The countless miles of old stone walls which criss-cross New England’s woodlands have certainly out-lived the 19th-century farmers that built them. Many have persisted well into modern times, long after the tradition of an agricultural society has diminished and abandoned fields have been replaced by sprawling second-growth forests. But even these long-lived reminders of the old days will eventually come crumbling down.
The photograph above demonstrates a few of the natural forces that tug and pry at old stone walls every year (many of which can be directly observed while hiking in the forest). Snowfall, and the freeze-thaw cycles that occur during colder months of the year, are constantly weakening the settled structure of these walls. Water swells and contracts during these times, creating a hydraulic force that wrenches individual stones out of place and even degrades the matrix of minerals and molecules that compose each individual rock.
Trees that come crashing down upon these stone structures can do damage much faster than seasonal shifts. Even if the affected area of the wall doesn’t instantly fall apart on impact, the weight of the leaning tree trunk undoubtedly puts added stress on the stacked stones and contributes to a quicker collapse.
These represent only two factors that are contributing to the slow demise of New England’s stone walls. Tree roots can grow beneath the foundation of the walls, causing them to shift and topple. Foot traffic, both by hikers and woodland creatures, inevitably promotes shifts in the stacked stone. Erosion resulting from snow-melt and rainwater run-off further loosens the foundation.
While there is little doubt that most of these stone relics will remain standing well beyond our own lifetime, they will all be leveled in coming decades and centuries as the forces of nature slowly take their toll. Eventually each of these stacked structures will flatten out, creating wide bands of loose stone that contour the path of the original wall. From there, the same forces that brought them to the ground will begin to scatter the crumbled building blocks further and further away from one another.
For over 200 years, the agrarian way of life defined both the people and landscape of the Northeastern United States. But just as their abandoned farms and pastures eventually disappeared beneath forests, a day will come when the old stone walls beside which we hike today have been toppled and redistributed so thoroughly that people will probably forget that they were even there.