Soil nutrient availability rather than spatial nutrient heterogeneity shapes the intraspecific response of root architectural, morphological and mycorrhizal traits in Vaccinium myrtillus

作者：Barbara Meyers, Rodrigue Friaud, Denicia Kassie, Michael Scherer‐Lorenzen, Grégoire T. Freschet · 发表于：Journal of Ecology · 年份：2025 · DOI：10.1111/1365-2745.70188 · 被引用次数：2 · 研究领域：Plant nutrient uptake and metabolism、Mycorrhizal Fungi and Plant Interactions、Soil Carbon and Nitrogen Dynamics

Abstract Although rarely assessed, small‐scale heterogeneity in soil nutrient availability is suggested to be an important factor determining intraspecific variation in below‐ground plant resource acquisition strategies. We tested how increased resource availability and its small‐scale (0.25 m 2 ) spatial heterogeneity affect the nutrient acquisition strategy of Vaccinium myrtillus , a dominant ericoid shrub species in the forest understorey, by quantifying intraspecific root trait variation in an extensive set of root traits associated with nutrient acquisition. We hypothesized that increased nutrient availability would constrain the expression of traits that enhance nutrient acquisition, whereas spatial nutrient heterogeneity would promote a diversity of root trait values. Over 3 years, we applied spatially homogeneous and heterogeneous fertilization treatments (subplots of 6.25 m 2 in 10 sites of 1 ha) in a temperate forest in the Southern Black Forest (Germany). After 3 years, rooting units of Vaccinium myrtillus were sampled, and nine traits representing complementary aspects of nutrient uptake strategies were quantified, including aspects of root morphology, architecture and mycorrhizal association. Increased nutrient availability induced intraspecific trait adjustments: specific root length and mycorrhizal colonization were reduced, whereas root diameter, tissue density and branching intensity increased, suggesting a shift in plant investment strategies for nutrient ac...