OTTER Project/Campaign Document

Summary:

The Oregon Transect Ecosystem Research (OTTER) Project was an interdisciplinary project conducted from 1989 through 1991 as a cooperative effort between NASA and several universities in the United States and Canada to discern the ecology of western coniferous forests through the use of remote-sensing technology supported by ground observations. OTTER was designed to study the ability of remote sensing to detect biophysical characteristics of plant canopies. OTTER investigators tested a 1988 model that estimated the major fluxes of carbon, nitrogen, and water through a temperate coniferous forest ecosystem. Meteorological data and remotely sensed measurements of monthly changes in canopy leaf area, photosynthetic capacity, stomatal conductance, foliage biochemistry, litterfall, and other components of plant production were used to validate the model. OTTER combined laboratory studies with field work and remote-sensing techniques to help simulate and predict ecosystem processes.

OTTER was developed to discern the ecology of western coniferous forests through the use of remote-sensing technology supported by ground observations. It was an interdisciplinary project to test a model for estimating the major fluxes of carbon, nitrogen, and water through a temperate coniferous forest ecosystem and to study the ability of remote sensing to detect biophysical characteristics of plant canopies. OTTER investigators used a combination of remote-sensing techniques, field work, and laboratory study to simulate and predict ecosystem processes.

Project/Campaign Mission Objectives:

The goals of OTTER were

to simulate and predict ecosystem processes, such as photosynthesis, transpiration, aboveground production, nitrogen transformation, respiration, decomposition, and hydrologic processes;
to combine field, laboratory, and remote-sensing techniques to estimate key vegetation and environmental parameters;
to construct a geo-referenced database for extrapolating and testing principles, techniques, and prediction; and
to verify the predictions through direct measurements of process rates or controls on processes.

OTTER's main objective was to estimate major fluxes of carbon, nitrogen, and water in forest ecosystems through the use of an ecosystem-process model driven by remotely sensed data. Other objectives included the following: to simulate a forest ecosystem and predict a variety of parameters through the use of a computer model; to characterize the spectral variability in conifer foliage between age classes, species, and sites; and to characterize the stand mean and variability in the Leaf Area Index.

Discipline(s):

Earth Science

Geographic Region(s):

Western coniferous forest in Oregon, U.S.A.

Detailed Project/Campaign Description:

OTTER, a cooperative effort between NASA and several universities in the United States and Canada, was an interdisciplinary project designed to study the ability of remote sensing to detect the biophysical characteristics of plant canopies. Meteorological data and remotely sensed measurements of monthly changes in canopy leaf area, photosynthetic capacity, stomatal conductance, foliage biochemistry, litterfall, and other components of plant production were used to validate a computer model developed in 1988. Measurements were taken by remote-sensing instruments aboard satellites (NOAA-11); by instruments flown on NASA's ER-2, DC-8, and C-130 aircraft; from light aircraft; from light experimental (ultralight) aircraft; and on the ground.

The investigations were conducted in a 300-km transect of western coniferous forest in Oregon. Measurements were collected at six sites across an elevational and climatic gradient that stretched from the Pacific coast 300 km to the east. The first of the intensively studied sites, Site 1 (44° 03' N, 123° 57' 30" W ) Cascade Head, began at the Pacific coast and contained an alder stand. Site 2 ( 44° 36' N, 123° 16' W) was Warings Woods. Site 3, Scio (44° 40' 30" N, 123° 36' 40" W), was a dense Douglas fir forest. Site 4, Santiam Pass (44° 025' 20" N, 121° 50' 20" W), was a mountain hemlock/subalpine fir community. Site 5, Metolius [44° 25' N, 121° 40' W (control) and 44° 40' 30" N, 123° 36' 40" W (fertilized)], was a Ponderosa pine community. Site 6, Juniper (44° 17' 30" N, 121° 20' W ) was the site farthest east.

OTTER combined laboratory studies with field work and remote-sensing techniques to help simulate and predict ecosystem processes. Data collection began in the summer of 1989, and intensive field campaigns were conducted during 1990 and 1991. The field campaigns were coordinated with a Multi-sensor Airborne Campaign (MAC). The four 1990 data collection periods were timed to coincide with (1) pre-budbreak at the sites (late March to early April); (2) maximum understory leaf area index (LAI), minimum starch, maximum nitrogen, and maximum LAI in the overstory (late May to early June); (3) maximum LAI and water stress (mid-August); and (4) senescence of understory vegetation and reduced LAI and water stress (October). Additional data were gathered in May 1991. Airborne sun photometer data were also collected from 1990 through 1991 to provide quantitative atmospheric correction to remotely sensed data of forest reflectance and radiance.

2. Data Availability:

Data Type(s):: Imagery and tabular data.
Input/Output Media:: Selected data and imagery are available from the ORNL DAAC Web site (http://daac.ornl.gov). Data can be downloaded through FTP, and they are available on CD-ROM and on diskettes formatted for UNIX, PCs, and Macs.
Proprietary Status:: The data are free for public use.

3. Data Access:

Data Center Location:: The Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC) is housed within the Environmental Sciences Division at Oak Ridge National Laboratory, which is located in Oak Ridge, Tennessee, U.S.A.
Contact Information:: ORNL DAAC User Services Office
Oak Ridge National Laboratory
Telephone: +1 (865) 241-3952
Fax: +1 (865) 574-4665
E-mail: ornldaac@ornl.gov
Associated Costs:: The data are are available free of charge.

4. Principal Investigator Information: