Alonso Conchita, Herrera Carlos M
Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas, Avda. María Luisa s/n Pabellón de Perú, E-41013 Seville, Spain.
New Phytol. 2003 Sep;159(3):645-656. doi: 10.1046/j.1469-8137.2003.00831.x.
• Here, we studied patterns of covariation of 10 leaf nutrients in expanding and mature leaves of the evergreen shrub Daphne laureola (Thymelaeaceae) in southern Spain. Changes in mean values and covariances of nutrients during leaf development may be relevant for plant fitness through herbivory if variation in leaf nutrients influences plant defoliation. • We analysed the between-population and developmental covariation of leaf nutrients by using common principal components (CPC) analysis. We also studied the relationships between leaf nutrient covariates and natural levels of plant defoliation. • Plants at our two study sites shared a CPC structure of covariation between concentrations of the leaf nutrients. Trends of nutrient covariation across individual plants were largely determined by between-plant variations in Ca concentration (CPC1), and by an 'overall nutrient status' gradient (CPC2) that was positively associated with major macronutrients (nitrogen, phosphorus and potassium), in both expanding and mature leaves. • Plant defoliation was positively related to scores on CPC2 for both expanding and mature leaves, indicating greater consumption on plants with balanced, high concentrations of nitrogen, phosphorus, potassium and calcium.
• 在此,我们研究了西班牙南部常绿灌木桂叶瑞香(瑞香科)正在展开的叶片和成熟叶片中10种叶片养分的协变模式。如果叶片养分的变化影响植物落叶,那么叶片发育过程中养分均值和协方差的变化可能通过食草作用与植物适合度相关。
• 我们使用共同主成分(CPC)分析来分析叶片养分的种群间和发育协变。我们还研究了叶片养分协变量与植物自然落叶水平之间的关系。
• 我们两个研究地点的植物在叶片养分浓度之间共享一种CPC协变结构。个体植物间养分协变趋势在很大程度上由钙浓度(CPC1)的植物间变异以及与主要大量养分(氮、磷和钾)呈正相关的“整体养分状况”梯度(CPC2)决定,这在正在展开的叶片和成熟叶片中均如此。
• 植物落叶与正在展开的叶片和成熟叶片在CPC2上的得分均呈正相关,表明对氮、磷、钾和钙浓度平衡且高的植物的啃食更多。