Figure 2. SEM for geographic variation of seed mass for black spruce, white spruce and jack pine.

Non-significant paths are indicated by dotted arrows. The thickness of the solid arrows reflects the magnitude of the standardized SEM coefficients. Standardized coefficients are listed beside each significant path, as is the variance explained (r²) for each endogenous variable. ¹AT, Annual temperature (°C); ²TS, Temperature seasonality (%); ³AP, Annual precipitation (mm); ⁴PS, Precipitation seasonality (°C); ⁵AR, Annual radiation (mrem); ⁶EF, Total potential evaporation in the fall (August to November) (mm); ⁷RG, Mean radiation in growing season (April to September) (mrem); ⁸EG, Total potential evaporation of growing season (April to September) (mm); ⁹TG, Mean temperature of growing season (April to September) (°C); ¹⁰TRG, Temperature range of growing season (°C).