benefit because deer don’t eat them.
   ”Deer like native plants — particularly young ones. Birds that migrate from South and Central America looking for food have less to eat because many of the native insects don’t eat the invasive species.
   ”With diminishing food supply, songbirds start to disappear.
   ”Native plants also provide food and shelter for native reptiles and amphibians. All the little turtles, salamanders, toads and friendly creatures that you rarely see anywhere else all breed in the forest.
   ”Without the trees and native shrubs, they also start to disappear.
   ”One small creature that is prospering, unfortunately, is the deer tick. The other creature you don’t often see in the woods in the summer is people. The ticks are winning that battle thanks to their carriers, the deer.
   ”Now when you look into the forest and notice whether it has a healthy understory — one dense enough with saplings and native shrubs that it would be difficult to walk through — you’ll also see what else is and isn’t there.
   ”A sparse understory isn’t just bare of young trees, it is no longer a good habitat for songbirds, diverse native wildlife and native plants and shrubs. It also poses ticklish dangers for people.
   ”What can we do? Two things can help. First, we can plant more young native trees. Trees need to be planted in areas that are enclosed with deer fencing or protected so deer can’t eat them while they’re young.
   ”Planting more trees has a lot of benefits since trees are the lungs of the world and soak up carbon dioxide from the air, providing some deterrent to climate change. More trees create a more vibrant understory and a richer environment for the native shrubs and plants with the resulting better environment for birds, small creatures and people.
   ”Second, we can enable hunters to keep the deer population at a level that will sustain the forests. There is a strong case to be made that deer meat is local, organic, free range and tasty. If we can find ways to use deer meat as part of the local diet, benefits include less Lyme disease and fewer car and cycling accidents.
   ”That’s the understory.”
   Thanks to Michael for sharing his essay. The more we understand our forests, the more likely we are to protect them!
    Michele Byers is executive director of the New Jersey Conservation Foundation. For more information, contact her at [email protected] or visit NJCF’s website at