Gap Dynamics or More Than That? Long-term Development of Mixed Hardwood Forests

Abstract

It is not unreasonable to think that sustainable management of Northern Hardwood Forests would be partly informed by long-term data on forest dynamics. Most measures and observations of forest dynamics are set by grants (3-5 years), the careers of scientists and managers (20-40 years), or, less frequently, long-term plots approaching 100 years or so in age. While these data and observations are incredible and useful, they represent only a fraction in the lifetime of most trees and far less than what I’d estimate the length of forest generation to be. We have analyzed tree-ring records from local to subcontinental scales that cover the three to five centuries in mixed hardwood forests. In no way do these analyses supersede the great data mentioned above. They do color in the natural and understandable gaps in knowledge of forest processes and dynamics. We have identified climate as one potential synchronizer of forest dynamics over subregional scales that, together with gap dynamics and many other types of drivers, helped to create today's old-growth forests. Put another way, while the classical theory on the cyclical nature of Beech-Birch-Maple gap dynamics in Northern Hardwood Forests are likely a very real phenomenon, other drivers at longer time scales and broader scales might suddenly push the trajectory of these forests at various points in time into new structures or compositions.