Villar Rafael, Robleto Jeannette Ruiz, De Jong Yvonne, Poorter Hendrik
Area de Ecología, Dpto de Botánica, Ecologia y Fisiologia Vegetal, Universidad de Córdoba, Spain.
Plant Cell Environ. 2006 Aug;29(8):1629-43. doi: 10.1111/j.1365-3040.2006.01540.x.
We tested to what extent differences in construction costs (CC) and chemical composition of woody species are attributed to leaf habit. Eight evergreen and eight deciduous species belonging to six families were selected to form eight phylogenetic independent contrasts (PICs). The plants were grown from seed in a glasshouse. Differences in leaf, stem and root CC between evergreen and deciduous species were minor, the proportion of variance explained by leaf habit generally being less than 6%. Surprisingly, differences in leaf chemical composition between deciduous and evergreen species were small as well. Variation in CC and chemical composition among families was substantial, the factor 'family' explaining 50-85% of variance. We therefore conclude that in this case, phylogeny is a more important factor than functional group. Leaves of the fast-growing species in this experiment showed high levels of minerals, organic acids, proteins and lipids, whereas leaves of the slow-growing species had higher concentrations of soluble phenolics, lignin as well as higher carbon/nitrogen (C/N) ratio. These relationships suggest a trade-off between growth and defence. In contrast, CC of leaves, stems, roots or whole plants showed no or only a weak correlation with relative growth rate (RGR). The C/N ratio of the leaves is an easily measured parameter that correlated strongly in a negative way with the RGR of the plants and reflected better the balance between investment in structure and physiological functioning than CC.
我们测试了木本植物的建筑成本（CC）和化学成分差异在多大程度上归因于叶习性。从六个科中挑选了八种常绿和八种落叶物种，以形成八个系统发育独立对比（PIC）。这些植物由种子在温室中培育而成。常绿和落叶物种之间叶、茎和根的CC差异较小，叶习性解释的方差比例通常小于6%。令人惊讶的是，落叶和常绿物种之间的叶化学成分差异也很小。科之间CC和化学成分的变异很大，“科”这一因素解释了50 - 85%的方差。因此我们得出结论，在这种情况下，系统发育比功能组是更重要的因素。本实验中生长迅速的物种的叶片显示出高水平的矿物质、有机酸、蛋白质和脂质，而生长缓慢的物种的叶片具有更高浓度的可溶性酚类、木质素以及更高的碳/氮（C/N）比。这些关系表明生长与防御之间存在权衡。相比之下，叶、茎、根或整株植物的CC与相对生长速率（RGR）没有相关性或只有微弱的相关性。叶片的C/N比是一个易于测量的参数，它与植物的RGR呈强烈负相关，并且比CC更能反映结构投资与生理功能之间的平衡。
