Physiological dataset of Calamagrostis angustifolia under 14 years of nitrogen addition treatment

During the measurements, the photosynthetically active radiation (PAR) was strictly controlled at 1500 μmol·m⁻²·s⁻¹, the ambient CO₂ concentration was maintained at 420 μmol·mol⁻¹, and the leaf temperature was stabilized at 28.0±0.1 °C. Leaf area was measured using an LI-3000c portable leaf area meter, and leaf fresh weight and oven-dried dry weight were weighed using an electronic balance with a precision of 0.0001 g.

Regarding ecological stoichiometric characteristics, leaf carbon and nitrogen contents were determined using a Vario Max Cube elemental analyzer, while leaf phosphorus content was determined using sulfuric acid-hydrogen peroxide digestion followed by molybdenum-antimony anti-spectrophotometry. Derived functional traits (such as water use efficiency, stomatal limitation value, specific leaf area, and photosynthetic nitrogen use efficiency), as well as the phenotypic plasticity index (PPI) and phenotypic integration (PI), were all calculated based on the measured basic data.This dataset is presented as a general tabular file.

The data table contains systematic observation records from 45 quadrats. The row labels represent different sample IDs and their corresponding spatial plots and nitrogen treatment groups. The column labels include 14 leaf functional trait indicators and integration indices, with their corresponding units as follows: net photosynthetic rate (μmol·m⁻²·s⁻¹), stomatal conductance (mol·m⁻²·s⁻¹), transpiration rate (mmol·m⁻²·s⁻¹), intercellular CO₂ concentration (μmol·mol⁻¹), water use efficiency (μmol·mmol⁻¹), stomatal limitation value (dimensionless), carbon content (mg·g⁻¹), nitrogen content (mg·g⁻¹), phosphorus content (mg·g⁻¹), C:N ratio, C:P ratio, N:P ratio, specific leaf area (cm²·g⁻¹), leaf area (cm²), leaf dry mass (g), leaf dry matter content (%), and photosynthetic nitrogen use efficiency (μmol·g⁻¹·s⁻¹).