Krupp: The Alburgh Dunes and Bog
As the cold advances, I like to reflect on favorite warm weather moments – like the trip I took this summer to the Alburgh Dunes and Bog on a tour sponsored by the Vermont Hardy Plant Club and led by plant biologist Liz Thompson.
First, we visited a stretch of rare sand dunes where we saw buttonbush and fresh water cord grass – more often found along the Atlantic shore. We also saw Champlain beach grass and the low-growing beach-pea – both rare plants that are remnants of the post-glacial era, when Lake Champlain was an inland estuary of the Atlantic Ocean. Unfortunately, poison ivy has invaded the dunes – so we had to be careful where we walked.
For 15 years, Moe Theoret was the park ranger of Alburgh Dunes. He recalls when they were being bulldozed to replenish the nearby beach. Protective vegetation was damaged when trees were being cut for firewood and beach visitors were walking on the beach grass. Today, protective fencing has been installed and the dunes are repairing themselves.
The 625 acre Alburgh Dunes became a state park in 1996. Its south-facing sand dunes are one of the longest beaches on Lake Champlain. Together, the beach and dunes make up what’s known as a barrier island, geologically similar to coastal formations more common along ocean shorelines. This barrier sits between the lake shore and a wetland bog - with beach and dunes both slowly migrating into and over the wetland. Large turtles and other wildlife are attracted to the Dunes - including coyotes, foxes, owls, deer, moose and bear.
There’s a layer of peat more than 26 feet deep in the black spruce swamp and bog, where we found sphagnum moss, pitcher plants, high bush blueberry, cotton grass, mountain holly, bog and sheep laurel, dwarf mistletoe and labrador tea. Core samples from the bog reveal a record of climate and vegetation dating back to the ice age. The swamp and bog are more typical of those found in the cooler Northeast Kingdom – and quite a contrast to the neighboring sand dunes.
Once, Lake Champlain was a salt water sea inhabited by whales. The sea flowed south, forming the dunes about 10,000 years ago. On nearby Isle La Motte, there’s a fossil reef some 480 million years old, containing some of the oldest corals in the world; corals that grew in a tropical sea.
I can almost feel the warm breeze as I contemplate this amazing place we call home.