HMF Permanent Plot System

Methodology >> Plot Surveys

  1. The tally on the plot will include all tree species of 0.5" DBH and greater which will be classified by 1 inch diameter classes. (2"=1.5-2.5" etc.)

  2. Small sapling, reproduction, and vegetation will be tallied on 10 milacres on each plot. All reproduction will be classified in the following height and diameter classes 0.0-0.4', .5, to 9', 1.0' to 1.9', 2.0' to 2.9', 3.0', to 3.9', 4.1'h to .5" DBH and .6" to 1.5" DBH. (In the 1930s there was no 0.0-0.4' height class).

  3. Defective trees will be tallied and classified as to estimated percent of merchantability (1930s survey only). Trees which appeared to have died within the past ten years will be tallied as such and all dead trees will be distinctively marked (probably notched with a hatchet). Trees forking below the breast height will be tallied as two trees. Trees or saplings necessarily cut (minimum number) along the boundary lines will not be tallied. [ starting in 1971-1972 all standing dead trees tallied separately.] On the regular cruise lines defect tally will be confined to the trees, i.e., those 2.1 and over 10" DBH. The defect tally will be kept on a separate sheet and taken on 10% of the plots (mechanically distributed). For each defective tree the tally will show species, DBH, and percentage of cull in each 16 ft. log length. Pathological and physical cull will be shown in separate columns. [not done after 1930s]

  4. General notes which will be confined largely to the plots will in a general way describe the reproduction, the herbaceous layer, site, slope, soil, condition of the stand (general appearance and defects), and any further information that would tend to present a clear picture of the plot.

  5. Heights are obtained on sufficient softwood trees and hardwoods below merchantable size to form satisfactory curves of height on diameter for the various types, sites, and age classes. When done with the regular plot work, the trees measured are distinctively tagged or painted to make possible remeasurement in the future.