群落生物環境反応測定装置によるオオムギ群落における試験観測結果について

A system designed to measure the vegetation response to environment was constructed on the basis of the eddy correlation method.It consisted of two sets of a small rapid response sensors; three dimensional sonic anemometer thermometers and infrared CO2-humidity fluctuation meters,and a personal computer for data acquisition. Field tests of the system were made over a barley field in April and May,1990.The turbulent fluxes obtained by two sets of flux measuring system mounted at the same height were in fair agreement. The turbulent fluxes(momentum,sensible heat,latent heat and carbon dioxide) measured at two height wihtin and above plant cannopies and their differences showed realistic diurnal variations.The direction and magnitude of each flux varied depending on the srength or distribution of source and sink within plant canopies. These findings confirmed that this measureing system is promising for quantitative estimate of vegetation response such as transpiration, photosynthesis and respiration in certain canopy layers to environmental variations.

植物群落内外の二高度で運動量、顕熱、炭酸ガス、水蒸気量の乱流輸送量を同時に測定し、二高度間の輸送量の収束、発散量を評価できる群落生物環境反応測定装置の概要とオオムギ群落における試験観測の結果について報告した。以下に得られた結果の主なものを列挙する。1）群落上の同一高度に二組の乱流輸送測定機器を設置し、乱流輸送量の比較観測を行った。それぞれの装置で得られた運動量、顕熱、潜熱などの輸送量の間には系統だった差異のないことが示された。2）オオムギ群落内外に機器を設置して、二高度で乱流輸送量を測定し、その収束量や発散量の経時変化も調べた。得られた結果は植被層上部の能動層の存在など群落で期待される定性的な特性と一致した。