Fifteen years ago on a steep, rocky hillside I found a small patch of old growth hemlock, white pine and oak. Following that discovery I made several return trips, but haven’t been back in over a decade. Presumably the old time loggers didn’t cut the trees because a good teamster would have been careful not to take his horses into terrain where the risk of injury to them was high – they were his livelihood. This spot is near the mouth of a tributary to one of the largest streams in the area, where floating the logs to any of several sawmills eight to ten miles downstream would have been easy.
The lower slopes of this hillside were logged at least 150 years ago as shown by several old skid trails that were used to move the logs down to the stream.
Yesterday, one of the skid trails made for a pleasant hike uphill through a second growth forest that now, after all these years, has many large trees that many would consider “mature”. The skid trail ends well below the old growth; to see the large old trees then requires a scramble over moss-covered rocks and logs and clambering over or around fallen trees – on steep hillsides such as this, many trees succumb not to old age or loggers but to the force of gravity.
When I got to the old growth it was painfully obvious that all of the hemlock was dead or dying; the result of feeding by the invasive hemlock wooly adelgid. The hemlock wooly adelgid is a tiny insect that feeds by sucking sap from young twigs on hemlock. It has been killing eastern hemlock for many years, but has only been impacting hemlock in northcentral Pennsylvania for about a decade.
On the lower slopes, presumably due to more moisture, better soils and the younger more vigorous trees, most of the hemlock looked much healthier, even though adelgid can be found on most trees.
A short drive and a walk of about one and a half miles led to Jacoby Falls a pretty, although not spectacular, waterfall.