. Journal of forestry . he right-handdiagram shows a similar presentation of data obtained at BrandrethLake and two quite distinct breaks occur in the curve, one of whichconforms in diameter class to that found in the other study. Theseare interpreted to mean an interruption in the condition of growth,especially light relation, due possibly to severe windfall. In figure 5 is shown graphically the amount of spiral in terms ofper cent of the total number of trees in each diameter-class group. Onthe vertical line D, which represents a spiral of i inch in 20 inches, or5 per cent curve, No. 3 shows
. Journal of forestry . he right-handdiagram shows a similar presentation of data obtained at BrandrethLake and two quite distinct breaks occur in the curve, one of whichconforms in diameter class to that found in the other study. Theseare interpreted to mean an interruption in the condition of growth,especially light relation, due possibly to severe windfall. In figure 5 is shown graphically the amount of spiral in terms ofper cent of the total number of trees in each diameter-class group. Onthe vertical line D, which represents a spiral of i inch in 20 inches, or5 per cent curve, No. 3 shows 50^ per cent of all the trees over 14inches in diameter meeting this specification. Curve No. 4 representsall trees over 14 inches measured at Brandreth and shows 525/^ per centstraigliter than i inch in 20 inches. Similarly curve No. 2, representingtrees 9 inches to 13 inches, inclusive, shows them generally straighterthan the larger ones, while curve No. i shows trees up to 8 inches lessspiraled than any other 0/. ZZ 4Z 6% 8Z foZ ^^Z Fig. 5.—Proportionate amount of spiral in small, medium, and large trees Curve I, trees i inch to 8 inches, inclusive. Curve 2, trees 9 inches to 13 inches, 3, trees 14 inches and larger. Vertical Co-ordinate A, straight trees. Vertical Co-ordi-nate B, trees straighter than i inch in 40 inches. Vertical Co-ordinate C, trees straighterthan I inch in 30 inches. Vertical Co-ordinate D, trees straighter than i inch in 20 Co-ordinate E, trees straighter than i inch in 15 inches. Curve 4, showing propor-tionate amount of spiral in trees 14 inches and larger. Taken for comparison from 598 treeson the northeast side of Brandreth Lake, on the Brandreth estate. KNOT ZONES AND SPIRAL IN ADIRONDACK RED SPRUCE 787 No. of Straight 2%% 3 1/3% 5% 62/3% trees (1/40) (1/30) (1/20) (1/15) Per cent 443 39-6 392 49 5 340 48 8 286 27-3 370 48 2 63-7 244
Size: 1267px × 1971px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectforestsandforestry
