Syracuse.com - Botanist: White-tail deer raising havoc by browsing too much in forests

[HuntingNY-News]

Thomas Rawinski, of the U. Forest Service, said botanists are usually the first people to see the impacts. The average person looks at a forest and the trees and just doesn’t see what’s going on.

David Lassman/The Post-StandardThomas Rawinski, a botanist with the U.S. Forest Service, measures a sapling at the Montezuma National Wildlife Refuge. Sarah Schoenberg, of the U.S. Forest Services, helps record the data.

Thomas Rawinski said botanists are generally not fond of white-tailed deer.

“Especially large numbers of them,” he said. “That’s because botanists are usually the first people to see the impacts. The average person looks at a forest and the trees and just doesn’t see what’s going on.”

What’s going on, said Rawinski, a botanist with the U.S. Forest Service’s Forest Health Protection Program, is that in many areas of New York and the Northeast “the deer are eating themselves out of house and home.

“In many cases, the regeneration of trees and other plants are severely compromised or even eliminated,” he said.

He cited a report released last year by the Nature Conservancy in which forests were randomly sampled across this state, using data supplied by the U.S. Forest Service.

“One third of those sites did not have sufficient regeneration, and reports strongly implicated deer browse as the main cause,” he said.

Rawinski, who was in the area last week following up on work he started last year at the Montezuma National Wildlife Refuge in Savannah, is working closely with U.S. Fish and Wildlife staff there. He’s also partnered with the state Department of Environmental Conservation at the northern end of the Montezuma area, and at Beaver Meadows State Forest in Chenango County.

At the latter location, DEC foresters have determined that browsing by deer is negatively impacting the 5,800-acre forest “beyond what traditional hunting and forest management can address.” Last year, the DEC issued a special Deer Management Assistance Program permit, which essentially gave the foresters there 110 location-specific, antlerless-deer tags to hand out to hunters in attempt to knock down the deer population during the regular hunting season.

The program is continuing this year.

Rawinski talked this week about what he does and why the average person should care.

Someone might say there’s enough forest for all the animals. Why not just let Mother Nature take care of her own.

White-tailed deer evolved as a very prolific herbivore. In the forest, they evolved with a whole host of natural predators. We humans have altered that ecosystem by removing most of the major predators. We humans have manipulated the habitat to the liking of deer.

Many experts agree that we have more deer in eastern America than in pre-colonial times. People have different reasons for wanting to control the size of a local deer herd — agricultural, Lyme disease or to reduce deer-car accidents. Mine is ecological.

Just what are you doing at Montezuma and other locales to study this?

Here (at Montezuma and elsewhere), I’ve set up 10-square-meter areas and 100-square-meter areas. We measure all the tree saplings in the bigger plots and we count and measure the height of everything in the smaller plots. The idea is come back each year to measure and count everything again to see if there’s any changes.

You talk about forest disintegration and forests not being able to regenerate. So what?

One has to look at a forest as a whole, as a thriving organism. A 40-year-old tree falls and nothing springs up to replace it. You have places like Letchworth State Park. It’s a real horror show over there, where studies clearly show what used to grow there and all the bio-diversity that we’ve lost because of deer

It’s not just the plants that are affected. These effects cascade throughout the ecosystem. Think about the pollinators, all the native bees, butterflies, skippers, the low-nesting birds — they have no habitat. I’m not just talking about such things out of thin air. There are places across the state you can go and see for yourself.

Why have you been called to the Montezuma National Wildlife Refuge? Too many deer here?

There is a controlled hunting program here, but the deer are hard to count. They’re very mobile animals. What we’re seeing quite often is that due to limitations of access, hunters aren’t getting into deep swamplands. Bottom line, there isn’t enough hunting to reduce the deer population to a level that allows the new trees to grow in certain parts of the refuge.

Be more specific.

There doesn’t seem to be an impact on the overall forest health, but in certain localized areas we’re seeing certain impacts that we’re closely monitoring.

For example, where Eastern red cedar grows on the refuge, the deer are suppressing (the new saplings). Just north of here in the (state-owned) Montezuma Wildlife Management Area, we started monitoring trilium (a flowering plant) and we’ve seen their numbers greatly reduced.

The DEC has also taken steps to protect an endangered tree species (Kentucky coffee tree) by trimming out the competing trees and putting fences around the young Kentucky coffee trees. You can’t do that, though, for everything.

You mentioned the browse line. What’s that?

That’s the area of the forest from the ground up to about 5 to 6 feet — the area that deer feed on. You can look out into a forest in some areas I’ve been to and see nothing growing in that zone, thanks to deer.

Is there a correlation between what deer are feeding on and the spread of invasive plants?

There are some invasives deer eat, and a disproportionate number that they don’t eat. They don’t like Japanese stilt grass, which is starting to invade this part of the world, and they don’t eat barberry because it’s so spiny.

They also won’t touch garlic mustard. As the desirable plants are trimmed out of our forests, it opens up the opportunities for the invasives to move in.

Your view of hunters?

Many view hunters as the heroes in all this — particularly bowhunters near suburban areas. Things like hiring sharpshooters to reduce deer herds are expensive. White-tailed deer hunting is extremely popular, it costs the community nothing and provides a low-carbon footprint meat for people.

Will there ever be a consensus on what we as humans should do to manage deer?

We all have our own opinion and we all own the resource. It’s a very challenging question. I see it as a matter of conservation, of looking at the land (and all its components) as a super organism that we want to keep healthy.

As we look around, is the super organism thriving — or are deer causing havoc to disturb that health? I would say in a variety of areas they are.

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