Krupp: Riparian Buffers

May 29, 2015

The Intervale Conservation Nursery in Burlington was founded in 2002 and is dedicated to growing native, locally sourced trees and shrubs for riparian restoration projects throughout Vermont.

A riparian buffer is a vegetated area - a "buffer" strip - near a stream or river that provides shade and protection from the impact of flooding and helps to stabilize an eroding bank. It's made up of young native trees, grasses, flowers, and shrubs that line the stream banks. The trees provide perching places for birds, and cast their shade on the water - keeping it cool for fish and frogs. They also provide seasonal blooms and autumn color to beautify the landscape while attracting butterflies.

Mike Inglis manages the Intervale Conservation Nursery, and he tells me that eleven thousand cuttings of native shrub willows, red and silver maples, birch, elm and red osier dogwoods are already being grown in the greenhouse. When these young cuttings send out roots and shoots, another twelve thousand cuttings will be planted in the greenhouse for subsequent plantings . The nursery grows about 40,000 trees a year.

It's a two to three year cycle from the greenhouse to planting sites. The conservation nursery covers seven acres of flood plain soil near the Winooski River. The trees are raised without chemical fertilizer or pesticides. Cover crops are also planted on the nursery grounds. When the Intervale flooded during Hurricane Irene, trees in the fields of the nursery were underwater for five days and emerged just fine.

In 2014, 23,000 trees were planted on 90 acres of riverside conservation projects in Vermont. In the summer of 2014, 4,000 bare-root stems were loaded onto backpacks and carried to a planting site on the Little Otter Creek in Addison County. After Hurricane Irene, 80,000 trees were planted along rivers and streams in northern Vermont. The trees were mostly willows and dogwoods plus maples, oaks, and birches. Trees and shrubs were used in a river bank landscape after a dam removal project on the Wells River in Groton. This work was in conjunction with the Connecticut River Watershed Council.

Now that weather patterns are being affected by climate change, the New England region is seeing a definite shift toward heavier storms that deliver several inches of rain in a single day, making the flood and erosion "insurance' provided by a riparian buffer zone more important than ever.