Fri July 6, 2012
The Changing Forest
A recent 10-year update to US Forest Service “Forest Inventory and Analysis” data reveals that New Hampshire now has a slightly higher percentage - 85% of the state now forested. Yet just as our human population is aging – a so-called “Silver Tsunami” – our forests are likewise aging. More than half the timberland in NH - 57% percent - is older than sixty-one years old.
As forests age, they change in composition. A higher percentage is now shade-loving hemlock, beech, yellow birch and red or sugar maple. While many people think older forests and larger trees sound great, there are species of wildlife AND TREES dependent on young forest conditions.
Data reveals only 13% of the State’s forest is less than 40 years old. Seedlings, saplings and small-diameter, brushy forests of sun-loving trees: paper birch, pin cherry and poplar are less common. These “pioneer species” established on abandoned farm pastures or in large clearcuts greater than 10 acres. They cannot establish in partial shade. They require large openings to regenerate and survive. Think “shopping mall parking lot” size only without asphalt! Large open clearings sustain hot, dry micro-climates these trees need to establish, compete and thrive.
Even-aged timber harvests – clearcuts - have fallen out of public favor. Some speculate that reticence to re-create the conditions favored by young forests of sun-loving pioneer trees will impact the abundance of our State Tree: paper birch. Healthy forests comprised of different ages, sizes and tree species are analogous to healthy human communities with diverse age profiles.