Tree Regeneration in a Lowland Rainforest of Nanjenshan, Southern Taiwan: Effects of Gap and Understory Bamboo
| Autor: | Kai-Mei Chen, 陳凱眉 |
|---|---|
| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 99 Gaps are openings in forest canopy which are caused by broken or fallen dead trees. Space and resources release by the formation of forest gaps can provide opportunities for understory growth and establishment. Especially, the growth of high light-demanding species relies on the sunlight under these canopy openings. Furthermore, gaps with different sites and ages may create heterogeneous habitats, and increase species diversity. Lowland rainforests in Nanjenshan are characterized by frequent wind disturbances and broken openings in the forest canopy. This study examined species composition and forest structure under forest gaps and compared with those of adjacent forests with intact canopies. In addition, the effect of the climbing bamboo (Schizostachyum diffusum) cover on regeneration of forest was assessed. The analyses were based on data from three tree-by-tree censuses in 1993, 2000 and 2008. The coverage of the climbing bamboo and forest gaps were measured in 2008. The results showed that there was a notable change in canopy structure from closed in 1993 to more open condition in 2008. The average size of a gap was less than 100 m2. The biggest gap size was found to be over 1000 m2 in 2008. The coverage of climbing bamboo and the proportion of shade-intolerant species in the gaps were both high. The recruitment and mortality rates of individuals in the gaps were also high, and the size of dead trees was large. Besides, the survival of shade-tolerant species was negatively correlated with the coverage of climbing bamboo. The persistence of canopy gaps during the past 15 years may be caused by large tree-fall and a high coverage of climbing bamboo in Nanjenshan forest. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|