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題 名 | 三種臺灣特有種樹苗在不同光環境下的淨光合作用季節變化=Seasonal Variations in Net Photosynthesis of 3 Taiwan Endemic Tree Species Grown under Various Light Environments |
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作 者 | 郭耀綸; 楊月玲; 鄭鈞謄; 傅瑩娟; | 書刊名 | 臺灣林業科學 |
卷 期 | 18:2 2003.06[民92.06] |
頁 次 | 頁107-116 |
分類號 | 436.195 |
關鍵詞 | 臺灣假黃楊; 小芽新木薑子; 臺灣梭羅木; 孔隙; 光合作用適溫範圍; 光抑制; 氣孔傳導率; Liodendron formosanum; Neolitsea parvigemma; Reevesia formosana; Gap; Range of optimum temperature for photosynthesis; Photoinhibition; Stomatal conductance; |
語 文 | 中文(Chinese) |
中文摘要 | 本研究將3種台灣特有樹種台灣假黃楊、小芽新木薑子及台灣梭羅木的苗木培育在相對光量65、35、10%的蔭棚,以及森林孔隙與林下共5種光環境,分四季測定其淨光合作用及相關生理活動的變化,藉以了解其生理活動對環境因子的反應。各種樹苗隨生長環境光量的提高而有較高的淨光合作用率,但在高溫的季節,培育在35與65%光環境苗木的淨光合作用率常無顯著差異。光合作用生產力以9月最高,12月寒流期間明顯降低,然只有台灣假黃楊的淨光合作用率在不同季節均呈顯著差異。培育在孔隙的苗木當有直射光照時,其淨光合作用率為只有散射光照時的3倍,可達6-9 痠ol CO2 m-2s-1,然而孔隙苗在只有散射弱光時的光合作用光量子產量極高。在氣溫較高的6、9月,台灣假黃楊和台灣梭羅木的孔隙苗照到直射強光時會出現光合作用光抑制現象,而小芽新木薑子則否,因後者有顯著較高的氣孔傳導率及顯著較低的葉溫。台灣假黃楊、小芽新木薑子及台灣梭羅木孔隙苗光合作用最適溫度範圍分別為23-31℃、23-35℃及18-29℃,顯示小芽新木薑子較耐高溫,台灣梭羅木較耐低溫。 |
英文摘要 | Seedlings of 3 endemic tree species of Taiwan, Liodendron formosanum, Neolitsea parvigemma, and Reevesia formosana, were cultivated under 5 different light environments. They were placed in a forest understory, in a forest gap, and in 3 artificial shade houses with 10, 35, and 65% of full sun, respectively. Seasonal changes of the net photosynthetic rate and related physiological variables of these seedlings were measured in order to understand their physiological responses to environmental factors. Results showed that as the available light resources increased, the photosynthetic rates increased accordingly. However, net photosynthetic rates, measured in hot seasons, between seedlings grown under the 35 and 65% light environments showed almost no significant differences. Photosynthetic productivity peaked in September and dropped significantly during a cold period in December. Among these 3 species, only L. formosanum showed significant seasonal variations in net photosynthetic rates. The net photosynthetic rates of seedlings grown in the forest gap were 3-fold higher (6-9 痠ol CO2 m-2s-1) when receiving direct bright light compared to rates when receiving only diffuse, dim light. However, their photosynthetic quantum yields were very high when receiving diffuse, dim light. Photoinhibition occurred in gap seedlings of both L. formosanum and R. formosana when receiving direct bright light in June and September, whereas, gap seedlings of N. parvigemma showed no sign of photoinhibition, which could be attributed to their high stomatal conductance and consequent maintenance of relatively low leaf temperatures. The range of optimum temperatures for photosynthesis in gap seedlings of L. formosanum, N. parvigemma, and R. formosana were 23-31℃, 23-35℃, and 18-29℃, respectively. These results indicated that N. parvigemma can tolerant higher temperatures, while R. formosana can tolerant lower temperatures. |
本系統中英文摘要資訊取自各篇刊載內容。