Appropriateness of Handheld Garmin GpsMap 76csx in Urban Tree Inventory

摘要

This study was intended to ascertain the suitability of Garmin GpsMap 76csx for use in urban tree inventory. The inventory involved the use of a GPS receiver, Garmin GPSmap 76CSx, and a diameter tape. Data were collected from 85 honeylocust trees and analyzed using ArcMap (average nearest neighbor tool) and a conventional method of estimating age. A map was generated in ArcMap to aid the examination of tree positional accuracy. The results indicate that most honeylocust trees were planted around the administration and Agriscience buildings, the Commons Food Court and near the corner along 19~(th) street. The trees exhibited statistically significant clustering patterns (p <.05, Z =-5.28) and the Estimated Position Error (EPE) ranged from 4 to 7 meters with a mean of 4.6 meters. This show that the device was fairly accurate in locating the trees. The largest honeylocust tree had a girth of 300cm, DBH of 95.5cm and about 75 years old while the smallest measured 29.6 cm in circumference, DBH of 9.4 cm and about 7 years old. GIS/GPS integration in conventional tree data collection methods helps in generating valuable information that boosts the management of the urban forest. Garmin GpsMap 76csx is suitable for trees in an urban environment. The device is more effective with slightly lower EPE values when most trees have shed leaves (autumn) so as to minimize multipath errors resulting from the canopies.