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

Although rarely assessed, small-scale heterogeneity in soil nutrient availability is suggested to be an important factor determining intraspecific variation in belowground plant resource acquisition strategies. We tested how increased resource availability and its small-scale (0.25 m2) spatial heterogeneity affect the nutrient acquisition strategy of Vaccinium myrtillus, a dominant ericoid shrub species in the forest understory, 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 three years, we applied spatially homogeneous and heterogeneous fertilization treatments (subplots of 6.25 m2 in ten sites of 1 ha) in a temperate forest in the Southern Black Forest (Germany). After three years, rooting uni..., , ## Metadata – Soil nutrient availability rather than spatial nutrient heterogeneity shapes the intraspecific response of root architectural, morphological, and mycorrhizal traits in *Vaccinium myrtillus* This submission includes one primary dataset associated with the manuscript: * **File:** `dataset_root_traits_Vmyrtillus.csv` * **Description:** Root traits for all samples collected for the submitted manuscript * **Dimensions:** 179 rows × 19 columns --- ## Dataset Structure ### Rows Each row represents a root sample of *Vaccinium myrtillus* collected in the field according to the methods described in the manuscript. ### Columns * **row_num**: row number from 1 to 179 #### Plot Information * **Plot**: Identifier for one of the ten plots (`CFB036`, `CFB053`, `CFB102`, `CFB110`, `CFB124`, `CFB137`, `CFB140`, `CFB162`, `CFB164`, `CFB173`) * **Subplot**: Numbered 1 to 6; each plot has 3 subplots (not fixed – based on *Vaccinium* cover) * **Sample number**: Sample identifiers from...,