Life cycle assessment (LCA) was utilized to analyze the global warming potential (GWP), or carbon footprint, and associated costs of the production components of a field-grown, spade-dug, 5 cm (2 in) caliper Cercis canadensis ‘Forest Pansy’ in the Lower Midwest, U.S. A model production system was determined from interviews of nursery managers in the region. Input materials, equipment use and labor were inventoried for each production system component using international standards of LCA. The seed-to-landscape GWP, expressed in kilograms of carbon dioxide emission equivalent (CO2e), was determined to be 13.707. Equipment use constituted the majority (63%) of net CO2-e emissions during production, transport to the customer, and transplanting in the landscape.
The model was queried to determine the possible impact of production system modifications on carbon footprint and costs to aid managers in examining their production system. Carbon sequestration of a redbud growing in the landscape over its 40 year life, weighted proportionally for a 100 year assessment period, was calculated to be −165 kg CO2e. The take-down and disposal activities following its useful life would result in the emission of 88.44 kg CO2e. The life-cycle GWP of the described redbud tree, including GHG emissions during production, transport, transplanting, take down and disposal would be −63 kg CO2e. Total variable costs associated with the labor, materials, and equipment use incurred in the model system were $0.069, $2.88, and $34.81 for the seedling, liner, and field production stages, respectively. An additional $18.83 was needed for transport to the landscape and planting in the landscape and after the 40 year productive life of the tree in the landscape, another $60.86 was needed for take-down and disposal activities.
Forest biomass supply chains in Ireland: A life cycle assessment of GHG emissions and primary energy balances
