碩士 / 國立中興大學 / 生命科學系所 / 94 / The chlorophyll fluorescence of one C3 evergreen conifer (Pinus taiwanensis Hayata) and two C4 perennial grasses (Miscanthus transmorrisonensis Hayata and M. floridulus (Labill.) Warb. ex K. Schum. & Lauterb.) were investigated at predawn and different photosynthetic photon flux density (PPFD) in Tatachia (2,600 m a.s.l.) and Hui-Sun Forest Station (800 m a.s.l.) from September 2003 to February 2006. In winter, they both increase the thermal dissipation in the light (DL) to avoid excess absorbed light energy being transferred into the reaction center (RC) of photosystem II (PSII). In addition, the excess energy (E) sustaining in low range (0.1 ~ 0.2) in any season and PPFD reveals that the reducing of maximum PSII photochemical efficiency (Fv/Fm) ascribes to photoprotection by down-regulation of the PSII efficiency, rather than photoinhibition. C3 plants could dissipate part of excess energy by photorespiration, which is absent in C4 plants. Compared to P. taiwanensis, it is necessary for M. transmorrisonensis and M. floridulus to maintain high proportion of non-photochemical dissipation (DL+L; L, energy lost in the dark) to expel excess absorbed light energy. Consequently, these two plants have lower propotion of photochemical electron transport (P) and higher propotion of DL+L than P. taiwanensis. The variation of Fv/Fm, P, and DL+L of P. taiwanensis is significantly related to temperature and PPFD, and this could be utilized to estimate the energy allocation. Based on PRI (photochemical reflectance index), temperature, and PPFD, multiple regression equation could also help estimate P of P. taiwanensis. At the same P, however, the light-use efficiency (LUE) of P. taiwanensis in Tatachia is significantly higher than in Hui-Sun Forest Station. Due to lower temperature at high elevation, photorespiration consumes less energy in Tatachia. As for the net photosynthesis rate (Pn), it could be estimated through the multiple equations of PRI, PRIpd (PRI at predawn), and temperature or PPFD. Applying leaf spectral reflectance accompanied by chlorophyll fluorescence, temperature and PPFD, the equations of this research could easily and accurately estimate the photosynthesis capacity of P. taiwanensis in different seasons and PPFD.
| Identifer | oai:union.ndltd.org:TW/094NCHU5105028 |
| Date | January 2006 |
| Creators | Kuan-Ming Lai, 賴冠名 |
| Contributors | Jen-Hsien Weng, 翁仁憲 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 75 |
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