Combining USGS science with NASA expertise in Earth observations, software engineering, and high performance computing, the team developed an Invasive Species Forecasting System (or ISFS), that can produce habitat suitability and distribution prediction maps for tamarisk in the continental United States.

"This partnership will have a lasting effect in bringing our best science to the urgent challenges of invasive plants, animals, and diseases," said Mark Limbaugh, Interior's Assistant Secretary for Water and Science. "Tamarisk is one of the most harmful invasives in the country, particularly in the Southwest, and we need to work regionally and strategically in our efforts to control it."

The ISFS is an outgrowth of Team Tamarisk, a Cooperative Conservation initiative that brought together hundreds of land managers and scientists in the spring of 2004 to work with Southwestern communities on a collaborative approach to tamarisk control. Co-sponsored by Interior and other members of the President's National Invasive Species Council, the Albuquerque conference pinpointed research gaps and the need for more effective mapping of invasives.

The ISFS application, which is used at the USGS National Institute of Invasive Species Science in Fort Collins, Colo., was successfully tested when the pink-flowered tamarisk bloomed last summer in Colorado.

"The ISFS combines NASA satellite data with tens of thousands of field sampling measurements, which are then used to analyze past and present distributions of non-native plants and predict their future growth patterns," said Tom Stohlgren, National Institute director. Land managers and others can use the ISFS to generate color-coded maps to help predict and manage the spread of troublesome invasive species.

"Integrating innovative Earth observation technology enables the USGS to significantly enhance its ability to support invasive species management," said Ed Sheffner, program manager for invasive species in the Applied Science Program at NASA Headquarters in Washington.

Because the tamarisk's long roots tap into underground aquifers, its groundwater -absorbing qualities may add to the severity of the drought in the western states. Tamarisk also increases the salt concentration of the soil and degrades habitats for native species along river systems. The infestation causes severe ecological and economic problems, costing the region hundreds of millions of dollars a year in economic activity.

A large shrub to small tree native to Africa and Eurasia, tamarisk was introduced to the western United States in the early 1800s as ornamental vegetation and for wind and erosion control. It has since spread and can be found in the West from Minnesota to California and from Mexico to Canada.

The ISFS uses observations and products from NASA's Terra, Aqua, and Earth Observing-1 satellites and the USGS-operated Landsat satellites, together with field data from government and non-government contributors. The satellites observe and measure sunlight reflected by plants and their environments. The satellites "lock in" on unique aspects of the reflected light to determine tamarisk's current locations and habitats vulnerable to invasion.

During the plant's blooming season, ISFS-generated maps predicting tamarisk locations matched observations of it in the field. These predictive maps are an important new tool for land managers involved with tamarisk-related control and restoration efforts.

"Satellite data coupled with computer modeling helps us understand where tamarisk is likely to be growing, even in remote locations that field researchers cannot easily reach," said John Schnase, principal investigator of the ISFS project at NASA's Goddard Space Flight Center in Greenbelt, Md.

The ISFS uses invasive species occurrence and abundance data from the Global Organism Detection and Monitoring System developed by the USGS Fort Collins Science Center and Colorado State University. This monitoring system is an on-line database that allows people to report sightings of tamarisk or other invasive species to USGS scientists, who then confirm the observations and incorporate the new data into ISFS map products. The USGS also uses the ISFS to predict the distribution of other invasive species, such as cheatgrass and Canadian star thistle, and aquatic species.

More information is at http://biology.usgs.gov/invasive/ and http://www.niiss.org. The attached pdf contains a description of the ISFS tamarisk application published this month in the journal Frontiers in Ecology and the Environment.