ESTIMATING THE CARBON FOOTPRINT OF MICHIGAN APPLE AND CHERRY TREES - LIFETIME DRY MATTER ACCUMULATION
Currently, the apple and cherry industries are considering if these commodities might qualify for trading carbon credits on carbon exchanges. We are developing carbon sequestration estimates for Michigan orchards. We have estimated tree carbon assimilation and sequestration using the apple carbon balance model (Lakso et al., 2001). Using these data we have also estimated the carbon footprint for both apple and cherry. Herein we describe lifetime dry matter accumulation for both apple and cherry and relate it to trunk cross-sectional area (TCSA). Dry matter was measured in the fall of 2009 and 2010 for cherry and apple at three different sites. Total biomass in the perennial structure of trees was measured from trees excavated and trunk circumference was measured for each tree, 45 cm aboveground. The study was conducted on 27 apple trees (cultivars: Gala, Red Delicious, Red Chief, and Mutsu on different rootstocks) and 20 Montmorency cherry trees (10 and 30 years old). Fresh weight of recoverable roots, trunks, and branches was recorded in the field after excavation. Subsamples of roots and aboveground wood from different ages of the canopy were collected, weighted, and dried to constant weight at 60°C. The calculated percentage of dry weight (approximately 62% for both species) was used to estimate dry biomass weight of excavated trees. Trees total dry weight (kg) was found to be linearly correlated with TCSA (cm2) in apple (DW=0.30*TCSA; R2=0.97) and cherry (DW=0.40*TCSA; R2=0.95). Similar regression equations can be applied selectively to aboveground trees dry biomass (DW=0.22*TCSA; R2=0.95 for apple and DW=0.25*TCSA; R2=0.96 for cherry) and root dry biomass (DW=0.08*TCSA; R2=0.93 for apple and DW=0.15*TCSA; R2=0.93 for cherry). On the sampled trunk sections, we measured cross sectional area growth according to growth rings and used it to estimate annual dry biomass sequestered by single trees. Mean annual dry biomass sequestered was 4.5 kg/tree in 30 years old cherry trees and varied from 1.1 to 2.7 kg/tree in apple trees, where the variability may be explained by the different age, rootstocks, and cultivars of the trees employed. The carbon footprint estimated from the photosynthesis model and from dry matter estimate from TCSA will be compared for both apple and cherry.
Tozzini, L., Lakso, A.N. and Flore, J.A. (2015). ESTIMATING THE CARBON FOOTPRINT OF MICHIGAN APPLE AND CHERRY TREES - LIFETIME DRY MATTER ACCUMULATION. Acta Hortic. 1068, 85-90
whole tree biomass, Malus domestica, Prunus cerasus