The mild temperatures and limited snowfall that the Adirondacks have experienced this winter season have failed to establish the usual snowpack that blankets the region by this time of year. While a substantial covering of snow provides numerous recreational opportunities for outdoor enthusiasts, it also serves as an essential fresh water reserve to supply the many brooks, streams and rivers across the Park with water when spring arrives during March and April.
With the first few thaws of late winter and early spring, much of the water produced from melting snow flows over the surface of the still frozen ground. This water quickly moves down hillsides and creates small, seasonal water courses on the forest floor. As these tiny tributaries merge and empty into larger, more permanent streams, the level of the water increases, along with the strength of the current.
When flowing over the carpet of dead leaves and needles in our woodlands, this water inevitably disturbs and collects an array of organic matter. The influx of such nutrient enriched water into our streams and river systems is vital for nourishing the many aquatic invertebrates that thrive in flowing water, and which are just awakening from their winter dormancy in the still frigid waters.
Black fly larvae, for example, spend the winter attached to the surface of rocks and logs at the very bottom of a body of flowing water where there is a rich supply of dissolved oxygen. With the increase in the strength of the current during late winter and early spring, these tiny, dark entities begin to feast on the wealth of microscopic matter swept into the water from the melting snow and resume their periods of growth and development.
As spring progresses, the ground starts to thaw, and the water produced from snow begins to seep directly into our porous soil. This water helps to recharge the water table of the area and becomes available to the root systems of the trees and ground plants of our forests which are starting to awaken from their winter dormancy.
Our normal snowpack is also essential to the formation of vernal pools of water that develop in numerous depressions on the forest floor. As the soil in many areas becomes saturated, water eventually collects in small, localized basins and typically remains for a few months until the warm and dry weather pattern of late spring and early summer develop.
These shallow, seasonal bodies of quiet water are ideal as breeding sites for numerous amphibians, including the wood frog and various species of salamanders. Pools of water from melting snow are also used by many species of mosquitoes for the development of their larvae. Eggs laid by female mosquitoes during the summer in dry depressions sit throughout the winter in the frozen soil. When water fills these places in spring, the eggs hatch and the aquatic larvae then have the opportunity to feast on the abundance of organic matter that is carried to these sites and settles in these basins.
March in the Adirondacks tends to be our snowiest month. It is the time of the year when moisture laden weather systems from the Gulf of Mexico come up the east coast and become energized by an infusion of cold, arctic air. This results in heavy precipitation events which are usually in the form of snow. This year, the orientation of the jet stream has not been favorable for such major snowstorms to develop. The la Niña weather pattern, coupled with a very positive arctic oscillation, has prevented cold air from plunging from the polar region into the mid-latitudes of our continent. Even Alberta Clippers, which are responsible for regular bouts of 2 to 4 inches of snow, have failed to form and track across our region this winter season. Similarly, lake effect snow events have been few and far between in this persistently mild and relatively dry weather pattern.
I have lived in the Adirondacks too long to know that the weather can change overnight, and a prolonged snow free period can quickly be replaced with a continuous series of blizzards. A substantial snowpack in our mountains is of vital importance to a healthy ecology in spring. The lack of a fairly deep base at this time of year, coupled with the long range forecasts of continued mild and storm-free weather, however, is making me a little nervous.