Oechel Walter C, Lawrence William T
Department of Biology, McGill University, H3A 1B1, Montreal, Quebec, Canada.
Oecologia. 1979 Jan;39(3):321-335. doi: 10.1007/BF00345443.
A transportable system for field and laboratory measurement of plant CO exchange and transpiration is described. A computer based data acquisition system which controls data-logging has been successfully proven in mediterranean zones of central Chile and southern California and in the taiga of central Alaska. Six Peltier-effect cooled acrylic plastic chambers are utilized in an open infrared gas analysis system for continuous monitoring of CO exchange. Chamber air temperatures automatically track ambient air temperatures or can be preset to maintain a constant temperature. Use of Peltier-effect cooling modules and electric cartridge heaters result in light-weight chambers and heat exchange units with low power requirements. No refrigeration or liquid coolant is required under most operating conditions. A unique sampling method using natural illumination and six chambers allows highly replicated determinations of the temperature and light dependence of photosynthesis and/or respiration to be made over the course of a 6-d sampling period. Measurements are made continuously 24 h/day. Diurnal CO exchange patterns are determined from one chamber that tracks the ambient air temperature. The other five chambers have air temperatures fixed at distinct levels over a 35° C range. Each day the chambers are changed to another temperature level according to a randomized sampling pattern. All the data are pooled at the end of the 6-d run to construct the light and temperature response surfaces of CO exchange typical of the individuals sampled. Simultaneous determinations of conductance, leaf temperature, air temperature, and light are made.
本文描述了一种用于野外和实验室测量植物二氧化碳交换及蒸腾作用的便携式系统。一个基于计算机的数据采集系统，其控制数据记录功能已在智利中部和加利福尼亚南部的地中海地区以及阿拉斯加中部的泰加林成功得到验证。在一个开放式红外气体分析系统中使用了六个珀尔帖效应冷却的丙烯酸塑料气室，用于连续监测二氧化碳交换。气室空气温度可自动跟踪环境空气温度，也可预设为保持恒定温度。使用珀尔帖效应冷却模块和电加热丝，使得气室和热交换单元重量轻且功率需求低。在大多数运行条件下无需制冷或液体冷却剂。一种独特的采样方法，利用自然光照和六个气室，能够在为期6天的采样期间内对光合作用和/或呼吸作用的温度和光依赖性进行高度重复的测定。测量每天24小时连续进行。从一个跟踪环境空气温度的气室确定昼夜二氧化碳交换模式。其他五个气室的空气温度在35°C范围内固定在不同水平。每天根据随机采样模式将气室更换到另一个温度水平。在6天的运行结束时汇总所有数据，以构建所采样个体典型的二氧化碳交换的光和温度响应曲面。同时测定导度、叶片温度、空气温度和光照。
