Table 1.

Values used in SPA for this study

Parameter/Variable	Symbol	Units	Value	Source
Ambient atmospheric CO2 concentration	Ca	mmol mol−1	374	Value from recent past
Canopy layer capacitance	Cn		2000	Williams et al. 35
Canopy hydraulic conductivity	Gp	mmol m−1 sec−1 MPa−1	3.5	Zeppel et al. 40
Layer height of soil	H	m	0.1–1.0 m depth, then 0.2–3.4 m	Site estimate
Leaf area index	LAI	m−2 m2	0.1–2.3	MODIS LAI product
Areal concentration of leaf N	N	g m−2 ground area	0.16–3.65	Prior et al. 111 and Ghannoum et al. 109
Proportion of total canopy N in top layer	Ntop		0.125	Zeppel et al. 40
Fine root radius	rr	M	0.0001	Zeppel et al. 40
Air temperature	Ta	°C	Variable	Zeppel et al. 40
Leaf temperature	Ti	°C	Variable	Zeppel et al. 40 and varied in scenarios
RuBP carboxylation capacity	Vcmax	μmol g−1 sec−1	27.4074	Zeppel et al. 40
Maximum electron transport rate	Jmax	μmol g−1 sec−1	48.1481	Zeppel et al. 40
δA/δgs threshold for stomatal opening	Ι	%	1.0007	Williams et al. 35
Minimum sustainable leaf water potential	Ψlmin	MPa	−2.5	Kelley et al. 110
Soil water potential	Ψs	MPa	−0.5	Predawn leaf water potential, estimated
% soil clay content in top 10 cm		%	15.0	Zeppel et al. 40
% soil sand content in top 10 cm		%	85.0	Zeppel et al. 40
Drain check – field capacity as fraction of total porosity		Fraction	0.5	Zeppel et al. 40
Latitude		°	33° 39′ 42″
Dimension of leaves		m2	0.08	Prior et al. 51
Root resistivity		MPa sec g mmol−1	100	Estimated
Root biomass		g	2450	Chen et al. 108
Rooting depth		m	3.4	Chen et al. 108

SPA model input values indicating the name, symbol, units, value used, and whether the data were measured or estimated for the study site.