Integrating Photometric Image and LiDAR Data for Monitoring Forest Gap Dynamics in Nanjenshan Area

• Main Authors: Lin,Tse-Hsin, 林哲欣
• Other Authors: Chen,Chaur-Tzuhn
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/48395762275478507936

碩士 === 國立屏東科技大學 === 森林系所 === 102 === Forest gaps are from in the forest canopy when one or a few canopy tree die or is injured in a forest. The small opening or holes would become a kind of succession area filled with other trees in process forest gap regeneration or gap dynamics.The gap dynamics is a natural phenomenon of forest successions which affects the species composition, stand structure and regeneration in forest ecosystems. The purposes of this study are to discuss the forest gap dynamics in Nanjenshan via high resolution images and integrated laser scanning systems. First of all, we mapped the gap distribution in each habitat with multi-temporal aerial photos to understanding the change of gap dynamics in different habitats. Secondly, we modeled the processes of gap dynamics in each habitat and mapped spatial distribution of gaps. We further compared the rate of gap canopy closure with vertical structure in every single habitat. This study analyses three-temporal (2003, 2007, 2009 years) to understanding the change of gap rate, results showed the highest gap rate was 0.92% in 2009 years, secondly was 0.66% in 2003 year, and the lowest gap rate was 2007 years (0.51%). Gap dynamics was a notable change in canopy structure from closed to more open, and 2007~2009 years gap formation rate was higher than 2003~2007 years. This area displays the frequent interference by the Typhoon and the fairly fast conversion rate of forest. According to the classification criteria of topographic to divided into four different habitats (wind-stress, windward, leeward and valley) to explore the gap spatial in difference habitat. Results showed gap size rate of wind-stress and valley was higher than other habitats. Therefore speculate that wind-stress and valley often affected by northeast monsoon. Furthermore, this study combined with aerial photos and three-dimensional airborne laser scanning data to observate the gap vertical structure, and mapped width and depth of gap. There was a positive relationship between width and depth of gap, which means that gaps may range in area from the openings created by the death of a large tree.