The Art and Science of Weed Mapping

Authors

David T. Barnett, Colorado State University - Fort Collins
Thomas J. Stohlgren, National Institute of Invasive Species Science, Fort Collins Science Center
Catherine S. Jarnevich, National Institute of Invasive Species Science, Fort Collins Science Center
Geneva W. Chong, Northern Rocky Mountain Science Center, US Geological Survey
Jenny A. Ericson, National Invasive Species Program, National Wildlife Refuge System
Tracy R. Davern, National Institute of Invasive Species Science, Fort Collins Science Center
Sara E. Simonson, Colorado State University - Fort Collins

Date of this Version

2-6-2007

Comments

Published in Environ Monit Assess 132:235–252 (2007).

Abstract

Land managers need cost-effective and informative tools for non-native plant species management. Many local, state, and federal agencies adopted mapping systems designed to collect comparable data for the early detection and monitoring of non-native species. We compared mapping information to statistically rigorous, plot-based methods to better understand the benefits and compatibility of the two techniques. Mapping non-native species locations provided a species list, associated species distributions, and infested area for subjectively selected survey sites. The value of this information may be compromised by crude estimates of cover and incomplete or biased estimations of species distributions. Incorporating plot-based assessments guided by a stratified-random sample design provided a less biased description of non-native species distributions and increased the comparability of data over time and across regions for the inventory, monitoring, and management of non-native and native plant species.