1. Prediction: M ~ D 8/3 (Niklas & Spatz, 2004) Tree-level: Exponent [95% Confidence] Intercept R 2 All -2.49 [2.32, 2.68] -0.93 0.974 Apple -2.48 [2.31, 2.67] -0.90 0.980 Cherry - 4.37 [1.47, 12.9] -5.16 0.489 Branch-level: Exponent [95% Confidence] Intercept R 2 All -2.48 [2.43, 2.53] -1.05 0.905 Apple -2.57 [2.48, 2.67] -1.21 0.869 Cherry -2.46 [2.39, 2.53] -1.01 0.907 Rootstocks: Exponent [95% Confidence] Intercept R 2 Bud.9 -2.56 [2.11, 3.12] -1.25 0.647 CG.3041-2.63 [2.42, 2.87] -1.19 0.907 CG.6210 -2.76 [2.52, 3.02] -1.47 0.788 M.26 -2.76 [2.47, 3.08] -1.54 0.929 JM.8 -2.51 [2.34, 2.69] -1.13 0.916 PiAu.5683 -2.47 [2.27, 2.69] -1.06 0.851 Evaluating scaling relationships of branching structure and biomass partitioning in managed orchard fruit species Zachary T. Brym, Dept. of Biology and Ecology Center, Utah State University Research Questions Are ‘universal’ scaling relationships between diameter, length and mass, described by the Metabolic Theory of Ecology, conserved in managed orchard fruit species? Where deviations occur, are they indicative of orchard management practices (i.e., pruning)? Experimental Systems Kaysville Experimental Orchard, USU Ag. Experiment St. Medium-density Apple (Malus x sylvestris var. domestica) - 3.5 x 5.5 m spacing, Vertical Axe training system - NC-140 2003 Golden Delicious rootstock trial - designed to evaluate dwarfing, yield, and disease resistance Low-density Tart Cherry (Prunus cerasus, mahaleb) - 3.65 x 6.1 m spacing, general open vase training - management abandoned for more than 5 yrs. - secondary branches closer to wild-type habit Key Findings Mass ~ Diameter is strongly conserved. The estimated scaling exponent is just shy of 8/3, the theoretical self-loading limit before buckling. Length ~ Diameter is moderately conserved. Confidence intervals include the 2/3 prediction, but also 3/4. Vigorous shoots suggests pruning signals. Length ~ Mass is moderately conserved. Confidence intervals include the 1/4 prediction, but also 2/3. Vigorous wood may have lower density. The Diameter Ratio is moderately consistent. The ratio is higher than predicted, indicative of area decreasing branching. Slow taper in large supporting branches results from pruning of smaller end shoots. Future Directions Explore data for spatially explicit branching architecture and develop a model for effects of pruning on canopy shape and structure. Explore predictive power of non-destructive tree morphology (e.g., canopy volume and light interception) on yield in commercial tart cherry orchards of Utah Co. Develop agroecological philosophy for forest-like orchard agroecosystems. A Weecology Production Acknowledgements Project funding provided by the Utah State University Graduate Student Senate Research and Project Grant and the Ecology Center Ph.D. Assistantship and Research Support Award. Field support from the staff and researchers at the Kaysville Experimental Orchard and USU undergraduates Josh Anderson and Josh Shugart greatly influenced the project’s sample size. Conference travel provided by the USU Office of Graduate Studies, Ecology Center and Dept. of Biology, GRC, and ASHS. Mass vs. Diameter Prediction: M ~ (D /2 ) 2/3 (Price, Enquist & Savage, 2007) Tree-level: Exponent [95% Confidence] Intercept R 2 All -0.74 [0.63, 0.88] -0.72 0.849 Apple -0.80 [0.68, 0.95] -0.81 0.892 Cherry - 1.29 [0.35, 4.77] -1.84 0.125 Branch-level: Exponent [95% Confidence] Intercept R 2 All -0.87 [0.82, 0.91] 1.09 0.442 Apple -1.10 [1.02, 1.19] 0.70 0.420 Cherry -0.83 [0.78, 0.89] 1.19 0.491 Rootstocks: Exponent [95% Confidence] Intercept R 2 Bud.9 -1.50 [1.11, 2.02] 0.33 0.154 CG.3041-1.14 [0.96, 1.35] 0.75 0.614 CG.6210 -1.39 [1.21, 1.60] 0.43 0.482 M.26 -1.13 [0.83, 1.54] 0.70 0.418 JM.8 -1.13 [0.94, 1.36] 0.54 0.406 PiAu.5683 -1.07 [0.90, 1.28] 0.66 0.347 Length vs. Diameter Prediction: L ~ M 1/4 (Niklas & Enquist, 2001) Tree-level: Exponent [95% Confidence] Intercept R 2 All -0.30 [0.25, 0.35] -0.67 0.849 Apple -0.32 [0.27, 0.39] -0.76 0.876 Cherry - 0.29 [0.12, 0.74] -0.71 0.673 Branch-level: Exponent [95% Confidence] Intercept R 2 All -0.35 [0.33, 0.36] 1.19 0.632 Apple -0.43 [0.40, 0.46] 0.89 0.658 Cherry -0.33 [0.32, 0.35] 1.28 0.638 Rootstocks: Exponent [95% Confidence] Intercept R 2 Bud.9 -0.58 [0.49, 0.70] 0.61 0.688 CG.3041-0.43 [0.39, 0.48] 0.93 0.840 CG.6210 -0.50 [0.46, 0.55] 0.75 0.766 M.26 -0.41 [0.31, 0.55] 0.99 0.500 JM.8 -0.45 [0.39, 0.53] 0.71 0.587 PiAu.5683 -0.43 [0.38, 0.50] 0.79 0.580 Length vs. Mass Diameter Ratio Prediction: D k+1 /D k ~ 0.5 Branch-level Exponent [95% Confidence] Intercept R 2 All-0.68 [0.65, 0.71] -8.48 0.569 Apple-0.67 [0.61, 0.72] -11.4 0.418 Cherry-0.75 [0.71, 0.79] -8.78 0.693 Legend Prediction - Exponent - 95% CI - Cherry -Apple - Bud.9 -CG.3041- CG.6210 -M.26 - JM.8 -PiAu.5683 - R 2 = 0.569