Experiment Title:

Re-examining coordination between root and leaf economics for a general plant trait space: a case study in Fujian, China

 Institutions responsible:

Tsinghua University
Experiment Description:
  1. The dimensions of plant functional traits: how many dimensions exist among multiple plant functional traits? Do traits of leaves, stems and roots coordinate with each other? If yes, what are the coordination patterns? Can we predict those patterns?
  2. The diversity of plant functional traits: How does the within-site trait variation differ among different functional traits and shift among sites? how to explain the within-site distribution of plant functional trait? How does this distribution vary along environmental gradient? Can we predict the within-site distribution and its variation among sites?
Variables being tested: Experimental Details (factorial design, replication, lab/field/ controls, vegetation type): Data availability: Study limitations:
Hydraulic traits:

vH: Huber value (cm2/cm2)

SWCleaf: Leaf saturated water content (g/g)

SWCbranch: Branch saturated water content (g/g)

WD: Sapwood density (g/cm3)

Ks: Xylem hydraulic conductivity (kg m-1 s-1 MPa-1)

TLP: Turgor loss point (Mpa)

H: Tree height (m)

DBH: Tree diameter at breast height (cm)

Fine root traits:

  • RDMC: Root dry matter content (g/g)
  • RD: Mean root diameter (mm)
  • SRL: Specific root length (m/g)
  • RTD: Root tissue density (g/cm3)
  • SRA: Specific root area (cm2/g)
  • SRR25: Specific root respiration at 25℃ (nmol/g/s)
  • RNC: Root nitrogen content (%)
  • RCC: Root carbon content (%)
  • RPC: Root phosphorus content (%)

Leaf traits:

  • SLA (1/LMA): Specific leaf area (cm2/g)
  • Rdark25: leaf dark respiration rate at 25℃ (umol/m2/s)
  • Rlight25: leaf light respiration rate at 25℃ (umol/m2/s)
  • Vcmax25: Maximum rate of Rubisco activity at 25℃ (umol/m2/s)
  • Asat: Light saturated net photosynthetic rate (umol/m2/s)
  • LNC: Leaf nitrogen content (%)
  • LCC: Leaf carbon content (%)
  • LPC: Leaf phosphorus content (%)

Stem/trunk traits:

  • rs25： mass-based stem respiration at 25 ℃ (nmol/g/s)
 The experiment design involves two sampling sites. One is located at the top of a mountain (the Hilltop site); another is located at the valley between two mountains (the Valley site). The vegetation type on the sites are subtropical evergreen broad-leaved forest.

The experiment sampled a total of 26 species on the Hilltop site, among which there were 13 trees, 11 shrubs and 2 lianas. For the Valley site, the experiment sampled a total of 25 species, among which there are 13 trees, 10 shrubs and 2 lianas.

To maintain maximum comparability, we sampled leaf, stem and fine root samples from the same plant. This minimizes bias caused by batch effect, and is believed to provide a more accurate result than species-averaged traits using global public data.

In terms of replication, we sampled 3 individuals for each species on hydraulic and leaf traits, and sampled 1 individual for each species on stem and fine root traits.

 The data is expected to be publicly available and will be uploaded with publication.

All trait measurements were conducted between June 19th to 28th in 2024, at Shanghang county, Longyan district, Fujian province, P.R. China (25.093595, 116.648637), with two sites that are relatively close to each other (the Hilltop site, the Valley site).

Trait data measurement originated from this experiment was integrated into a .csv format table for further use.

 Replicates in fine root trait measurement: because of sampling workload and the limited amount of field work time, we only sampled one individual

Trait measurement in different sites: this experiment used two sites (the Hilltop site, the Valley site) to compare the difference between traits of plants in distinct water and light availability. Nevertheless, to effectively represent the climatic and hydrologic condition in the sampling location, more sites representing elevation gradient are needed.