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Physical Sciences and Mathematics Commons™
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Full-Text Articles in Physical Sciences and Mathematics
Observer Bias In Anuran Call Surveys, Aaron Lotz, Craig R. Allen
Observer Bias In Anuran Call Surveys, Aaron Lotz, Craig R. Allen
United States Geological Survey: Staff Publications
Amphibian monitoring programs rarely question the quality of data obtained by observers and often ignore observer bias. In order to test for bias in amphibian call surveys, we sampled 29 clusters of wetlands from the Rainwater Basin, Nebraska, USA, totaling 228 functionally connected wetlands. Sampling consisted of 3-minute stops where volunteers recorded species heard and made digital recordings. Based on 627 samples, we examined 3 types of observer bias: omission, false inclusion (commission), and incorrect identification. Misidentification rates ranged from 4.2% to 18.3%. Relatively high and unquantified error rates can negatively affect the ability of monitoring programs to accurately detect …
The Art And Science Of Weed Mapping, David T. Barnett, Thomas J. Stohlgren, Catherine S. Jarnevich, Geneva W. Chong, Jenny A. Ericson, Tracy R. Davern, Sara E. Simonson
The Art And Science Of Weed Mapping, David T. Barnett, Thomas J. Stohlgren, Catherine S. Jarnevich, Geneva W. Chong, Jenny A. Ericson, Tracy R. Davern, Sara E. Simonson
United States Geological Survey: Staff Publications
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 …