The Influence of Light and Temperature on Isoprene Emission Rates from Live Oak
The Influence of Light and Temperature on Isoprene Emission Rates from Live Oak
复制标题
光和温度对活橡树异戊二烯释放率的影响
DOI：
10.1111/j.1399-3054.1979.tb03200.x
复制
发表时间：
1979
影响因子：
6.4
通讯作者：
W. F. Burns
中科院分区：
文献类型：
--
作者：
D. Tingey;M. Manning;L. Grothaus;W. F. Burns
人们越来越意识到植物作为活性碳氢化合物的来源所起的作用，这些活性碳氢化合物可能是光化学氧化剂前体。一项研究旨在独立评估可变的光和温度对活橡树(Quercus virginiana Mill.)异戊二烯排放的影响。植物在生长室中进行调节，然后转移到环境控制的气体交换室。采集了舱内空气样品；异戊二烯经低温浓缩后用气相色谱测定。使用Logistic函数对异戊二烯的排放速率进行了建模。在低温(20℃)或黑暗条件下，异戊二烯的排放量最低。随着温度和光照强度的增加，异戊二烯的释放速率增大，在80 0μEm-2、S-1和40~44℃时分别达到最大值。更高的温度导致排放量大幅下降。由于异戊二烯的排放在中等强度下是光饱和的，温度似乎是一天中大部分时间控制排放的主要因素。根据光强和温度的不同，异戊二烯排放造成的碳损失占光合作用固定碳的0.1%到2%。
There is a growing awareness of the role of vegetation as a source of reactive hydrocarbons that may serve as photochemical oxidant precursors. A study was designed to assess independently the influence of variable light and temperature on isoprene emissions from live oak (Quercus virginiana Mill.). Plants were conditioned in a growth chamber and then transferred to an environmentally controlled gas-exchange chamber. Samples of the chamber atmosphere were collected; isoprene was concentrated cryogenically and measured by gas chromatography. A logistic function was used to model isoprene emission rates. Under regimes of low temperature (20°C) or darkness, isoprene emissions were lowest. With increasing temperature or light intensity, the rate of isoprene emission increased, reaching maxima at 800 μE m-2 s-1 and 40–44°C, respectively. Higher temperatures caused a large decrease in emissions. Since the emissions of isoprene were light-saturated at moderate intensities, temperature appeared to be the main factor controlling emissions during most of the day. Carbon lost through isoprene emissions accounted for 0.1 to 2% of the carbon fixed during photosynthesis depending on light intensity and temperature.