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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. 2x) 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. [ABSTRACT FROM AUTHOR]

The article describes the case of predicting ecosystem services at Auburn University through the assessment of the standard plot sampling protocol for i-Tree Eco. Researchers conducted a tree inventory of the managed areas of campus, providing a complete data set for the evaluation. They also analyzed ecosystem services such as air pollution removal, carbon storage, and carbon sequestration. Total tree population was used to allow for comparison with the i-Tree Eco protocol.

The article presents a study that examined the development of predictive open-grown crown width equations for three oak species in urban forests in the southern U.S., namely, the overcup oak, the Nutall oak, and willow oak, by using diameter at breast height and crown width data. The authors claim that the equations can aid urban landscape and utility planners by providing a means to predict crown dimensions at varying trunk diameters. Materials and methods used in the study are discussed.

The article discusses a study on the applicability of i-Tree Eco using 100% inventory of the trees within the campus of Auburn University in Alabama. Tree data collected include diameter at breast height (DBM), tree height, crown width, percent dieback and tree conditioning dating. The study concludes the i-Tree Eco procedures were found to be an effective and efficient tool that provided valuable information on the urban forest structure and function of the surveyed area.

Loblolly pine (Pinus taeda L.) seedlings from two families differing in ozone sensitivity, were exposed to ozone and acidic precipitation in modified open-top chambers, beginning in May of 1988. Visible injury (bleached needle tips) occurred after a late-season frost in April, 1989 on newly emerging (length ⩽ 5 cm) needles. After one week, needle tips turned brown and necrotic. Incidence of injury was recorded in April. May and June, 1989. Injury only occurred on trees exposed to ozone at above-ambient concentrations (1.7 and 2.5 × ambient), and was significantly greater in the ozone-sensitive family (GAKR 15-91) suggesting that this response is under some genetic control. Incidence of injury decreased with time and was more noticeable in the ozone-tolerant family (GAKR 15-23). There was no effect of acid rain, or interaction between ozone and acid rain, revealed by visible injury. In addition, experiments were conducted to determine if ozone and/or freezing temperatures enhanced electrolyte leakage. There were no differences observed in diffusate conductivity among treatments. These findings suggest that the observed injury was due to photo-oxidation induced by an ozone-low temperature interaction, and represent the first report of this type of injury in loblolly pine. [ABSTRACT FROM AUTHOR]