經由碳平衡及二氧化碳通量之量測推估蝴蝶蘭園之最佳溫度及光照條件

Abstract

本研究目的為利用渦流共變異數技術量測二氧化碳通量之日碳平衡，以評估蝴蝶蘭園最佳溫度及光照條件，其結果將有助於在溫室栽培之蘭花管理。結果顯示，日/夜溫為25/25℃可得葉片之最高日碳平衡，而由整個園區尺度之碳通量資料，最佳蘭園溫度範圍為24-27℃之間。由整年通量量測資料，日均溫與日碳平衡之相關係數為0.65，然而，夜溫與二氧化碳固定較日溫與呼吸作用更顯著。景天科作物之光反應及暗反應是分開進行，最佳光照利用碳平衡及葉綠素螢光參數量測所得結果為300-500 μmol m-2 s-1。除此之外，每日之日夜1 個循環較2 個及3 個循環有更多碳固定量。潛熱與溫度及光度相關性皆不明顯，主要原因為水牆風扇干擾溫室內水汽狀態所致。 The main objectives of this study were to evaluate the conditions of best temperature and light intensity of greenhouse/structure growing Phalaenopsis by the measurement of daily carbon balance with CO2 flux using eddy covariance technique for the purpose of improving orchid management in greenhouse cultivation. The results indicated that the maximum carbon balance can be reached at the day/night temperature of 25/25℃ on leaf basis, and in range of 24-27℃ on the base of greenhouse as a whole. The correlation coefficient between daily mean temperature and carbon balance was 0.65, calculated by annual eddy flux data. The relationship between night temperature and CO2 fixation was stronger than day temperature and respiration. The light and dark reactions of carbon fixation for crassulacean acid metabolism (CAM) plant were separated. The suitable light intensity range for Phalaenopsis leaves was 300-500 μmol m-2 s-1 from the measurements of daily carbon balance and fluorescence parameters. In addition, higher daily carbon balance occurred in 1 day/night cycle per day (148.3 μmol CO2 m-2 day-1) compared with 2 cycles (127.1 μmol CO2 m-2 day-1) and 3 cycles (92.4 μmol CO2 m-2 day-1). Latent heat was not significantly correlated with temperature and light intensity because the pad-fan interfere the vaporing of water in greenhouse.