| Summary: | 碩士 === 國立臺灣大學 === 森林環境暨資源學研究所 === 94 === This study was proceeded in the nursery at Chitou from June, 2004 to November, 2005. The objectives were to establish the basic information about the photosynthesis and the chlorophyll fluorescence of four native broad-leaf tree species in Taiwan, which were Nanban tanoak(Pasania ternaticupula (Hayata) Schott.), Ring-cupped oak (Cyclobalanopsis glauca (Thunb. ex Murray)), Arisan oak (Cyclobalanopsis stenophylloides Hayata) and Camphor tree (Cinnamomum camphora (L.) Presl), under different light intensities and nitrogen levels. Treatments of light intensities were measured with relative light intensities which were 10%, 50% and 100%, respectively. Different nitrogen levels were achieved by applying nitrogen fertilizer in the amount of 200 kg/ha/yr(N2), 300 kg/ha/yr(N3), 400 kg/ha/yr(N4), 500 kg/ha/yr(N5) and 600 kg/ha/yr(N6), respectively. We measured the heights and diameters of seedlings monthly throughout the experiment at period. We also measured the photosynthesis and the chlorophyll fluorescence of the seedlings from September to November, 2005. Results showed that all of the four species had the greatest height growth in 50% light intensity and 100% light intensity inhibited the height increasing growth. By contracted diameters increased with light intensity. Higher N levels increased both height and diameters. Dark respiration and light compensation point also increased with light intensities. While the quantum use efficiency of Ring-cupped oak did not differ significantly among treatments, that of the other three species was the high significantly in 50% light intensity than in the other two light intensities(10% and 100%). The maximal assimilation rate of Nanban tanoak and Arisan oak was measured in the full light treatment but that of Camphor tree and Ring-cupped oak was measured in 50% light intensities. Fv/Fm in three of four species, except Nanban Tanoak, decreased in full light intensity. ΦPSII of Ring-cupped oak and camphor tree had the minimal value in full light treatment and maximal value in 50% light intensities. ΦPSII of Arisan oak was little affected by light intensity. Nanban tanoak had better performance in full light and 50% light intensities. The qP of three out of four species, except Ring-cupped oak, increased with light intensities. The qP of Ring-cupped oak had the maximal value in 50% light intensities and the minimal value in the full light. The NPQ of three out of four, except Arisan oak, increased with light intensities. The Nitrogen levels had no significant effects on the photosynthesis and chlorophyll fluorescence of the four species. Ring-cupped oak an Camphor tree showed inhibition of PSII in high light intensities. Nitrogen levels did not influence the physiology of the four species but it would help for height and diameter growth.
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