Old Growth Recovery in Kentucky
Old growth. The term itself is evocative, bringing to mind images of forests primeval, of giant trees steeped in beauty and mystery, and of places where wildness and wild things tell an ongoing story reaching back into timelessness. Ecologically speaking, “old growth” is a varied and complex term with no single definition encompassing the wide range of conditions and considerations associated with its use. Vagaries notwithstanding, we can say with some confidence that, prior to Euro-American colonialism and resource exploitation, the landscape of Kentucky was dominated in most places by old growth forests.
Today most of our discussions regarding old growth consist of identifying, studying, and protecting remnants that meet various criteria – usually a combination of canopy age and a history minimal human disturbance. But as time moves on and natural disturbance and human folly (hemlock wooly adelgid, for example) take their toll, is it inevitable that the last traces of old growth will vanish from the landscape? Or is there more can we do?
Among the definitions of old growth is that of “secondary old growth.” This term describes forests that, having been cut at some point in the past, have had time to redevelop structural and functional old growth characteristics. For most forests in Kentucky, this means some combination of large diameter trees, a multi-age, multi-layered canopy, and snags and down trees of various diameters (particularly very large diameters) and levels of decay. These structural components create a rich habitat for many species, including fungi, birds, herptiles, and mammals both big and small. Black bears in the southern Appalachians, for example, have been shown to prefer denning in hollow trees over 3 feet in diameter – an uncommon condition in heavily managed forests, but characteristic of old growth and older second-growth forests over 150 years old. And as very large trees fall naturally from the canopy they create substantial patches of early successional habitat important to many species, and initiate natural forest regeneration at the “patch” scale, rather than the stand or watershed scales often associated with logging.
So how do we restore old growth? What old growth characteristics do we consider most important? What structural and biological indicators will help us identify priority areas, and at what scale? Can silviculture play a role, or is this antithetical to the whole endeavor?
It is true that some species have been irretrievably lost, and long-term, landscape scale ecosystem dynamics have been dramatically altered. But what we know about forest ecosystems is that they have always been in a state of flux. Patterns of species dominance, rates and types of disturbance, and climatic influences make the natural conditions of the past a moving target. Still, historical documents and insights from the ecological sciences point us toward a vision of landscape restoration approximating a historical range of conditions, of which old growth forest communities play a significant part. As such, old growth restoration must go hand-in-hand with other efforts to restore native communities and ecosystem function on our public and other conservation lands.
In the coming months, we'll begin to explore in detail many of the questions and possibilities that pertain to the recovery of the Great Forest that was and could be again.
Today most of our discussions regarding old growth consist of identifying, studying, and protecting remnants that meet various criteria – usually a combination of canopy age and a history minimal human disturbance. But as time moves on and natural disturbance and human folly (hemlock wooly adelgid, for example) take their toll, is it inevitable that the last traces of old growth will vanish from the landscape? Or is there more can we do?
Among the definitions of old growth is that of “secondary old growth.” This term describes forests that, having been cut at some point in the past, have had time to redevelop structural and functional old growth characteristics. For most forests in Kentucky, this means some combination of large diameter trees, a multi-age, multi-layered canopy, and snags and down trees of various diameters (particularly very large diameters) and levels of decay. These structural components create a rich habitat for many species, including fungi, birds, herptiles, and mammals both big and small. Black bears in the southern Appalachians, for example, have been shown to prefer denning in hollow trees over 3 feet in diameter – an uncommon condition in heavily managed forests, but characteristic of old growth and older second-growth forests over 150 years old. And as very large trees fall naturally from the canopy they create substantial patches of early successional habitat important to many species, and initiate natural forest regeneration at the “patch” scale, rather than the stand or watershed scales often associated with logging.
So how do we restore old growth? What old growth characteristics do we consider most important? What structural and biological indicators will help us identify priority areas, and at what scale? Can silviculture play a role, or is this antithetical to the whole endeavor?
It is true that some species have been irretrievably lost, and long-term, landscape scale ecosystem dynamics have been dramatically altered. But what we know about forest ecosystems is that they have always been in a state of flux. Patterns of species dominance, rates and types of disturbance, and climatic influences make the natural conditions of the past a moving target. Still, historical documents and insights from the ecological sciences point us toward a vision of landscape restoration approximating a historical range of conditions, of which old growth forest communities play a significant part. As such, old growth restoration must go hand-in-hand with other efforts to restore native communities and ecosystem function on our public and other conservation lands.
In the coming months, we'll begin to explore in detail many of the questions and possibilities that pertain to the recovery of the Great Forest that was and could be again.
