Response of Two Oak Species to Reduction Pruning Cuts

Article Figures & Data

Table 1.

A listing of parameters used in analysis.

Discoloration	Growth	Dimensioning	Angle
Depth discoloration	Relative growth rate	Initial branch diameter	Actual cut angle
Area discoloration	Aggregated sprout diameter	Cut diameter	Branch bark ridge angle
Discoloration area percentage		Aspect ratio	Target angle
Normalized discoloration area		Final branch diameter	Dieback angle
		Branch departure angle	Difference: dieback angle from cut angle
			Difference: cut angle from target angle

Table 2.

Significant growth rate relationships in live oak and shumard oak in response to reduction pruning.

Equation 2^{^y}	RGR (live oak) = 0.807 − 0.121 initial branch diameter r² = 0.559, regression model P < 0.001
Equation 3^{^z}	RGR (shumard oak) = 1.93 − 0.361 initial branch diameter r² = 0.462, regression model P < 0.001
Equation 4^{^z}	RGR (live oak) = 0.674 − 0.583 aspect ratio r² = 0.338, regression model P < 0.001
Equation 5^{^z}	RGR (shumard oak) = 1.96 − 1.90 aspect ratio r² = 0.42, regression model P < 0.001

Table 3.

Significant discoloration relationships in live oak and shumard oak in response to reduction pruning.

Equation 6^{^z}	Depth of discoloration (live oak) = 73.8 − 1.02 branch departure angle r² = 0.156, regression model P = 0.017
Equation 7	Area of discoloration (live oak) = 41.6 + 0.683 initial cut diameter (cm) r² = 0.123, regression model P = 0.033
Equation 8^{^z}	Area of discoloration (shumard oak) = 35.0 + 3.35 initial cut diameter (cm) r² = 0.615, regression model P < 0.001
Equation 9^{^z}	Area of discoloration (live oak) = 46.9 − 0.124 aggregated sprout base diameter r² = 0.17, regression model P = 0.011

Table 4.

Significant dieback angle relationships.

Equation 10^{^y}	Dieback angle (live oak) = 13.3 + 0.735 angle of cut r² = 0.611, regression model P < 0.001
Equation 11^{^z}	Dieback angle (shumard oak) = 18 + 0.667 angle of cut r² = 0.276, regression model P < 0.001 (one outlying datum removed)
Equation 12^{^z}	Dieback angle (shumard oak) = 27 + 0.798 angle of cut − 2.24 initial cut diameter r² = 0.356, regression model P < 0.001