© 2013 John Wiley & Sons Ltd
Edited By: Steve Long
Impact Factor: 4.714
ISI Journal Citation Reports © Ranking: 2012: 2/78 (Agronomy); 8/81 (Energy & Fuels)
Online ISSN: 1757-1707
Associated Title(s): Global Change Biology
Effect of forest management on CO2 emissions and energy use
Bioenergy production is often considered to be carbon neutral because the combustion of biomass releases the same amount of carbon dioxide (CO2) as was captured in its growth; however, this is an oversimplification of the life cycle of bioenergy production. There are many processes involved from planting and harvest to transportation, some of which require fossil fuels. For example, fossil fuels are required to run equipment used for biomass harvesting and transporting feedstock and biofuels.
Routa and coauthors looked at the integrated production of timber and energy biomass from forests. Using a life cycle analysis/emission calculation tool, they estimated net energy balance and net CO2 emissions of Norway spruce and Scots pine plantations. The plantations experienced different management regimes encompassing the timing and intensity of tree thinning and the number of times fertilizer was applied.
The tool allowed the authors to calculate two measures of the impact of wood energy production on the environment: energy balance and CO2 emissions per unit of energy. The energy balance is the difference between the energy produced per hectare of forest and the energy necessary to produce it. CO2 emissions are calculated from the carbon uptake in tree growth and the carbon emissions from management and harvesting, decomposition of soil organic matter and burning of energy biomass.
The authors found that the optimal management strategy for low CO2 emissions per unit of energy was to plant at high density and apply fertilizer three times during the rotation. In addition, the fossil fuel energy consumption and related CO2 emissions related to the forest operations, including the production and application of fertilizer, were small in relation to the increased potential of energy biomass. The authors conclude that intensive management for timber and energy biomass decreases CO2 emissions in energy production.
Routa, J., Kellomäki, S., Kilpeläinen, A., Peltola, H. and Strandman, H. (2011), Effects of forest management on the carbon dioxide emissions of wood energy in integrated production of timber and energy biomass. GCB Bioenergy, 3: 483–497. doi: 10.1111/j.1757-1707.2011.01106.x