PS 20-27 - Estimating the Carbon Sequestration Potential of Great Lakes Apple Orchards

Abstract: While fruit growers are on the front lines of dealing with the impacts of climate change, they are also in the unique position of managing large agroecosystems that absorb carbon dioxide through photosynthesis. Unfortunately, research on the carbon sequestration potential of perennial agroecosystems is scarce. Meanwhile, growers, processors, and consumers increasingly want to know the impact their food has on the climate. The objectives of this study are to quantify the net ecosystem production (carbon sequestration) of a free-standing semi-dwarf apple orchard in the Great Lakes region using the Eddy Covariance Method (EC) and to use the DayCent Model to apply the results to orchards in the same bioregion. While mature orchards are estimated to have a lower carbon sequestration potential than younger, more vigorously growing orchards, free-standing semi-dwarf apple orchards, typically maintained for processing apple production, represent 52% of the apple orchards in the Great Lakes Region (MI, NY, PA). The EC Method is a direct measurement that works by positioning a high frequency carbon monitoring instrument next to an anemometer above the tree canopy. As the wind blows across the landscape, the air mass rolls like a ball due to drag created by ground friction causing eddies that bring air both up from the orchard and down from the atmosphere to the ground. Through high frequency carbon dioxide measurements with corresponding vertical wind speed measurements, the carbon dioxide exchange between the orchard and the greater atmosphere is measured. Preliminary results show that from June 29, 2022, to November 25, 2022, there was a net ecosystem production (carbon sequestration) of 99 g C m2. This system will continue to collect data through 2024, providing us with 2 seasons of data. Our hope is that this quantification of carbon in apple orchards will allow growers to “put a number” on the value of their operation as a carbon sink as they meet the public’s demand for carbon neutral commodities and production systems.