Abstract：
The emission of potentially harmful compounds, including polycyclic aromatic hydrocarbons (PAHs), and the resulting air pollution is a serious problem in modern cities. It is therefore important to develop mitigation strategies, such as \"smart\" planting of trees that act as sinks for PAHs. However, the intra-individual (within-tree) variability in leaf PAH concentrations remains unknown. In this paper, we studied 15 ornamental apple trees (Malus × moerlandsii \'Profusion\') growing on a main street in a medium-sized city in Galicia (NW Spain). We determined the PAH concentrations at 12 canopy positions in each tree (2 orientations and 2 distances from the trunk at 3 heights), measured various ecological traits (specific leaf area [SLA], δ13C, stomatal density, fatty acid contents and leaf hairiness) and analyzed the variability in traits within the canopy in relation to PAH concentrations. We observed high intra-individual variability in the PAH concentrations and the leaf traits. Statistical analyses revealed that leaf height was the main source of variability both in the PAH concentrations and in the traits, mainly due to the leaf morphology, particularly to the SLA. Therefore, the ideal vegetation to remove PAHs would be high leaf biomass trees, not too tall and with a high proportion of shade leaves.
摘要：
潜在有害化合物的排放，包括多环芳烃(PAHs)，由此产生的空气污染是现代城市的一个严重问题。因此，重要的是制定缓解策略，例如“智能”种植作为多环芳烃水槽的树木。然而,叶片PAH浓度的个体内（树内）变异性仍然未知。在本文中,我们研究了15种观赏苹果树（Malus×moerlandsii\'Profusion\'），生长在加利西亚（西班牙西北部）的一个中型城市的主要街道上。我们确定了每棵树12个冠层位置的PAH浓度（2个方向和2个距离树干在3个高度），测量的各种生态性状(比叶面积[SLA]，δ13C,气孔密度，脂肪酸含量和叶片毛羽），并分析了冠层内性状与PAH浓度的关系。我们观察到PAH浓度和叶片性状的个体内变异性很高。统计分析表明，叶片高度是PAH浓度和性状变异性的主要来源，主要是由于叶片的形态，特别是SLA。因此,去除多环芳烃的理想植被是高叶片生物量的树木，不太高，阴叶比例很高。
