The same data as in Fig 1 but averaged over 16 m intervals to represent a typical spatial resolution of aircraft or satellite sensors. Note that regression lines are quite similar to those for the 1 m data, suggesting that this analysis is also applicable to lower resolution data. The relationship between transect and leaf PRI can be significantly improved by estimation of PRI at full plant cover, thus eliminating the effect of the background. Each point represents means for a different species. For the transects, leaf photosynthesis was measured on Adenostoma for new burn and developing canopies and on Ceanothus for closed canopies.
Different points represent replicate transects and measurements at different times of year.
It is the only index which shows a significant relationship to leaf photosynthesis at the leaf level. It also shows less variation between stand ages at the transect level. WBI was correlated with leaf photosynthetic rate at both the canopy and transect levels but not at the leaf level. This relationship changed with canopy development for the transects. The highest canopy point represents Helianthus .