Skip to main content

Table 1 Summary of parameter settings used in the 3-PG simulations for ponderosa pine

From: Does overshoot in leaf development of ponderosa pine in wet years leads to bark beetle outbreaks on fine-textured soils in drier years?

3-PG Parameter Units Ponderosa pine
Biomass partitioning and turnover   
Allometric relationships & partitioning   
Foliage: stem partitioning ratio @ D = 2 cm 1.328
Foliage: stem partitioning ratio @ D = 20 cm 0.75
Constant in the stem mass v. diam. relationship 0.0046
Power in the stem mass v. diam. relationship 2.97
Maximum fraction of NPP to roots 0.8
Minimum fraction of NPP to roots 0.25
Litterfall & root turnover   
Maximum litterfall rate 1·month−1 0.021
Litterfall rate at t = 0 1·month−1 0.001
Age at which litterfall rate has median value months 36
Average monthly root turnover rate 1·month−1 0.015
NPP & conductance modifiers   
Temperature modifier (fT)   
Minimum temperature for growth °C −7
Optimum temperature for growth °C 18
Maximum temperature for growth °C 40
Frost modifier (fFRost)   
Days production lost per frost day Days 1
Soil water modifier (fSW)   
Moisture ratio deficit for f q = 0.5 0.7
Power of moisture ratio deficit 9
Canopy structure and processes   
Specific leaf area   
Specific leaf area at age 0 m2·kg−1 3.1
Specific leaf area for mature leaves m2·kg−1 3.1
Age at which specific leaf area = (SLA0 + SLA1)/2 Years 2.5
Light interception   
Extinction coefficient for absorption of PAR by canopy 0.5
Age at canopy cover Years 15
Maximum proportion of rainfall evaporated from canopy 0.1
LAI for maximum rainfall interception 5
Production and respiration   
Canopy photosynthetic capacity mol C·mol PAR−1 0.05
Ratio NPP/GPP 0.47
Minimum canopy conductance m·s−1 0
Maximum canopy conductance m·s−1 0.016
LAI for maximum canopy conductance 5
Defines stomatal response to VPD 1·mBar−1 0.05
Canopy boundary layer conductance m·s−1 0.14