Radius of wood core 18 16 = 2 – – length Number of rings 5 (innermost inch) Product (of #5 and #6 2 x 5 = 10 above) Number of rings on 200 + 10 = 210 tree age core + 10 (7) Age Measurements for Trees < 3 inches DBH For trees less than 3.0 inches DBH, total tree age may be determined by counting branch whorls that represent annual height increments, by severing the tree at the root collar and counting annual rings, or by taking an increment boring at the root collar. Counting Branch Whorls Counting branch whorls to determine tree age should only be done on western white pine or other species where the distinction between annual branch whorls and false branch whorls can be clearly recognized. False branch whorls are recognized as whorls that have shorter branches and never have budscale scars at the node. The presence of budscale scars guarantees that the branch whorl represents an annual growth increment, but as a tree ages, budscale scars become masked by bark development. Western red cedar does not have budscale scars and false whorls are common, so counting branch whorls is never appropriate for cedar. Figure : Counting branch whorls Cutting Tree at Root Collar to Count Annual Rings Sample trees can be severed at the root collar in order to count annual rings. The root collar is the transition zone between the stem and the root and is recognized by the presence of a slight swelling. Figure : Cut tree at root collar Increment Boring at Root Collar
Radius of wood – core length 18 – 16 = 2 Number of rings (innermost inch) 5 Product (of #5 and #6 above) 2 x 5 = 10 Number of rings on core + 10 (7) 200 + 10 = 210 tree age Age Measurements for Trees < 3 inches DBH For trees less than 3.0 inches DBH, total tree age may be determined by counting branch whorls that represent annual height increments, by severing the tree at the root collar and counting annual rings, or by taking an increment boring at the root collar. Counting Branch Whorls Counting branch whorls to determine tree age should only be done on western white pine or other species where the distinction between annual branch whorls and false branch whorls can be clearly recognized. False branch whorls are recognized as whorls that have shorter branches and never have budscale scars at the node. The presence of budscale scars guarantees that the branch whorl represents an annual growth increment, but as a tree ages, budscale scars become masked by bark development. Western red cedar does not have budscale scars and false whorls are common, so counting branch whorls is never appropriate for cedar. Figure : Counting branch whorls Cutting Tree at Root Collar to Count Annual Rings Sample trees can be severed at the root collar in order to count annual rings. The root collar is the transition zone between the stem and the root and is recognized by the presence of a slight swelling. Figure : Cut tree at root collar Increment Boring at Root Collar
userguide_fsveg_ch4_collect-record-data.docx