CADILLAC — Those trees in the big commercial parking lot didn't happen by accident. Neither did the ones that line the highway, blocking your view of a business tucked behind the branches.

Somebody planted them. And it's likely, depending on where you are, that somebody told them they had to.

Clam Lake Township recently passed its zoning ordinance, and within the ordinance, there's a list of tree species that can be used for landscaping screening.

Muncipalities with screening requirments aren't just after the "rustic" look. The trees have a job to do.

“In addition to beautification, there are sometimes vegetation screening requirements to separate uses," explained Claire Karner, the planner who worked with Clam Lake Township on its new ordinance. The trees give you a clue, then, that one chunk of land is for one purpose and another chunk of land is for another purpose; such as where subdivisions abut retail spaces.

Trees can also help block light pollution, according to Clam Lake Township Zoning Administrator Cindy Warda.

Other times, trees have an environmental job to do.

You're familiar with the concept of a shade tree. Well, in parking lots, that's their job: providing shade and helping the lot cool down.

Trees can help reduce the "heat island effect," Karner said.

Other landscaping requirements help protect water.

Creative landscaping, particularly in "Planned Unit Developments" (mixed-use) and new subdivisions, can help prevent water run-off, said Robert Hall, the planning and zoning administrator for the Wexford Joint Planning Commission, which handles zoning for 11 townships in Wexford County (the commission is not part of county government).

Native plants do the job especially well.

Dru Mark-Wilson, Huron Pines Americorps member serving as a conservation technician

Native plants have a more extensive root system than non-natives, said Dru Mark-Wilson, an Americorps member serving as a conservation technician for Missaukee Conservation District. The more extensive root system stabilizes the soil. Stable soils filter water better.

And that means less nutrients that could hurt lakes wind up in the waterways.

Around lakes, municialities with zoning ordinances pick which shoreline guidelines from the Department of Environment, Great Lakes and Energy they want to adopt.

The "greenbelt" around lakes can be strictly or less strictly regulated. Some townships leave it at keeping buildings away from the water and requiring septic systems to be farther away, while others call for landowners to plant—or at least not cut down—trees and other native plants.

Clam Lake opted for fewer regulations, while the Wexford Joint Planning Commission says trees of a certain size should not be axed (unless dead or diseased).

Some non-native plants do make it into the zoning codes, and not because they've been banned. Clam Lake Township's ordinance, which is based on an older zoning ordinance from when Wexford County provided zoning, specifically encourages landowners to plant certain kinds of non-native evergreens.

While the state regulates invasive species—there are some you aren't allowed to possess under law (NREPA part 413)—not every non-native plant is a bad one.

That's because not every non-native plant is invasive, Mark-Wilson said.

Invasive species, however, can grow quickly, out-competing native plants, while failing to grow extensive root systems. That means that even as the plant is using up space in the soil, it's not doing its part to keep the water clean. 

Cadillac News