Assessing Exotic Plant Distribution, Abundance, and Impact at Montezuma Castle and Tuzigoot National Monuments in Arizona

Abstract

Exotic plants are invading federal lands at an estimated rate of 1,862 ha each day, reducing the natural diversity many of these places were set aside to protect. Effective invasive species management must be based on thorough knowledge of these species’ locations and distributions, modes and rates of spread, potential and known effects, and control methods. We mapped the location and distribution of 50 exotic plant species in two Arizona national monuments using state-of-the-art GIS and GPS technologies. The Alien Plants Ranking System was used to prioritize species for management and develop an exotic plant management plan for the park units. Other project goals included testing the efficacy of roaming surveys for exotic plant mapping using standards suggested by the North American Weed Management Association and creating a basis for future monitoring of weed populations. Mapping weeds digitally offers many advantages including increased speed and accuracy, enhanced data sharing capabilities, and easy updates, all of which aid in establishing management priorities and providing a baseline for future monitoring efforts.