Figure 6: Relationship between P and R.

Relationship between integrated rates of photosynthesis (P) and respiration (R) in the NAST (filled squares) and SATL (open squares). The blue line is the regression line for the NAST data: R=0.76P+28.25, R2=0.59, n=47. The red line is the regression line for the SATL data: R=0.98P−8.56; R2=0.64; n=46. Both the slope and intercept of the two equations are significantly different (t-test (n=89)=12.89, P=0.0001; t-test (n=89)=22.28, P=0.0001, respectively). The dotted line indicates the 1:1 line.