Table 2.

Parameter values used in Equation 1

Regression coefficient (and units)	Broadleaf trees (BT)	Needleleaf trees (NT)	Shrubs (S)	C3 grasses	C4 grasses
r 0 (μmol CO2 m−2 s−1)	1.7560 ± 0.2180	1.4995 ± 0.1793	2.0749 ± 0.0774	2.1956 ± 0.1408	n/a
r 1 (μmol CO2 m−2 s−1 (gN (m2 leaf)−1) −1)	0.2061 ± 0.0023	0.2061 ± 0.0023	0.2061 ± 0.0023	0.2061 ± 0.0023	n/a
r 2 (μmol CO2 m−2 s−1 (oC) −1)	0.0402 ± 0.0096	0.0402 ± 0.0096	0.0402 ± 0.0096	0.0402 ± 0.0096	n/a
n l0 (kg N (kg C)−1)	0.0369	0.0235	0.0349	0.0480	0.0238
${\sigma }_{\mathrm{l}}$ (kg C (m2 leaf)−1)	0.0506	0.112	0.0512	0.0248	0.0656
n l,a (gN (m2 leaf)−1) from n l,0 x ${\sigma }_{\mathrm{l}}$ × 103	1.867	2.632	1.787	1.190	n/a
R d,25 with T G = 25 oC (μmol CO2 m−2 s−1)	1.136	1.037	1.438	1.436	n/a

Parameters r ₀, r ₁ and r ₂, which define R _d,25 ⁵ and for each plant functional type (PFT). Intermediate rows provide values for calculation of n _l,a. Values of nitrogen content prescribed to Joint UK Land Environmental Simulator (JULES) (n _l0) and specific leaf density (σ _l), used to calculate nitrogen content in area-based units, as n _l,a, are the 50-percentiles across the TRY database for the PFTs. The last row shows values of R _d,25 calculated using Eq. (1), assuming T _l = T _G = 25 °C. The GlobResp database contains global patterns in upper canopy leaf-level respiration, R _d, of BTs, NTs, Ss and C₃ grasses. Comparable data for C₄ grasses remains lacking (n/a), and hence standard JULES values for R _d are used. Uncertainty bounds are ± one standard errors