Satellites spy invasion of grass
Scientists estimate that the invasive plant cheatgrass has infiltrated up to 100 million acres of land in the U.S. In order to determine its precise distribution and extent, satellite imagery is being employed by land managers working with easy to use softeware developed by the Pacific Northwest National Laboratory.
DB: This is Earth & Sky. Scientists at the Pacific Northwest National Laboratory in Washington are using NASA satellite images to track an invasion of cheatgrass.
JB: The cheatgrass plant originally came from Europe and Asia in the 1800s. Since then it’s become one of the most widespread weeds in the American west, covering an estimated 100 million acres.
DB: It “cheats” native grasses by maturing much earlier in the season, beating them to nutrients and water in the topsoil. What’s more, cheatgrass flowers and dies in the summer, providing fuel for wildfires. We spoke with national laboratory ecologist Janelle Downs.
Janelle Downs: Well I think that it’s clear in the last ten years that invasive species, in general, are probably one of the biggest threats to our nation’s ecosystems. Cheatgrass is just one of many invasive threats.
JB: In the past, researchers depended on aerial photographs and the reliable look from the window of a fast-moving pickup truck. But tools have been developed that make detailed images from satellites easily available for land managers to see the extent and distribution of cheatgrass.
Janelle Downs: Looking at the big picture that we get from imagery really emphasizes the fact that cheatgrass has taken over these large land areas.
DB: We have more at earthsky.org. Thanks today to NASA, explore, discover, understand. We’re Block and Byrd for Earth & Sky.
This link at the Pacific Northwest National Laboratory has more about the satellite imagery software for land managers tracking cheatgrass, including a phone number of who to call for the data.
Janelle Downs
Ecology
Scientist
Pacific Northwest National Laboratory
Richland, WA
Judith Graybeal
Pacific Northwest National Laboratory
Richland, WA
www.pnl.gov/news
Additional Teacher Resources
USDA: National Invasive Species Information Center
The National Invasive Species Information Center (NISIC) is a gateway to invasive species information; covering Federal, State, local, and international sources.
Ecological Society of America: Why are Invasive Species a Problem?
Invasive species may negatively impact native species in any number of ways, including eating them, competing with them, interbreeding with them, or introducing pathogens and parasites that sicken or kill them. Invasive species affect nearly all habitats on Earth, ranging from wilderness areas, to croplands, rangelands, and forests, as well as freshwater and marine ecosystems. Invasive species can be thought of as biological pollutants, with potentially severe impacts on the ecosystems they inhabit.
