Thinning Overcrowded Young White Pines at Crystal Spring Farm

By Cora Spelke (BTLT summer intern) and Steve Pelletier (certified wildlife biologist, licensed Maine forester, and member of BTLT’s Advisory Council)

If you’ve ever walked Crystal Spring Farm’s (CSF) elaborate system of trails, then you’ve had the opportunity to experience its differing forest types, including many dominated by varying mixes of white pine, red oak, and numerous other native hardwood and softwood trees. Each of these species, together and alone, provide a broad variety of important ecological landscape functions and social attributes that in turn support two of CSF’s primary management goals, i.e., healthy, diverse wildlife habitats, and active and passive recreation. In addition, each individual tree, through photosynthesis, actively sequesters and stores carbon throughout its entire system, including the woody fibers and mycorrhizae found deep within its roots. Recognition of this innate phenomena is a fundamental – and increasingly important – means of offsetting the devastating threats of global climate change.

The ability of forest stands to support natural functions is dependent on the general health and conditions of trees within a stand, and include varying factors such as species type, average height and diameter, stem density, and overhead canopy closure. In certain circumstances, tree numbers – or the stand density per unit area – will become so high that the growth rates of individual trees are stunted due to excessive competition for available sunlight, soil moisture, and growing space, thus not allowing trees to grow to their full potential. These overcrowded conditions also limit individual tree vigor which in turn contributes to poor health and increased opportunities for the spread of tree disease and insect damages within the stand.

One area on the Crystal Spring Farm trails that displays such conditions can be found at the beginning of the Blueberry Loop. As seen in the picture to the left, the sides of the trails are full of young (~12-14 years old) white pine trees all growing right next to each other. In order to increase the health of the forest and the trees, some of these young pines need to be removed to allow more growing space for the remaining trees to grow. One of the tasks undertaken by BTLT summer intern, Cora Spelke, is to head out to the CSF trails about once a week to begin thinning out these younger portions of the forest stand. The removal of individuals will specifically focus on those that are poorly formed or already displaying various signs of disease (e.g., white pine blister rust) or insect damage such as the white pine weevil. The most vigorous, healthiest young pine will be left in place with a minimum six to eight feet of spacing around each tree at this point in time. A future thinning in approximately 5 to 10 years would then further increase the spacing of trees at that time, further increasing the value and health of the forest stand. In that way, we expect to improve the ability of this stand of timber to provide quality wildlife habitat, to enhance its aesthetic appeal to recreational users, and to substantially increase the ability of the stand to help reduce our carbon footprint. These efforts are being conducted under the supervision of Steve Pelletier, a certified wildlife biologist, licensed Maine forester, and member of BTLT’s Advisory Council.