本研究的目的是利用樹液流觀測法來估算植物蒸散量，同時結合無線感測器網路(Wireless sensor network, WSN)裝置建構一套無線化樹液流觀測系統。集水區內蒸散量的變化會影響植物需水量之推估，對於水文過程影響相當大，合適的蒸散量觀測將可以提供決策者對於可用水量之掌握。首先利用自製熱消散式樹液探針估算植物蒸散量，再整合無線感測器節點與樹液探針建立無線化觀測方式，透過無線化的方式收集不同地點的觀測資料，以減輕野外收集資料之人力需求。
利用樹液探針所收集的溫度資料可以估算該植物內的樹液流速，配合植物邊材面積和樹冠下遮蔽面積即可推算出植物的蒸散量，自製的熱消散式樹液探針經率定修正後，藉由蒸散量驗證實驗可以驗證其估算蒸散量之能力。在開發無線化樹液流觀測系統過程中，利用具有智能網路與低耗能的無線感測器網路裝置來收集樹液探針的溫度訊號，針對野外使用所需要的長時間電力與溫度訊號微弱而不易接收等問題，利用自行開發的整合電路介面，建立無線化樹液流觀測裝置，觀測壽命因此提升三倍並解決訊號接收問題。
在使用無線化樹液流觀測系統時，發現無線系統收集的溫度資料與實際溫度之間有時間和量值上的誤差，也間接造成樹液流的估算誤差。發現主要是整合電路介面在轉換溫度資訊時會受到環境溫度的影響，可以藉由無線感測器和資料記錄器所收集到的其他相關溫度資料來修正樹液探針的溫度資料，以修正無線化樹液流之觀測結果。

The aim of this study is to develop a new method of sap flow system, namely wireless sap flow observing system by applying two study methods: sap flow observation and wireless sensor network in the calculation of the transpiration in trees.
This study used Thermal dissipation method to measure sap flow in trees with self-made sap probes which were calibrated before setting up at the observation field. With the temperature signals collected by sap probes, the transpiration could be calculated by substituting sap flow, sapwood area, and ground area into the calculation formula. Then, the verification experiment was carried out in the lab in order to compare the transpiration that calculated from sap flow and from actual situation.
Problems occurred during the measurement with sap probes associated with wireless sensor network at the observation field. The problems were electrical power, signal transduction, and inaccuracy of calculated transpiration. Therefore, this study discussed the source of error and tried to solve them.
The results showed that the transpiration calculated by thermal dissipation method was close to the actual transpiration in trees, and the application problems of wireless sensor network at the observation field would be improved. Furthermore, this study calibrated the error in evapotranpiration estimated by wireless sensor network, and the error could be revised roughly. Suggestions were also provided in this study for the revision results.

1. 吳聲沅， (2008)， 利用樹液探針研究環境參數對植物蒸散之影響， 國立中央大學土木工程研究所碩士論文。
2. 李光敦， (2003)， 水文學， 五南圖書出版有限公司， 89-103。
3. 侯智雄， (2008)， 北東眼山溫帶常綠闊葉林木本植物社會11年期動態， 靜宜大學生態學系碩士論文。
4. 洪志凱， (2004)， 樹液探針之發展與應用， 國立台灣科技大學機械工程所碩士論文。
5. 康紹忠、劉曉明、熊傳章， (1994)， 土壤-植物-大氣連續體水分傳輸理論及其應用， 水力電力出版社， 52-84。
6. 郭振民，(2009)，「整合為星遙測與無線化樹汁流觀測推估區域蒸發散」，國立成功大學水利及海洋工程研究所博士論文。
7. 郭耀綸， (2005)， 風對南仁山不同生育地分佈樹種苗木氣孔導度與蒸蒸散率的影響， 國立屏東大學森林系碩士論文。
8. 陳育閔， (2008)， 無線感測器網路節能策略的研究， 國立雲林科技大學電機工程研究所碩士論文。
9. 陳信雄， (1983)， 森林水文學， 千華出版公司， 163-168。
10. 陳俐如， (2005)， 鴛鴦湖地區台灣扁柏樹液流動之探討， 國立東華大學自然資源管理研究所碩士論文。
11. 羅勻謙， (2004)， 鴛鴦湖地區台灣扁柏森林生態系蒸散作用之研究， 國立東華大學自然資源管理研究所碩士論文。
12. Benyon, R. G. (1999). Nighttime water use in an irrigated Eucalyptus grandis plantation. Tree Physiology, 19(13), 853-859.
13. Cao, X. H., Chen, J. M., Zhang, Y., and Sun, Y. X. (2008). Development of an integrated wireless sensor network micro-environmental monitoring system. Isa Transactions, 47(3), 247-255.
14. Cardell-Oliver, R., Kranz, M., Smettem, K., and Mayer, K. (2005). A reactive soil moisture sensor network: Design and field evaluation. International Journal of Distributed Sensor Networks, 1(2), 149-162.
15. Cermak, J., Deml, M., & Penka, M. (1973). New method of sap flow-rate determination in trees. Biologia Plantarum, 15(3), 171-178.
16. Cermak, J., and Nadezhdina, N. (1998). Sapwood as the scaling parameter defining according to xylem water content or radial pattern of sap flow? Annales Des Sciences Forestieres, 55(5), 509-521.
17. Clearwater, M. J., Meinzer, F. C., Andrade, J. L., Goldstein, G., & Holbrook, N. M. (1999). Potential errors in measurement of nonuniform sap flow using heat dissipation probes. Tree Physiology, 19(10), 681-687.
18. Cochard H., N. Breda and A. Granier(1996). Whole tree hydraulic conductance and water loss regration in Quercus during drought : evidence for stomatal control of embolism? Annales des Science Forestieres 53, 197-206.
19. Do, F., and Rocheteau, A. (2002a). Influence of natural temperature gradients on measurements of xylem sap flow with thermal dissipation probes. 1. Field observations and possible remedies. Tree Physiology, 22(9), 641-648.
20. Do, F., and Rocheteau, A. (2002b). Influence of natural temperature gradients on measurements of xylem sap flow with thermal dissipation probes. 2. Advantages and calibration of a noncontinuous heating system. Tree Physiology, 22(9), 649-654.
21. Donovan, L. A., Grise, D. J., West, J. B., Pappert, R. A., Alder, N. N., & Richards, J. H. (1999). Predawn disequilibrium between plant and soil water potentials in two cold-desert shrubs. Oecologia, 120(2), 209-217.
22. Fisher, J. B., Baldocchi, D. D., Misson, L., Dawson, T. E., & Goldstein, A. H. (2007). What the towers don't see at night: nocturnal sap flow in trees and shrubs at two AmeriFlux sites in California. Tree Physiology, 27(4), 597-610.
23. Granier, A. (1987a). Evaluation of transpiration in a douglas-fir stand by means of sap flow measurements. Tree Physiology, 3(4), 309-319.
24. Hogg, E. H., and Hurdle, P. A. (1997). Sap flow in trembling aspen: implications for stomatal responses to vapor pressure deficit. Tree Physiology, 17(8-9), 501-509.
25. Hua, C. Q., and Yum, T. S. P. (2006). Maximum lifetime routing and data aggregation for wireless sensor networks. In F. Boavida, T. Plagemann, B. Stiller, C. Westphal & E. Monteiro (Eds.), Networking 2006: Networking Technologies, Services, and Protocols; Performance of Computer and Communication Networks; Mobile and Wireless Communications Systems, 3976, 840-855.
26. Kline, J. R., Reed, K. L., Waring, R. H., & Stewart, M. L. (1976). Field measurement of transpiration in Douglas-fir. Journal of Applied Ecology, 13(1), 273-283.
27. Matese, A., Di Gennaro, S. F., Zaldei, A., Genesio, L., and Vaccari, F. P. (2009). A wireless sensor network for precision viticulture: The NAV system. Computers and Electronics in Agriculture, 69(1), 51-58.
28. Novick, K. A., Oren, R., Stoy, P. C., Siqueira, M. B. S., and Katul, G. G. (2009). Nocturnal evapotranspiration in eddy-covariance records from three co-located ecosystems in the Southeastern US: Implications for annual fluxes. Agricultural and Forest Meteorology, 149(9), 1491-1504.
29. Oleary, J. W. (1970). Can there be a positive water potential in plants. Bioscience, 20(15), 858-859.
30. Phillips, N., Bond, B. J., McDowell, N. G., and Ryan, M. G. (2002). Canopy and hydraulic conductance in young, mature and old Douglas-fir trees. Tree Physiology, 22(2-3), 205-211.
31. Saugier, B., Granier, A., Pontailler, J. Y., Dufrene, E., and Baldocchi, D. D. (1997). Transpiration of a boreal pine forest measured by branch bag, sap flow and micrometeorological methods. Tree Physiology, 17(8-9), 511-519.
32. Sevanto S., Mikkelsen, T.N., Pilegaard K., Vesala T. (2003) Comparison of tree stem diameter variations in beech (Fagus sylvatica L.) in Soro Denmark and in Scots pine (Pinus sylvestris L.) in Hyytiala, Finland. Boreal environment research, 8(4), 457-464.
33. Siqueira, M., Katul, G., and Porporato, A. (2008). Onset of water stress, hysteresis in plant conductance, and hydraulic lift: Scaling soil water dynamics from millimeters to meters. Water Resources Research, 44(1). 10.1029/2007WR006094
34. Smith, D. M., and Allen, S. J. (1996). Measurement of sap flow in plant stems. Journal of Experimental Botany, 47(305), 1833-1844.
35. Snyder, K. A., Richards, J. H., and Donovan, L. A. (2003). Night-time conductance in C-3 and C-4 species: do plants lose water at night? Journal of Experimental Botany, 54(383), 861-865.
36. Tian, D., & Georganas, N. D. (2003). A node scheduling scheme for energy conservation in large wireless sensor networks. Wireless Communications & Mobile Computing, 3(2), 271-290.
37. Vellidis, G., Tucker, M., Perry, C., Wen, C., & Bednarz, C. (2008). A real-time wireless smart sensor array for scheduling irrigation. Computers and Electronics in Agriculture, 61(1), 44-50.
38. Wilson, K. B., Hanson, P. J., Mulholland, P. J., Baldocchi, D. D., and Wullschleger, S. D. (2001). A comparison of methods for determining forest evapotranspiration and its components: sap-flow, soil water budget, eddy covariance and catchment water balance. Agricultural and Forest Meteorology, 106(2), 153-168.
39. Wullschleger, S. D., Hanson, P. J., and Todd, D. E. (2001). Transpiration from a multi-species deciduous forest as estimated by xylem sap flow techniques. Forest Ecology and Management, 143(1-3), 205-213.
40. Yang, Y. Y., and Cardei, M. (2010). Adaptive energy efficient sensor scheduling for wireless sensor networks. Optimization Letters, 4(3), 359-369.