RT Journal Article SR Electronic T1 Determination of Crew Size Efficiency Relative to Urban Tree Inventories JF Arboriculture & Urban Forestry (AUF) FD International Society of Arboriculture SP 223 OP 229 DO 10.48044/jauf.2015.021 VO 41 IS 4 A1 Arthur H. Chappelka A1 Edward F. Loewenstein A1 Greg L. Somers A1 Gary J. Keever A1 Nicholas A. Martin YR 2015 UL http://auf.isa-arbor.com/content/41/4/223.abstract AB Trees on the campus of Auburn University (Auburn, Alabama, U.S.) were used to test the efficiency of different crew sizes in conducting a 100% tree inventory. Seventy trees were randomly sampled at-large from a previously conducted 100% inventory (7,345 trees) on the Auburn University campus. Different crews consisting of one, two, or three individuals collected and recorded data using a GPS unit that timestamped the initiation and completion of data collection for each tree. The average time spent per tree was then calculated. Crews visited separate trees each time so there would be no overlap or bias. Each tree sampled was visited by all three crew sizes at different times. The relationship of sampling time per tree with increasing tree dbh was determined using regression analysis and subsequently likelihood ratio F tests. There was no statistical difference in the interval required to inventory a tree as dbh approached 0 (intercept, fixed time) for a two- and three-person crew, but the set-up (fixed) time for a one-person crew was significantly greater (approx. 2×) irrespective of dbh. The time interval it takes to inventory each tree increased with increasing dbh; however, the rate of change was significantly less for a three-person crew compared with the other crew sizes. Based on these results, the number and relative sizes (dbh) of trees to be inventoried must be considered when determining optimal crew size.