By Gray Merriam, PHD., DSc., Prof. EmeritusLandscape Ecologist
A recent study by forest ecologists at Yale University reexamined the widespread notion that leaving trees unharvested in the forest was the best way to keep carbon dioxide (CO2) out of the atmosphere, thus preventing climate change (Frontiers in Ecology and the Environment, May 2014 and see J. Sustain. Forest. 2014).
Researchers at Yale's Global Institute of Sustainable Forestry pointed out that most earlier studies had not accounted for the CO2 being added to the atmosphere by the processes of making concrete or steel to substitute for wood in building construction. Earlier studies also failed to consider the uptake of CO2 as harvested forest was regrown. When these amounts are included, using wood from carefully harvested forest may be better for the environment.
Most earlier studies also did not go beyond just the CO2 accounting. Their attempt at "full-cost accounting" did not include the values of biodiversity and other forest values that are controlled by forest management.
Earlier CO2 accounting in forestry has been biased by the tacit assumption that the most desirable forest type was homogeneous "old growth" rather than a mosaic of forest structures and functions.
A fresh view is that we have the technical tools and if we devise appropriate management policies, forest harvesting and the use of engineered wood products in building construction could reduce CO2 input to the atmosphere and enhance biodiversity and other forest values.
Gray Merriam, PHD., DSc., Prof. Emeritus Landscape Ecologist