ON-LINE MEASUREMENTS OF CO_2 AND H_2O GAS FLUXES, SAP FLUX AND EXPANSIVE GROWTH IN AN INTACT TOMATO FRUIT
ON-LINE MEASUREMENTS OF CO_2 AND H_2O GAS FLUXES, SAP FLUX AND EXPANSIVE GROWTH IN AN INTACT TOMATO FRUIT
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在线测量 CO_2 和 H_2O 气体通量、液流和完整番茄果实的膨胀生长
DOI：
10.1016/j.agrformet.2012.05.006
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发表时间：
1997
影响因子：
6.2
通讯作者：
江口 弘美
中科院分区：
文献类型：
--
作者：
M. Kitano;北野 雅治;T. Araki;荒木 卓哉;Michio Hamakoga;道男 濱古賀;H. Eguchi;江口 弘美
瞬态型顶篷室仍然是目前唯一可用的农业领域气体交换快速筛选的实用解决方案。该技术因其在测量过程中对冠层微气候的影响而受到批评，这会影响植物气体交换的运输机制和调节。将该技术与独立方法进行比较的实地研究仍然不完整。本研究的目的是量化室放置过程中物理环境的变化，确定最佳通量测量窗口，比较三种通量计算程序，并根据液流的独立测量测试该方法的性能。为此目的，在德国温带气候条件下进行了两项小麦实验。叶片蒸腾作用和液流在室部署后的前 120 秒内保持相对恒定，但随后发生了很大变化。因此，可以从该间隔期间的浓度测量系列推断冠层 H2O 通量。将之前文献中未提及的饱和函数与常用的常数和二次回归方法进行比较，并确定为计算蒸汽通量的最合适方法。研究再次证实，计算间隔期间CO2浓度的小比例变化有利于应用常用的二次回归方法来计算CO2通量。室移除后，液流、叶片和冠层气体交换受到严重干扰。需要相应地计划相同样本位置的重访时间。该研究证实，瞬态室技术可用于确定冠层气体交换，前提是确定浓度测量系列内的特征时间间隔并测试其非线性以建立适当的通量计算程序。
Transient type canopy chambers are still the only currently available practical solution for rapid screening of gas-exchange in agricultural fields. The technique has been criticized for its effect on canopy microclimate during measurement which affects the transport regime and regulation of plant gas-exchange. Field studies in which the technique has been compared against independent methods are still fragmentary. The aims of this study were to quantify the changes of the physical environment during chamber placement, to determine optimum flux measuring windows, to compare three flux-calculation procedures, and to test the performance of the method against independent measurements of sap-flow. Two wheat experiments were conducted for these purposes under German temperate climate conditions. Leaf transpiration and sap-flow remained relatively constant during the first 120s after chamber deployment, but changed considerably afterwards. Canopy H2O fluxes could thus be inferred from concentration measurement series during this interval. A saturation function, previously not mentioned in the literature, was compared against the commonly used constant and quadratic regression methods and identified as the most suitable method for calculating vapor fluxes. The study reconfirmed that small proportional changes of CO2concentrations during the calculation interval facilitate the application of the frequently applied quadratic regression method for calculating CO2fluxes. Sap-flow, leaf and canopy gas-exchange were severely perturbed after chamber removal. Revisiting times of same sample locations need to be planned accordingly. The study confirms that the transient chamber technique can be applied for determining canopy gas-exchange, provided that characteristic time intervals within concentration measuring series are determined and their non-linearity tested to establish appropriate flux calculation procedures.