The purpose of the Oregon Transect Ecosystem Research (OTTER) Project was to estimate major fluxes of carbon, nitrogen, and water in forest ecosystems using an ecosystem-process model driven by remotely sensed data. Study sites included a coastal forest of western hemlock, sitka spruce, and red alder in a recent clear-cut; a mid-elevation forest of mature Douglas fir in the lower Cascades and a fertilized plot nearby; and an inland forest of ponderosa pine on the drier eastern slope of the Cascades with a fertilized forest nearby. Meteorological data and remotely sensed measurements of foliar nitrogen and leaf area index drove the model, while field measurements of seasonal changes in canopy leaf area, photosynthetic capacity, stomatal conductance, foliage biochemistry, litterfall, and other components of plant production were used to validate the model. Each site was instrumented for continuous measurement of surface meteorology and monitored frequently for some aspects of carbon exchange, nutrient cycling rates, and water transport. The project was conducted from 1990 to 1991; the DAAC's data holdings include background data from 1989.
OTTER data sets include Canopy Chemistry, Meteorology, Field Sunphotometer, Airborne Sunphotometer, and Timber Measurements. They were transferred to the ORNL DAAC from the Ames Research Center node of the Pilot Land Data System (PLDS). Preceding info from http://daac.ornl.gov/OTTER/otter.html. Full details and access to other data from this project are available through the OTTER pages maintained by the ORNL DAAC. The OTTER NPP Data Set, described here, contains only the estimates of NPP and associated measurements from the OTTER transect that were made during the period 1989-1991. Preceding info from http://www-eosdis.ornl.gov/NPP/other_files/ott_des.html.