Lawn-to-Lake Shorelines – No Longer Ecologically Smart
by Paul Radomski and Russ Schultz, MN Department of Natural Resources.
Many people like to look across a beautiful lake or enjoy nature by fishing or boating. You see evidence of this on the highways heading north out of the Twin Cities on Friday afternoon. Visitor surveys note that the top reason people visit this area is to escape to natural areas.
All of us, personally and as a community, can protect our lakes and shorelines through individual acts and through shoreland development standards and ordinances that regulate development around our lakes.
Recent research has shown that current shoreland rules are not providing enough protection. There are approximately 225,000 residential lake lots in Minnesota. While most lakeshore owners leave or restore native vegetation along the shore, more than 25 percent have a mowed lawn down to the lake. The cululative impact of those lawns is substantial.
Biologist have found that trees, shrubs, and the forest understory near the shore declines over time on developed shoreline. This change in lakeshore habitat leads to different bird communities. Common suburban-style birds like chickadees, blue jays and grackles replace the uncommon species of special concern, warblers and vircos, along developed shores. Loss of trees along shore means fewer trees fall into the water. Fallen trees provide habitat for fish. Biologists have determined that this loss of trees due to development will negatively affect fish for centuries.
Jeff Reed, a biologist studying crappie nesting in three Alexandria area lakes, found only 24 of 897 nest sites near developed shoreline. Crappies were selecting undeveloped shorelines for their spawning and nesting activity at significantly higher rates. Why? Nearly 90 percent of the crappie nests were near bulrushes, an emergent plant that’s sensitive to recreational activity and often declines near developed shores.
Hydrologists and chemist have also found interesting differences with the lawn-to-lake style of shoreline compared to a native vegetated shoreline. Rainwater runoff from lawn-to-lake shorelines was measured to be 5 to 10 times higher than forested shorelines. Lawn-to-lake shorelines allow seven to nine times more phosphorus to enter the lake than a more natural, native vegetated shoreline. Phosphorus is a plant nutrient. More phosphorous in a lake means more algae, resulting in lower water clarity.
A lawn down to the lake is bad. It diminishes fish and wildlife, reduces water quality, and degrades the scenic quality of the lake. Because of this, many people are seeking higher shoreline vegetation standards that communities can add to their ordinances. For example, new standards could require lakeshore owners to preserve or establish a native forest buffer along the lake. The timber harvest industry and farmers must leave vegetative buffers along lakes to protect water quality. Why not require the same of lakeshore owners?
Question on Weedrollers
Q: Weedrollers have become a popular tool for eliminating unwanted vegetation along the shoreline, especially in the Brainerd Lakes area. What sort of problems do they cause for fish and water quality?
A: Mechanical devices, such as weedrollers, are commonly used to control aquatic vegetation in public waters and their use is regulated by the DNR through the issuing of permits. Not all sites are suitable for the operation of these devices, however. Although they can be an effective method of controlling vegetation, these machines can have a negative impact on lakes, which is an area of concern when it comes to lake management. The potentially harmful affects of the loss of aquatic plants are felt by a wide variety of species, including waterfowl, invertebrates, amphibians and fish. Specifically, weedrollers can decrease water clarity by displacing sediment and destroy fish spawning beds and nursery areas, and potentially impact recreational activities. Lakeshore owners should be aware of these tradeoffs when considering using such devices. A proper permit must be obtained before using any mechanical vegetation removal device.
Reprinted from th Minnesota Lakes Association Lake Bulletin, 8-10-05
PROTECTING YOUR SHORELINE
by Julie Lindner, Soil Conservation Technician
I’ve heard many people say, “I’m only one person; will what I do really make a difference?”
What happens to a lake and its shoreline is the cumulative effect of all the lake users and shoreland owners. In addition, lakes have a watershed called a lakeshed, which is all the water that drains into the lake from the surrounding landscape. Some lakesheds are large and contribute a lot of water and potential pollutants to the lake and some are smalll with relatively little input from the watershed users. Fortunately, the cumulative effect of the lakeshore owners can have a positive impact on the lake.
What can you do? Many lakeshore owners are converting a portion of their traditionally mowed shoreland area back to native vegetation. Native plants require minimal maintenance once established and improve the value of lakeshore property. Instead of mowing, they also have more time to enjoy the reasons why they own lakeshore; like boating, fishing, swimming, bird watching etc.
Native plants provide habitat for many wildlife species like birds, butterflies and mosquito-eating dragonflies; dead or downed trees can provide perches for turtles, blue herons, and ducks. If a dead or fallen tree does not pose a hazard, think about leaving it to provide habitat for animals above the water and organisms below the water.
Many shorelines contain wetlands and contain diverse species of vegetation and provide habitat for many critters, including insects, frogs, and other small organisms that are eaten by fish like the Northern pike. Northern pike spawn among the aquatic vegetation.
Ash, oaks, willows, white spruce, red and white pine trees grow along lakeshores, as well as shrubs like dogwoods, chokeberry, and elderberry. Native wildflowers, such as: Boneset, Blue vervain, Golden alexanders, Blue flag iris, and Canada anemone grow among sedges, rushes and nataive grasses.
For a listing of native plant suppliers or for more information, please contact the Pine SWCD office at 320-384-7431