Liu Yan, Cordero Irene, Bardgett Richard D
Department of Earth and Environmental Sciences The University of Manchester Manchester UK.
Department of Community Ecology Swiss Federal Institute for Forest, Snow and Landscape Research WSL Birmensdorf Switzerland.
J Ecol. 2023 Dec;111(12):2733-2749. doi: 10.1111/1365-2745.14215. Epub 2023 Oct 25.
Root functional traits are known to influence soil properties that underpin ecosystem functioning. Yet few studies have explored how root traits simultaneously influence physical, chemical, and biological properties of soil, or how these responses are modified by common grassland perturbations that shape roots, such as defoliation and fertilisation.Here, we explored how root traits of a wide range of grassland plant species with contrasting resource acquisition strategies (i.e. conservative vs. exploitative strategy plant species) respond to defoliation and fertilisation individually and in combination, and examined cascading impacts on a range of soil abiotic and biotic properties that underpin ecosystem functioning.We found that the amplitude of the response of root traits to defoliation and fertilisation varied among plant species, in most cases independently of plant resource acquisition strategies. However, the direction of the root trait responses (increase or decrease) to perturbations was consistent across all plant species, with defoliation and fertilisation exerting opposing effects on root traits. Specific root length increased relative to non-perturbed control in response to defoliation, while root biomass, root mass density, and root length density decreased. Fertilisation induced the opposite responses. We also found that both defoliation and fertilisation individually enhanced the role of root traits in regulating soil biotic and abiotic properties, especially soil aggregate stability. : Our results indicate that defoliation and fertilisation, two common grassland perturbations, have contrasting impacts on root traits of grassland plant species, with direct and indirect short-term consequences for a wide range of soil abiotic and biotic properties that underpin ecosystem functioning.
根系功能性状会影响支撑生态系统功能的土壤属性，这是已知的。然而，很少有研究探讨根系性状如何同时影响土壤的物理、化学和生物学属性，或者这些响应如何因塑造根系的常见草地扰动（如去叶和施肥）而改变。在这里，我们探究了具有不同资源获取策略（即保守型与开拓型策略植物物种）的多种草地植物物种的根系性状如何分别及共同响应去叶和施肥，并研究了对一系列支撑生态系统功能的土壤非生物和生物属性的级联影响。我们发现，根系性状对去叶和施肥的响应幅度在不同植物物种间存在差异，在大多数情况下与植物资源获取策略无关。然而，根系性状对扰动的响应方向（增加或减少）在所有植物物种中是一致的，去叶和施肥对根系性状产生相反的影响。相对于未受扰动的对照，去叶会使比根长增加，而根生物量、根质量密度和根长度密度则会降低。施肥则引发相反的响应。我们还发现，去叶和施肥各自都增强了根系性状在调节土壤生物和非生物属性方面所起的作用，尤其是土壤团聚体稳定性。我们的研究结果表明，去叶和施肥这两种常见的草地扰动，对草地植物物种的根系性状有着相反的影响，对一系列支撑生态系统功能广泛的土壤非生物和生物属性具有直接和间接的短期影响。
