Institute of Botany, Czech Academy of Sciences, CZ-252 43, Průhonice, Czech Republic.
Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 01, Praha 2, Czech Republic.
New Phytol. 2022 Sep;235(6):2223-2236. doi: 10.1111/nph.18132. Epub 2022 Apr 23.
The efficient uptake of nutrients depends on the ability of roots to respond to gradients of these resources. Although pot experiments have shown that species differ in their ability to proliferate their roots in nutrient-rich patches, the role of such differences in determining root shapes in the field is unclear. We used fine-scale quantitative (q)PCR-based species-specific mapping of roots in a grassland community to reconstruct species-specific root system shapes. We linked them with data from pot experiments on the ability of these species to proliferate in nutrient-rich patches and their rooting depth. We found remarkable diversity in root system shapes, from cylindrical to conical. Interspecific differences in rooting depths in pots were the main determinant of rooting depths in the field, whereas differences in foraging ability played only a minor role. Although some species with strong foraging ability did place their roots into nutrient-rich soil layers, it was not a universal pattern. The results imply that although the vertical differentiation of grassland species is pronounced, it is primarily not driven by the differential plastic response of species to soil nutrient gradients. This may constrain the coexistence of species with similar rooting depths and may instead favour coexistence of species differing in their architectural blueprints.
养分的有效吸收取决于根系响应这些资源梯度的能力。虽然盆栽实验表明，物种在富营养斑块中根系增殖的能力存在差异，但这种差异在确定野外根系形状中的作用尚不清楚。我们使用基于精细定量（q）PCR 的方法对草原群落中的物种特异性根系进行了特异性映射，以重建物种特异性的根系形状。我们将它们与这些物种在富营养斑块中增殖能力和根系深度的盆栽实验数据联系起来。我们发现根系形状存在显著的多样性，从圆柱形到圆锥形。盆栽中物种间的根系深度差异是野外根系深度的主要决定因素，而觅食能力的差异只起次要作用。尽管一些具有较强觅食能力的物种确实将其根系置于富营养土壤层中，但这不是普遍模式。研究结果表明，尽管草原物种的垂直分化很明显，但它主要不是由物种对土壤养分梯度的差异可塑性反应驱动的。这可能限制了具有相似根系深度的物种的共存，而有利于在建筑蓝图上存在差异的物种共存。
