Salicicola Articles

Exploring Frost Pockets in Myles Standish Forest

We have always observed that Myles Standish is an entire different universe in Massachusetts, but we now can testify that frost pockets, or frost bottoms, are yet another hidden world within this universe. When viewing a frost pocket, you can't get rid of the impression of looking down onto a tiny tundra fragment hidden amidst the pitch-pine forest. The pink shrubs framing the view are scrub oaks, for which the time has stopped in April. In mid-June scrub oaks are still trying to produce leaves and catkins. A single branch of this oak has managed to leaf out under the protection of a small pine; otherwise the oak remains in the early spring phase.

Seasons are mixed here—just as it happens in the mountains near permanent snow banks. While scrub oaks are still celebrating spring, bracken ferns beaten by the frost look autumnish. At some spots, however, bracken has already sent out a second generation of fronds. Hillside blueberry (Vaccinium pallidum) produces a small-leaf form here and thus becomes difficult to recognize. Some of its shoots give it away, as they remain normal. We were glad to discover that dwarf upland willow (Salix tristis or S. occidentalis) has not been entirely pushed to the roadside in the park, as we had thought before, but actually produces large clones in the pristine habitat of open frost pockets. Black oatgrass, Piptochaetium avenaceum (or Stipa avenacea), a watch-listed grass, also takes advantage of these unique areas free of trees.

Of all woody plants in Myles Standish, the most frost tolerant one appears to be, surprisingly, black cherry, whose dense groves descending to frost pockets look rather optimistic and bold in comparison with feeble scrub oaks and pines. Another, creeping cherry (Prunus pumila) forms large prostrate patches, like this one in the center of the frame. An interesting native thistle, pasture thistle (Cirsium pumila) is a plant of open sandy habitats. It is a biennial forming a rosette during the first year. We had never found a wood lily (Lilium philadelphicum) in Myles Standish—not until we started exploring frost pockets. Not all of the lilies will have a chance to bloom and set seed, as frost pockets are a favorite daytime hiding spot for deer, and lilies are their favorite plants. We did not photograph those deer that we frightened off during our walks, though we have a picture of a recently used hiding spot. Users of frost pockets that are even less welcomed than deer are drivers of off-road vehicles, who have produced multiple illegal routes across pockets. This motorbike trail has damaged a large creeping cherry patch and crossed a lily spot. Bikers also inflict damage to frost pockets in a more intricate way, though this kind of harm is not less disastrous. On their wheels, off-road vehicles bring along seeds of invasive plants! Apparently, this is the way reed canary grass has made its way from contaminated fields to bikers' trails and then right off trails, to otherwise undisturbed vegetation of frost pockets. The DCR cares of the vulnerable habitat by taking down "encroaching" pines and blocking the motorcycle routes with produced debris. The DCR employees leave their own traces here... However, frost pockets take good care of themselves. Young pitch and white pines can barely survive here. A pine usually forms a compact bush, as its leader becomes damaged by the frost, and never becomes a tree. Thus frost pockets sustain themselves. Yet their stability much depends upon the stability of the climate, populations of wild animals, and amount of direct human disturbance. With the population of deer on the rise, accelerated climate change, and off-road vehicle pressure, frost pockets are becoming vulnerable.

White and even pitch pine are not really compromising the frost pockets health in any significant way. Meanwhile, there is indeed a tree in MSSF capable of successful colonizing frost pockets and feeling at home there! This is Norway spruce, a tree deliberately introduced to the Forest and now rapidly becoming a problem. Generally Norway spruce appears to be not well suited for warm summers and unsteady winters with sporadic snow cover in southeastern Massachusetts. However, in frost pockets it finds much more favorable situations and lack of competition from the native pines! Norway spruce has been already deemed invasive in some eastern US mountainous states, including TN, VA, and WV, where the climate is generally more suited for it. In the unique microclimate of MSSF frost pockets, its expansion can be just as bad!

Finally, a major threat for the frost pockets comes from development. One might think the territory of a state forest must be protected; however, there is an entity exempt from all restrictions including the Wetland Act and state land sovereignty. These are power transmission companies. Many frost pockets in MSSF with all their treasures happen to occur right along the major high-voltage line crossing the Forest; meanwhile, NStar has recently announced the intention to significantly widen this line in order to install additional electric poles by 2012. It is yet impossible to tell how much damage the frost pockets may suffer. Much depends on the upcoming decision as to on which side the power line is going to be widened.

Against such a background (construction, offensive bikers, invasive plants), the deer damage appears negligible... Will the frost pockets make it to the 22nd century? They should be protected as a unique natural feature by a legislation act similar to Wetland Act.

Irina Kadis, photos Alexey Zinovjev (19 July — 24 October 2010)