This data set provides net primary productivity (NPP) estimates and associated field measurements for six sites located along the 250-km, west-east transect of the Oregon Transect Ecosystem Research Project (OTTER) in the Pacific Northwest.

Leaf area indices, biomass, and NPP vary about 10-fold across the OTTER transect. Leaf area index (LAI) ranges from 0.4 m2/m2 at the Juniper/Sisters site to 8.6 m2/m2 at the Scio western Cascade site. Total NPP follows a similar trend with the Juniper/Sisters site having the lowest NPP value (300 g/m2/yr) and the Scio site having the highest (2,250-2,570 g/m2/yr). Total tree biomass across the transect ranges from to 1,080 g/m2 at Juniper/Sisters to 71,080 g/m2 at Cascade Head. Vegetation intercepts 22% to 99.5% of incident photosynthetically active radiation along the transect.

There is one data file (.csv format) with this data set.

Revision Notes: Only the documentation for this data set has been modified. The data files have been checked for accuracy and are identical to those originally published in 1999.