earticle

영어

With the advancement of laser scanning technologies, many studies have attempted to represent various spatial structures across urban forests. Especially, the multitemporal LiDAR approach has been used for deriving the changes in urban forest structures. The overarching goal of this study is to investigate three-dimensional changes in urban canopy structures using multi-temporal LiDAR datasets with a particular focus on forest gaps and open canopies formed by natural and artificial disturbances. Specifically, we compared the structural changes in open canopy areas by the different types of disturbed areas in urban forests. The research site is Mt. Bongseo (altitude: 158 m, area: 124 ha), located in Cheonan city, Chungcheongnam-Do, Republic of Korea. It is a mixed forest where the dominant species are Quercus acutissima (44.8%), Pinus rigida (29.7%), and Larix leptolepis (7.4%), and the average age class is class 3.8 (30 to 40-year-old forest). As the site is located adjacent to the downtown area, sports facilities and, outdoor education center were built in the forest nearby the trail. The airborne LiDAR datasets were acquired on October 9, 2012, May 16, 2013, June 16, 2014, and October 30, 2015, using IGI LiteMapper 6800. The results presented small opening areas distributed more frequent (scaling exponent = 1.28) in the naturally formed canopy openings (forest gaps), while larger opening areas distributed more frequent (scaling exponent = 1.22) in the artificial disturbances during the study periods. The values of changes in both plant area index (PAI) and canopy complexity were the greatest in the forest gaps, which could be interpreted that forest gaps (0.12 m2/m2 and 0.93 m2/m2, respectively) served to diversify the canopy structures. In contrast, artificially disturbed areas showed very low dynamics (0.01 m2/m2 and 0.15 m2/m2 changes in PAI and canopy complexity, respectively), and their areas had been widened during the study periods.