Assessing Tamarisk invasion risk with Landsat 8 at Havasu National Wildlife Refuge

EarthzineDEVELOP Fall 2014 VPS, DEVELOP Virtual Poster Session, Original

Project Team: Arizona Ecological Forecasting Team

Team Location: USGS-Colorado State University, Fort Collins, Colorado

Tama'Risk' mapping in Havasu National Wildlife Refuge using NASA's Earth Observing System. Image Credit: Arizona Ecological Forecasting Team

Tama’Risk’ mapping in Havasu National Wildlife Refuge using NASA’s Earth Observing System. Image Credit: Arizona Ecological Forecasting Team.

Authors:

Amanda West

Stephen Chignell

Matthew Luizza

Peter Gibbons

Brian Woodward

Mentors/Advisors:

Dr. Paul Evangelista (Natural Resource Ecology Lab, Colorado State University)

Dr. Catherine Jarnevich (USGS Fort Collins Science Center)

Nicholas Young (Natural Resource Ecology Lab, Colorado State University)

Past/Other Contributors:

Dr. Leanne Hanson (USGS Fort Collins Science Center)

Dr. Chris Holmquist-Johnson (USGS Fort Collins Science Center)

Dr. Joan Daniels (USGS)

Linda Miller (Havasu National Wildlife Refuge)

Abstract:

Tamarisk (Tamarix spp.) is a tree genus introduced into the U.S. in the late 1800s from Eurasia. Since that time, it has become a problematic invader, spreading over 3.3 million acres in the western U.S., where it is a critical concern to water resources. This project utilized NASA’s Earth Observing System (EOS) data and species distribution modeling to map the current extent of tamarisk in the Topock Marsh of Havasu National Wildlife Refuge, Arizona.åÊ Located in southern Arizona, Topock Marsh is considered the ‰ÛÏcrown jewel of the Lower Colorado River.‰Û The 4,000-acre marsh provides a range of ecosystem services to the Colorado River Basin, including critical habitat for the southwestern willow flycatcher (Empidonax traillii extimus) and the Yuma clapper rail (Rallus longirostris yumanensis), two federally listed endangered bird species. Dense tamarisk stands on stream banks accumulate sediment in their extensive roots, narrowing stream channels and increasing flooding potential, which alters critical habitat for fish such as the humpback chub (Gila cypha). Additionally, tamarisk competes with native vegetation for above- and below- ground resources and may increase fire frequency and intensity, thus making detection and mitigation of this problematic invasive species a high priority for land managers. The NASA DEVELOP Arizona Ecological Forecasting team used biologically meaningful indices derived from moderate spatial resolution (30 meter) Landsat 8 data and a digital elevation model from the Shuttle Radar Topography Mission to assist in modeling the current extent of tamarisk invasion around Topock Marsh. No such assessment had been conducted to date. Integrating NASA Earth observations with field collected occurrence data and ancillary geospatial datasets provided a time- and cost-effective strategy for land managers to conduct subsequent monitoring and mitigation efforts, and will play an important role in the Havasu National Wildlife Refuge Comprehensive Conservation Plan.

 

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