While helping Friends of Lincoln Park restore the forest, a University of Washington environmental-studies senior has also been studying one of the park’s thorniest issues: Off-leash dogs. Sam Timpe has been working with the local volunteers 15 hours a week since January, planting natives and pulling invasives.

Spending all that time in the park, he’s been able to observe dog owners and their pets, and while most follow the rules, he says the ones who don’t are responsible for more damage than you might think. He’s hoping for an “attitude shift” in the park, and hoping that people feel empowered to talk to those not following the rules, to say “please don’t do it,” to have a sense of community.

Restoration work is something you often won’t detect just with a casual glance. It’s a cleared spot, a small plant. “With all the people doing restoration work there,” Sam said, “to have a dog run through it and tear it, is kind of disheartening.”

Any individual dog, of course, wouldn’t do that much damage, he explains, but if he sees one every hour, ten times a day, 50 times a week, the cumulative effects add up.

From Sam’s research:

I did a study within Lincoln Park to get some baseline data on leash and trail compliance. I chose three different locations within the park (south open area near bluff trail, north open area west of soccer field, and the north parking lot) and at each location I conducted three 90-minute samples, one on a weekday morning, weekday evening, and weekend morning. I found that 59 of 239 (25%) of dogs were off leash. 55 of 239 (23%) of dogs were observed going into the woods (off trail, off grass). When excluding the north parking lot, I found that 38% of dogs are off leash and 29% are going into the woods.

The effects go beyond the “trampling of plants,” he explains. When that happens, it’s easier for seeds to disperse and the forest edge to break down. Those seeds are seldom desirable ones – instead, they’re the invasives, the berry-laden plants like ivy, holly, blackberries, cotoneaster.

And the giddily exploring pooch might spread them beyond the park – seeds can catch in their paws, and be carried far away.

One area that Friends of Lincoln Park is particularly concerned about is near the north parking lot. A restored area might look like a clearing – with the invasives removed, and the new native plants fragile and small – and that might seem to some like an invitation to make their own trails. Sam says he also sees people stop, let their dogs out for a quick dash or bio-break, and then move on.

What would he say to try to educate people, convince them not to do this?

Without the restoration work, he says, invasive plants will start to take over and start climbing up trees (think of all the ivy-covered trees you’ve seen). Eventually that weakens the trees, and a windstorm might be all it would take to bring them down. On the ground level, the invasives take over and nothing else can get established, so a “monoculture desert of holly and ivy” results, he explains. Take a look at the difference between a clump of native vegetation before cotoneaster removal, and after:

The value of a healthy urban forest? Priceless. He ticks off benefits: “Reduces stormwater runoff, improves water quality, captures and filters air pollution, provides wildlife habitat, aesthetically improves neighborhoods’ appearance …”

About the wildlife: Even if a dog doesn’t catch it, or eat it, it is a threat: “A lot of these animals, if you watch them for a while, they’re working on eating, building shelter, nests, on what it takes to survive. When you do have dogs chasing them, they have to expend a lot of energy on the chase, getting safe …maybe that next chase does it in, it’s tired. I found one study about shorebirds – having to avoid dogs chasing after them 12 times a day. Many were getting ready for migration. In another study, researchers walked through different areas (of a forest/park) with dogs on leash, with dogs offleash, without dogs … when humans were there with dogs, there was a 41 percent decrease in the amount of birds present. Birds are aware it’s a potential threat.”

So what’s the solution?

More parks specifically set up for off-leash dogs seems like an obvious idea, Sam says, but they’re not so simple to set up – grassy fields get muddy in the rainy season very fast; gravel can lead to runoff problems for nearby waterways.

He hopes that information and education – like this report about his volunteer activities and research – can help people be aware that dogs at least need to stay on the paths, and to share that awareness with others.

He’s working toward a research paper and presentation next quarter. And he’s well aware that dogs are the light of their humans’ lives … he’s just hoping a little enlightenment will help the forest and its inhabitants too.

Stay on the trail, or at least grassy edges and fields – it’s not grass they’re worried about. If it’s a native plant, don’t walk or run on it – salal, Oregon grape, red flowering currant, ocean spray, seedlings of evergreens such as Western red cedar, Douglas fir, Western hemlock, all types of ferns, snowberry … He could go on.

He’s been working on a spot near the bluff trail but hopes to see all the restoration areas thrive.

P.S. He’s interested in your thoughts, if you have a moment to comment.