不同室內光環境對特定景觀植物光合作用速率及生長表現之差別效應

Abstract

本文研究由市面販售之常見室內景觀植物中依耐陰特性選購12種為試材，首先依照淨二氧化碳交換速率（視同光合作用速率）評估對室內光環境之需求，篩選出較高正值淨二氧化碳交換速率之6種植物。繼而在室內條件下給予此6種植物不同的額外光照處理，以探討利用人工光源提高室內光照強度是否具有促進其光合作用及生長表現之作用，達到降低室內二氧化碳濃度類似淨化室內空氣品質之效果。本試驗設於行政院農業委員會農業試驗所霧峰總所，12種景觀植物在低光照(28.6±1.2μmol m^(-2) s^(-1))、高二氧化碳濃度(504.4±52.1 ppm)的室內環境下，經過5wk後發現以「巴黎美人粗勒草」(＂Aglaonema＂ spp. var. 'PattayaBeauty')、「黃金葛」(＂Epipremnum aureum＂)、「綠孔雀粗勒草」(＂Aglaonema＂ spp. var. 'Greenpeacock')、「極光粗肋草」(＂Aglaonema＂ spp.var. SiamAurora')、「星光燦爛黛粉葉」(＂Dieffenbachia＂ spp. var. 'Sparkles')及「白鶴芋」(＂Spathiphyllum floribundum＂)等6種植物淨二氧化碳交換速率較高，乃篩選出進行後續室內額外光照處理試驗。後續試驗以室內螢光燈管之光照強度(6.1±1.0μmol m^(-2) s^(-1))為對照組(CK)，外加不同波段人工光源，分別為23W白光省電燈泡(ELB-W_(23W)；27.7±1.2μmol m^(-2) s^(-1))、23W黃光省電燈泡(ELB-Y_(23W)；23.7±1.3μmol m^(-2) s^(-1))、10W白光發光二極體(light-emittingdiode; LED)燈泡(LED-W_(10W);27.8±0.7μmol m^(-2) s^(-1))、或10W黃光LED燈泡(LED-Y_(10W);31.3±2.7μmol m^(-2) s^(-1))，合計5種光環境處理。試驗結果顯示，LED-W_(10W)會促進「綠孔雀粗勒草」、「巴黎美人粗勒草」及「黃金葛」之生長速率，ELB-W_(23W)及LED-W_(10W)可加速「星光燦爛黛粉葉」生長，LED-W_(10W)及LED-Y_(10W)對「極光粗肋草」植株生長有促進效果，ELB-W_(23W)及LED-Y_(10W)則可加快「白鶴芋」生長。不同額外光照處理除了可促進上述不同景觀植物生長速率外，隨著光照處理週數延長，淨二氧化碳交換速率呈現明顯增加，例如第5週之淨二氧化碳交換速率較第2週者增加1.5-3倍。綜合試驗結果，可歸納出特定景觀植物對於光強度及光波段的需求與反應有所不同，因此在選購室內景觀植物時，宜同時考量室內光照質量及景觀植物特性來配合其他室內環境條件。另可增加特定波段的人工光源來提高光照強度，以促使特定景觀植物發揮其光合作用效果，藉由消耗較多二氧化碳而達到類似淨化室內空氣品質之目的。 Twelve ornamental plant species suitable for indoor growth conditions were selected to study their ability to tolerate low light levels. The tolerance to indoor light environment for these plants were assessed and compared by the net exchange rate of carbon dioxide (NERC). Six plant species with higher NERC were chosen and then grown indoors providing with additional lighting from various artificial light sources to study whether increase of light intensity would promote their NERC and growth performance so as to reduce indoor carbon dioxide concentration for a better indoor air quality. The experiments were carried out at Taiwan Agricultural Research Institute and the selected uniform potted plants were grown under conditions of low light (28.6±1.2 μmol m^(-2) s^(-1)) and high carbon dioxide levels (504.4±52.1 ppm). After 5 wk of growth, plants of ＂Aglaonema＂ spp. var. 'Pattaya Beauty', ＂Epipremnum aureum＂, ＂Aglaonema＂ spp. var. 'Green peacock', ＂Aglaonema＂ spp. var. 'Siam Aurora', ＂Dieffenbachia＂ spp. var. 'Sparkles', and ＂Spathiphyllum floribundum＂ were found to have a higher NERC than others. These plants were then provided with additional artificial light sources and were compared with plants grown under indoor fluorescence lamps (6.1±1.0 μmol m^(-2) s^(-1)) as control check. The light intensity was increase to 27.7±1.2 μmol m^(-2) s^(-1) with 23 W white light energy-saving light bulb (ELB-W_(23W)), to 23.7±1.3 μmol m^(-2) s^(-1) with 23 W yellow light energy-saving light bulb (ELB-Y_(23W)), to 27.8±0.7 μmol m^(-2) s^(-1) with 10 W white light LED (light-emitting diode) (LED-W_(10W)), or to 31.3±2.7 μmol m^(-2) s^(-1) with 10W yellow light LED (LED-Y_(10W)). Results showed that plant growth rates of ＂Aglaonema＂ spp. var. 'Green peacock', ＂Aglaonema＂ spp. var. 'Pattaya beauty', and ＂Epipremnum aureum＂ were stimulated by additional lighting with LED-W_(10W), while plant growth of ＂Dieffenbachia＂ spp. var. 'Sparkles' was enhanced by both ELB-W_(23W) and LED-W_(10W). Plants of ＂Aglaonema＂ spp. var. 'Siam Aurora' were motivated by lighting with LED-W_(10W) and LED-Y_(10W), yet plants of ＂Spathiphyllum floribundum＂ were most provoked by ELB-W_(23W) and LED-Y_(10W). Along with the promotion of growth rate by the increase of light intensity, NFRC was also gradually improved by the extra light. At 5 wk after start of lighting treatments, NFRC increased to 1.5-3 folds than that at 2 wk. As a result, this study demonstrated that varietal differences in requirement and response to light intensity and quality existed in different ornamental plant species. Plant characteristics and indoor light environment are factors needed to be taken into account with other environmental conditions when selecting ornamental plants to grow indoors. To further improve plant growth as well as to raise NERC for purpose of consuming indoor carbon dioxide, increase of light intensity with artificial light sources is a proper option for consideration.