Age structure of Podocarpus macrophylla (Thunb.) Sweet in Nanjenshan Subtropical Rain Forest

• Main Authors: Sheng-Chieh Wu, 吳聖傑
• Other Authors: Chang-Fu Hsieh
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/45662472231028712715

碩士 === 國立臺灣大學 === 植物學研究所 === 87 === The major subject in this study is to investigate age structure of population of Podocarpus macrophylla (Thunb.) Sweet in a 3-ha permanent plot in Nanjenshan subtropical rain forest of southern Taiwan. Sex observed that stems were more than 3cm diameter at breast height (DBH) and annual growth ring sampled 44 trees. Consider the dynamics check data in 1997, to confer population structure at different habitats. The smallest DBH of bloom individuals was 4.1cm, but there were some larger stems haven''t flowing in our observed period of two years. It''s seems that there were weak relationship between physiological maturity and DBH class, but related to microhabitat. Sex ratio were exhibited female-biased in whole plot and windward I habitat except windward II habitat. This result were conformed to Kaplan (1972) theory that high density population were trended to female-biased, and possible concern about wind-pollination dioecious species show female-biased that location at frequency disturbance area that description by Gibson & Menges (1994).It''s revealed P. macrophyllus were colonial potential species in this plot. Trees with different growth rates and size-age relationships occurred in the same stand. Diameter structure curves were reverse J shape and age structure exhibited slight bell shape. Data on both age and spatial dispersion added critical information on stand dynamics not available from size alone.