DOI: 10.5061/dryad.sxksn03fs
title: Phylogeny overrides environmental effects in explaining leaf and root nutrient concentrations in Fabaceae

description: Plant nutrients are essential for plant growth and ecosystem functioning.
 While Fabaceae plants are ecologically and economically significant, the
 phylogenetic and environmental controls on their leaf and root nutrient
 concentrations at a large scale have not been extensively studied. We
 measured six nutrient concentrations (N, P, S, K, Ca, and Mg) in both the
 leaves and roots of 121 Fabaceae species across various vegetation types
 in China. The scaling exponents between leaves and roots showed that N-N
 and P-P were significantly less than 1, Ca-Ca was significantly greater
 than 1, and S-S, K-K, and Mg-Mg did not significantly differ from 1,
 indicating divergent nutrient allocation strategies between leaves and
 roots. For most nutrients, phylogeny explained a larger proportion of the
 variation than environmental factors. However, for leaf P and K,
 environmental variables accounted for more variation than phylogeny, with
 mean annual temperature being the strongest environmental predictor for
 both. This suggests that these two nutrients may play a particularly
 important role in the environmental adaptation of Fabaceae species.
 Synthesis. This study revealed contrasting nutrient allometries
 between leaves and roots of Fabaceae plants, clarified the relationships
 between nutrients and environmental variables, and highlighted the
 dominant role of phylogeny in explaining nutrient variation. Together,
 these findings enhance our understanding of the biogeographic distribution
 of Fabaceae species and offer insights into their adaptive responses to
 environmental change across broad spatial scales.
description: <strong>Study sites and vegetation
 types</strong> We selected 88 representative
 natural ecosystems across China for this study. The sites span latitudes
 from 18.38°N to 53.3°N and longitudes from 75.47°E to 128.9°E, covering a
 wide range of vegetation types in the Northern Hemisphere. These include
 cold-temperate coniferous forests, temperate coniferous and broad-leaved
 mixed forests, warm temperate deciduous broad-leaved forests, subtropical
 evergreen broad-leaved forests, tropical rainforests, temperate steppes,
 temperate deserts, and the alpine vegetation of the Qinghai-Tibetan
 Plateau (Fig. 1). <strong>2.2 Field design and
 plot establish</strong> From 2013 to 2022,
 samples were collected in July and August, during peak vegetation growth.
 Sampling occurred in well-protected national nature reserves, ecological
 observatory sites, or natural vegetation areas with minimal human
 disturbance (Liu et al., 2023, Liu et al., 2022). In forested areas, three
 or four experimental plots (30 m × 40 m) were established. Within each
 plot, one or two shrub subplots (5 × 5 m) and two or four herb subplots (1
 × 1 m) were nested. In grassland ecosystems, eight plots (1 m × 1 m) were
 set up at each site. For desert ecosystems, six shrub plots (10 m × 10 m)
 and eight herb plots (1 × 1 m) were established (Yan et al., 2023, Zhang
 et al., 2021). In 34 sites, we did not conduct surveys of community
 structure; instead, we directly collected samples of the target plants.
 Coordinates and elevations of sample sites were recorded using GPS on
 smartphones. The field surveys encompassed 331 Fabaceae species-site
 combinations, representing 121 species across 50 genera (Table
 S1-2). <strong>2.3 Root and leaf sampling
 </strong> Leaf samples from Fabaceae species were
 taken from fully expanded, typical, and healthy plants. To accurately
 sample roots from woody species, we first loosened the soil around the
 target plant and traced the roots to the stem. Fine roots (diameter
 &lt; 2 mm) were then carefully collected, cleaned of soil, and
 prepared for analysis. Leaf and root samples were collected from at least
 three individuals per species, mixed, and dried in an oven at 60 °C until
 reaching a constant weight. The dried samples were then ground into a fine
 powder using an agate mortar grinder (RM200, Retsch, Haan, Germany) and a
 ball mill (MM400 Ball Mill, Retsch) for nutrient measurements.
   <strong>2.4 Nutrient
 measurements</strong> The concentrations of six
 nutrients were analyzed in both leaf and root organs: nitrogen (N),
 phosphorus (P), sulfur (S), potassium (K), calcium (Ca), and magnesium
 (Mg). Nitrogen concentrations were measured using an elemental analyzer
 (Vario Max CN Element Analyzer, Elementar, Hanau, Germany). For the other
 nutrients, leaf and root samples were acidified with 68% nitric acid
 (HNO<sub>3</sub>) and digested using a microwave digestion
 system (Mars X Press Microwave Digestion System; CEM, Matthews, NC, USA).
 The acid solutions were heated to volatilize HNO<sub>3</sub>,
 reducing their acidity, and then diluted with ultrapure water to a final
 volume of 15 ml. Nutrient concentrations in the solutions were measured
 using an inductively coupled plasma-optical emission spectrometer
 (ICP-OES, Optima 5300 DV; PerkinElmer, Waltham, MA, USA). The nutrient
 concentrations of leaves and roots were then calculated based on the
 nutrient concentrations in the solutions and the dry weight of the samples
 used for digestion (Liu et al., 2024, Zhang et al., 2022).
description: # Phylogeny overrides environmental effects in explaining leaf and root
 nutrient concentrations in Fabaceae Dataset DOI:
 [10.5061/dryad.sxksn03fs](10.5061/dryad.sxksn03fs) ### Files and variables
 #### File: nutritions_environment.csv；species_name.csv **Description:** We
 measured the concentrations of six essential nutrients (N, P, S, K, Ca,
 and Mg) in both the leaves and roots of 121 Fabaceae species collected
 across diverse vegetation types in China. These measurements aimed to
 investigate nutrient allocation patterns between above--- and belowground
 organs and to assess the roles of phylogeny and environment in shaping
 nutrient variation. ##### Variables * Six essential nutrients (N, P, S, K,
 Ca, and Mg) in both the leaves and roots of 121 Fabaceae species * Soil
 and climate variable **Abbreviations** * Leaf and root element
 concentrations **N_leaf** — Leaf nitrogen concentration, mg kg⁻¹ (dry
 mass) **P_leaf** — Leaf phosphorus concentration, mg kg⁻¹ (dry mass)
 **S_leaf** — Leaf sulfur concentration, mg kg⁻¹ (dry mass) **K_leaf** —
 Leaf potassium concentration, mg kg⁻¹ (dry mass) **Ca_leaf** — Leaf
 calcium concentration, mg kg⁻¹ (dry mass) **Mg_leaf** — Leaf magnesium
 concentration, mg kg⁻¹ (dry mass) **N_root** — Root nitrogen
 concentration, mg kg⁻¹ (dry mass) **P_root** — Root phosphorus
 concentration, mg kg⁻¹ (dry mass) **S_root** — Root sulfur concentration,
 mg kg⁻¹ (dry mass) **K_root** — Root potassium concentration, mg kg⁻¹ (dry
 mass) **Ca_root** — Root calcium concentration, mg kg⁻¹ (dry mass)
 **Mg_root** — Root magnesium concentration, mg kg⁻¹ (dry mass) **Climatic
 variables** * **MAT** — Mean annual temperature, °C * **MAP** — Mean
 annual precipitation, mm * **TS** — Temperature seasonality, standard
 deviation × 100 (WorldClim units) * **PS** — Precipitation seasonality,
 coefficient of variation % (WorldClim units) **Soil variables** * **BD** —
 Soil bulk density, g cm⁻³ * **Clay** — Clay content, % (by mass) *
 **Silt** — Silt content, % (by mass) * **Sand** — Sand content, % (by
 mass) * **CEC** — Cation exchange capacity, cmol kg⁻¹ * **pH** — Soil pH
 (unitless) * **SOC** — Soil organic carbon, g kg⁻¹ ## Code/software The
 data are provided as Microsoft Excel (.xlsx) files, which can be opened
 using Microsoft Excel (any version) ## Access information Other publicly
 accessible locations of the data: * No