Southern Arizona Ecological Forecasting
Detecting and Monitoring Invasive Buffelgrass in the National Parks of Southwestern Arizona
Organ Pipe Cactus National Monument, located in southern Arizona, is home to both diverse native species and a rich cultural history. It is the only place in the United States where large stands of organ pipe cactus (Stenocereus thurberi) can be found. Unfortunately, the Park's landscape is under threat from invasive buffelgrass (Pennisetum ciliare), a non-native species originally brought to the United States from Eurasia and Africa to stabilize soils and improve the productivity of rangelands. Buffelgrass forms dense mats in vacant gaps between native plants that normally serve as fire breaks. Consequentially, these mats become vast fuel loads with high peak fire temperatures that drastically increase the chance of devastating wildfires. The plant also threatens the transformation of native desertscapes to grasslands through an expansive root system that allows the species to outcompete native flora. Currently, park managers rely on costly aerial and ground surveys to monitor this species. To improve the capability of the National Park Service (NPS) to combat the spread of buffelgrass, this project investigated and furthered two methodologies for buffelgrass detection, and mapped predicted locations of buffelgrass presence. Because buffelgrass has a quick phenological response to precipitation events, the Climate-Landscape Response (CLaRe) model was used to study the relationship between remotely sensed Normalized Difference Vegetation Index (NDVI) data derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) and rainfall data from the Parameter-elevation Relationships of Independent Slopes Model (PRISM). The team also tested a spectral-based approach, using the Mixture Tuned Matched Filtering (MTMF) technique on high-spatial-resolution WorldView-2 data.
Project Video:
Buffelgrass: The Grass that Won't Quit!
- Location
- NASA Jet Propulsion Laboratory
- Term
- Fall 2016
- Partner(s)
- National Park Service, Saguaro National Park Rincon Mountain District
USGS Southwest Biological Science Center
USGS Southwest Biological Science Center
Northern Arizona University (NAU) - NASA Earth Observations
- Terra, MODIS
WorldView-2 - Team
- Molly Spater (Project Lead)
Nick Rousseau
Erika Higa
Natalie Queally - Advisor(s)
- Natasha Stavros (NASA Jet Propulsion Laboratory)