Informing Future Decision Making on Uranium Mining in Arizona

Little Robinson Tank Life Cycle

Little Robinson Tank is an unmineralized reference and background site.

Vegetation surveys were conducted around four breccia pipe uranium deposits, which were in various stages of mine development, and at one non-mineralized reference area. Vegetation surrounding mines is one potential vector for wildlife and livestock exposure to radionuclides and inorganic constituents, via ingestion of potentially contaminated plant tissues.

It is unclear whether mining in the Grand Canyon watershed elevates concentrations of toxic elements in plant tissues or changes the plant community composition, especially downwind from the operational area. These data will be useful when characterizing chemical uptake in vegetation and for future exposure pathway studies at breccia pipe mine sites.

Objective

Collect species inventory, percent cover of plant species and ground surface categories, and distribution of gaps in perennial plant canopies information at each site.

Questions this study could help answer

Is the plant composition at sites characteristic of regional vegetation patterns, and is variation in species composition within sites attributable to underlying differences in native soil types?

Is there evidence that variation in vegetation composition around the breccia pipe deposits is attributable to mining activity?