Seasonal fluctuations and temperature dependence of leaf gas exchange parameters of co-occurring evergreen and deciduous trees in a temperate broad-leaved forest
Seasonal fluctuations and temperature dependence of leaf gas exchange parameters of co-occurring evergreen and deciduous trees in a temperate broad-leaved forest
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DOI：
10.1093/treephys/26.9.1173
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发表时间：
2006-09-01
期刊：
影响因子：
4
通讯作者：
Matsuo, Naoko
中科院分区：
文献类型：
--
作者：
Kosugi, Yoshiko;Matsuo, Naoko
研究了3种常绿树种(Quercus gluca Thunb.、Cinnamomum Camphora Sieb.)叶片气体交换参数的季节变化。和锥栗)和1个落叶栎属(Quercus serrata Thunb.)温带阔叶林中共生的优势树种。从瞬时田间气体交换数据(一点法)反推得到暗呼吸速率(R-n)、最大羧化速率(V-CMAX)和气孔系数(M)，即气孔导度与净同化率的比值(经水汽压亏缺和内部二氧化碳浓度校正后)。分析了25℃参考温度下R-n和V-cmax的归一化值(R-n25，V-cmax 25)及其温度依赖关系(Delta H-a(R-n)，Delta H-a(V-cmax))。参数V-cmax 25：24.0-40.3mumolm(-2)，S(-1)，Delta H-a(V-Cmax)29.1-67.0kJ(-1)。参数R-n25的变化范围为0.6-1.4u molm(-2)，S参数的变化范围为47.4-95.4U molm(-1)，Delta H-a的变化范围为47.4-95.4U moL(-1)。气孔系数在7.2~8.2之间。对于三种常绿树木，一组V-cmax 25和R-n25 C参数和温度依赖曲线对全年的碳吸收做出了令人满意的估计，但同时发生在4月和5月的落叶和展叶期间除外。在落叶栎树中，V-cmx25在夏季后下降，同时V-cmax 25和R-n25在叶展开期间发生变化。在所有物种中，在模拟研究中应考虑叶片展开和干旱期间的In变化。因此，在建立常绿阔叶树种碳吸收模型时，需要考虑叶片展开和干旱时期归一化气体交换参数的变化。
Seasonal fluctuations in leaf gas exchange parameters were investigated in three evergreen (Quercus glauca Thunb., Cinnamomum camphora Sieb. and Castanopsis cuspidata Schottky) and one deciduous (Quercus serrata Thunb.) co-occurring, dominant tree species in a temperate broadleaved forest. Dark respiration rate (R-n), maximum carboxylation rate (V-cmax) and stomatal coefficient (m), the ratio of stomatal conductance to net assimilation rate after adjustment to the vapor pressure deficit and internal carbon dioxide (CO2) concentration, were derived inversely from instantaneous field gas exchange data (one-point method). The normalized values of R-n and V-cmax at the reference temperature of 25 degrees C (R-n25, V-cmax25) and their temperature dependencies (Delta H-a(R-n), Delta H-a(V-cmax)) were analyzed. Parameter V-cmax25 ;ranged from 24.0 - 40.3 mu mol m(-2) s(-1) and Delta H-a(V-cmax) ranged from 29.1 - 67.0 kJ mol(-1). Parameter R-n25 ranged from 0.6 - 1.4 mu mol m(-2) s(-1) and Delta H-a(R-n) ranged from 47.4 - 95.4 U mol(-1). The stomatal coefficient ranged from 7.2 - 8.2. For the three evergreen trees, a single Set of V-cmax25 and R-n25 C parameters and temperature dependence curves produced satisfactory estimates of carbon uptake throughout the year, except during the period of simultaneous leaf fall and leaf expansion, which occurs in April and May. In the deciduous oak, declines in V-cmx25 were observed after summer, along with changes in V-cmax25 and R-n25 during the leaf expansion period. In all species, variation in in during periods of leaf expansion and drought should be considered in modeling studies. We conclude that the changes in normalized gas exchange parameters during periods of leaf expansion and drought need to be considered when modeling carbon uptake of evergreen broad-leaved species.