Quero José Luis, Villar Rafael, Marañón Teodoro, Zamora Regino
Grupo de Ecología Terrestre, Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, E-18071 Granada, Spain.
New Phytol. 2006;170(4):819-33. doi: 10.1111/j.1469-8137.2006.01713.x.
Here, we investigated the physiological and structural leaf responses of seedlings of two evergreen and two deciduous Quercus species, grown in a glasshouse and subjected to contrasted conditions of light (low, medium and high irradiance) and water (continuous watering vs 2-months drought). The impact of drought on photosynthetic rate was strongest in high irradiance, while the impact of shade on photosynthetic rate was strongest with high water supply, contradicting the hypothesis of allocation trade-off. Multivariate causal models were evaluated using d-sep method. The model that best fitted the dataset proposed that the variation in specific leaf area affects photosynthetic rate and leaf nitrogen concentration, and this trait determines stomatal conductance, which also affects photosynthetic rate. Shade conditions seemed to ameliorate, or at least not aggravate, the drought impact on oak seedlings, therefore, the drought response on leaf performance depended on the light environment.
在此，我们研究了两种常绿和两种落叶栎属植物幼苗的叶片生理和结构响应，这些幼苗在温室中生长，并处于光照（低、中、高辐照度）和水分（持续浇水与两个月干旱）的对比条件下。干旱对光合速率的影响在高辐照度下最强，而遮荫对光合速率的影响在高水分供应下最强，这与分配权衡假说相矛盾。使用d-sep方法评估多变量因果模型。最适合数据集的模型表明，比叶面积的变化影响光合速率和叶片氮浓度，并且该性状决定气孔导度，气孔导度也影响光合速率。遮荫条件似乎减轻了，或者至少没有加重干旱对橡树幼苗的影响，因此，叶片性能对干旱的响应取决于光照环境。
