Long-Term Vegetation Trends on the Idaho National Laboratory
Investigators and Affiliations
Amy D. Forman, Plant Ecologist, Environmental Surveillance,
Education and Research Program, S.M. Stoller Corporation, Idaho
Roger D. Blew, Ecologist, Environmental Surveillance, Education and
Research Program, S.M. Stoller Corporation, Idaho Falls, ID
Jackie R. Hafla, Natural Resources Scientist, Environmental
Surveillance, Education and Research Program, S.M. Stoller
Corporation, Idaho Falls, ID
U.S. Department of Energy Idaho Operations Office
In 1950 at the request of the Division of Biology and Medicine of
the Atomic Energy Commission requested a background survey for
naturally occurring radioactive materials in the vicinity of what is
now known at the INL. One of the legacies of that background survey
in 1950 remains today in the form of the Long-Term Vegetation (LTV)
plots. The LTV plots originally consisted of 110 plots on and near
the INL. Over the years some of the plots have been lost due to
agricultural and other development activities and 92 plots remain.
These plots were surveyed in 1950, 1957, 1965, 1975, 1985, 1995 and
2001. A subset of 35 or 36 plots were also surveyed in 1978, 1983,
The plots originally consisted of two transects 50 ft (15.24 m) in
length. Vegetative cover of shrub crown and grass basal area was
measured using line intercept and density was measured in quadrats
placed at intervals of 5 ft (1.52 m) along the two transects. In
1985, a third transect 65.6 ft (20 m) in length was added to each
plot to support measurement of cover using point interception. Also,
a photographic record of each plot has been made during each survey
beginning in 1957.
Although the original intent of the LTV plots were to provide
information on presence of naturally occurring radioactive materials
in the environment, the data from these plots have also been used to
assess the potential impact of nuclear energy research and
development and other activities on ecological resources native to
the INL. The LTV plots have provided important background
information for assessing potential impact to ecological resources
in numerous Environmental Assessments and Environmental Impact
Statements at the INL.
Also, the LTV data have become an invaluable resource for research
on the structure and function of native sagebrush steppe vegetation
communities. The INL LTV plots represent one of the most intensive
(in terms of the amount and kinds of data available for each plot)
and one of the most extensive (in terms of its geographical and
temporal extents) datasets for the sagebrush steppe ecosystem type.
The significance of this dataset to the broader scientific and
natural resource management communities is further amplified when
considering that it represents the largest remnant of good condition
sagebrush steppe. This significance is illustrated by the paper by
Anderson and Inouye (2001) that provided a summary of this dataset
through 1995. In the first five years following publication, this
paper was cited more than 40 times in the scientific literature.
There are three primary goals for current activities associated with
the LTV project. They include surveying plots in 2006, analyzing
data and preparing reports and manuscripts in 2007, and archive all
data collected since 1959 and incorporating that archive into the
Conservation Management Plan Ecological Data Management System.
Research objectives for this effort include investigating methods
for studying the population ecology of native bunchgrasses, the role
of annual forbs in the ecology of sagebrush steppe communities and
environmental controls on diversity of forbs.
Accomplishments through 2006
Data collection began in June 2006 and continued through July. We
surveyed all of the 92 remaining LTV plots. Field crews were trained
in late May and early June on survey methods and plant
identification. We conducted QA/QC audits on all data collected as
they were brought in from the field. There was a lag of no more than
one week between data collection and these audits.
Once the field data collection was completed, we began data
analysis. Because of the short amount of time between the completion
of data collection and the end of the fiscal year, data analysis in
2006 was limited to transforming the data so that it is in a format
consistent with the needs of the statistical analysis.
Because only limited data manipulation was completed in 2006, no
results are available to be reported here.
Plans for Continuation
In 2007 we plan to complete the data analysis and report
preparation. We also plan to begin work on at least two manuscripts
based on the results of the study. In 2007 and continuing into 2008,
we will begin the process of archiving the LTV data into the CMP
data management system. This will include converting all of the
photographic negatives into digital format.
Anderson, J., and R. Inouye. 2001. Landscape scale changes in
species abundance and biodiversity of a sagebrush steppe over 45
years. Ecological Monographs 71:531-556.