荔枝園潛熱及二氧化碳通量之研究

Latent Heat and CO2 Flux Measurement in the Litchi Orchard

姚銘輝(Ming-Hwi Yao) ； 陳俊仁(Chun-Jen Chen) ； 黃國祥(Guo-Sheng Huang)

《台灣農業研究》 60卷3期 (2011/09) Pp. 211-220

https://doi.org/10.6156/JTAR/2011.06003.06

摘要

本研究利用通量量測技術解決大面積監測果樹生理反應的限制，量測二氧化碳通量以瞭解荔枝（Litchi chinensis）果園植冠固碳能力，潛熱通量測值則代表果園實際蒸發散量。結果顯示，果園二氧化碳通量與太陽輻射量有直接關係（r＝0.87），並且與夜間溫度相關性亦高（r＝0.71）。潛熱則與以氣溫及相對濕度所計算之水汽壓差相關係數最高（r＝0.70），至於常用於果園之水份監測指標，包括土壤水分含量、莖幹汁液流速、葉片蒸散量及氣溫-葉溫差值，與潛熱通量相關性並不高。因此，水汽壓差資料可做為荔枝果園水份管理之指標。

關鍵字

荔枝 ； 潛熱 ； 二氧化碳通量 ； 能量平衡 ； 蒸發散

並列摘要

This research was conducted in the orchards of litchi (Litchi chinensis) to solve the problem of monitoring physiological responses of fruit trees in large field areas using the technique of flux measurement. Carbon dioxide flux was used to evaluate the carbon fixation capacity in litchi canopy. The value of latent heat flux can represent the actual evapotranspiration of the litchi orchard. Results of long term monitoring data collected in the orchard showed that the carbon dioxide flux was highly correlated to the solar radiation (r = 0.87) and the night temperature (r = 0.71). The latent heat flux was highly correlated to the vapor pressure deficit which was calculated by measuring temperature and relative humidity (r = 0.70). However, there were no good relationships between the latent heat flux and the commonly used water monitoring indices such as soil water content, sap flow in stem, leaf transpiration and values of differences between canopy temperature and air temperatures. Therefore, this study suggests that the vapor pressure deficit is a good index for the water management in litchi orchards.

並列關鍵字

Litchi ； Litchi chinensis ； Latent heat ； CO2 flux ； Energy balance ； Evapotranspiration