Chesterton Tribune

Researchers urge less mowing at Sunset Hill Park to encourage plants, birds, amphibians, mammals

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The Porter County Parks Foundation on Thursday unveiled a biodiversity study of Sunset Hill Farm County Park that credited the park as one of the few preserved remnants of Northwest Indiana’s rich natural heritage.

Prepared by Dr. Spencer Cortwright of Indiana University Northwest, plant expert Sandy O’Brien and ornithologist Helen Dancey, the report recommends that park officials decrease mowing in Sunset Hill Farm’s grassy areas, use prescribed burns in the wooded areas, and reintroduce more native prairie grasses and wildflowers to enhance the farm’s habitat mosaic.

Foundation President Tim Cole said the biodiversity study, spearheaded by former park board member and geologist Dr. Mark Reshkin, is an important tool for park officials to use when planning the park for public use.

In a presentation Thursday, Cortwright emphasized that outside of the Indiana Dunes, very few sites are preserved in Porter County that contain the native habitats of savanna, prairie and wetlands. Other than Sunset Hill, the only such protected lands are the Taltree Arboretum and the Moraine Nature Preserve.

“We’re still very much behind the times,” Cortwright said, as he pointed to a map of the Chicago area that included many protected sites in Illinois.

He gave a historical perspective of Northwest Indiana’s natural areas, noting that about 25 percent of Lake and Porter counties was once wetlands and that a large prairie once stretched from Wheeler to the Indiana Dunes. The complex and diverse habitat is surprising, he said, since most other ecologically rich areas are in mountainous regions.

As he called for preservation of more land, Cortwright said conservationists are often criticized for being greedy in their quest for protecting as much land as possible. But because of urban sprawl and habitat destruction, ecologically significant lands outside the dunes are now rare, he said.

“We’re greedy over crumbs,” he said.

Cortwright also emphasized the importance of property owners, whether they own small parcels or large tracts of land, to plant native grasses and wildflowers. Native species are much more efficient than exotics at capturing nutrients, withstanding fire and drought, and providing food sources for wildlife.

He welcomed the renewed popularity of grasses, but said that most of the ornamental grasses people plant are from Asia, not native species. In addition, he said, many butterfly gardens contain non-native plants that, while attracting butterflies, don’t provide a food source for caterpillars.

He lamented the maintenance involved in lawns, including the push from fertilizer companies to chemically feed grass. “You never have to feed a natural area,” he said.

He also stressed that the more diverse plant habitat in one’s garden or in a park, the more diversity there will be in wildlife, resulting in a healthier food web.

The biodiversity study found that while Sunset Hill Farm’s pre-settlement habitat has been modified significantly, the 235-acre park is still home to an impressive array of species.

The report found, for example, that four areas in Sunset Hill Farm qualify as a “natural area,” meaning that the native plants are a good representation of pre-settlement times and for all practical purposes cannot be replaced. These areas are the small tract of woods near the playground, the wood and pond area at U.S. 6 and Meridian Road, the 20-acre field that includes the fen, and the Murray Woods.

The Murray Woods, the largest natural area in Sunset Hill, has been farmed and grazed with most of its shrub and trees non-native. Still, the area contains enough of the original native flora that it has a rating that makes it extremely rare in the Chicago region. Though less pristine than the best sites, it is “still a far better woodland than the best human team could create from scratch,” the report says.

The report strongly discourages the park department from mowing excessively in certain park areas, instead converting these areas to prairie and savanna.

“Many forms of wildlife will benefit from this conversion – the result being a more natural and full food web of animals,” the report says.

One of the areas where mowing needs to be reduced, the report found, is near the farm pond. The report notes that mowing so much so close to the pond eliminates wetland plants and encourages hordes of Canadian geese, which dislike tall vegetation next to ponds.

The report also found that Sunset Hill contains a diversity and abundance of small mammals, such as deer mice, voles and shrews, but that after mowing, the mammal population levels dropped markedly. The report noted that park staff reported that large predatory birds are common after mowings, probably because the small animals have less protective cover and are easier prey.

While small mammal populations sometimes “crash” naturally, it is rare that crashes of a variety of species occur all at once. “This suggests that mowing may cause populations to decline rapidly thereby making extensive periods where food is hardly available to predators,” the report says.

A survey of the bird species conducted by Dancey showed that 87 species use the park, of which 56 show signs of breeding. While this is considered a good diversity, the report also noted that it appears that bird species might be in decline at Sunset Hill.

The park contains five bird species that have suffered serious declines as a result of habitat destruction. These are the threatened sedge wren, which nested at Sunset Hill; Cooper’s hawk, sharp-shinned hawk and northern Harrier, all of which are species either endangered or of special concern; and dickcissels, which are rare in this area.

The report also strongly encourages that the planting of native species and restoration projects, like the pulling of the highly invasive garlic mustard, should be done in concert with the public.

“These activities will unify many diverse citizens of all ages to a common cause,” the report concludes. “The emotional and physical well-being of citizens will be enhanced both during restoration and the enjoyment of the results. As well, wildlife will be enhanced. This is a win-win situation to which we should strive.”



Posted 3/22/2002