Succession

Beaver dam at Baltimore Woods

It's not easy being a beaver (Castor canadensis).  A beaver is a squatter by all rights, and there are not many places left where he can make his home without being evicted.  But there are a few places still left, protected places, that allow a beaver and his family to do what they innately need to do: dam a river or stream, gnaw away and knock down trees so they can build a dam and den.  I went to visit such a place in Baltimore Woods this past week with my students.  Baltimore Woods is a protected property, 182 acres of land open to the public and and owned by the Central New York Land Trust.   Because it is protected, so are the flora and fauna residing there.  Baltimore Brook, a meandering stream, works its way through the property and provides the perfect backdrop for beaver life.

What made the field trip with my students so worthwhile is that we were able to view a beaver meadow -- the remnants of an abandoned beaver dam -- and just downstream from there a newly built beaver pond. It was a perfect lesson in succession, the changes in a landscape over time due to physical or biological interventions.  In this case, the beaver is the intervener.

Beavers set up home once they build their dam and ensure a pond environment that will protect them over the winter months and provide them with a place to store their cache of twigs for food.  After the dam is built they work on building a home where they can raise their kits, or litter of young.  After a few years if the host of trees available for consumption dwindles they move on to a new site downstream, like they have done at Baltimore Woods.

What they leave behind is a legacy of a meadow, and a new generation of plants that would have never appeared if it hadn't been for their work.