Herbarium infrastructure development and ecological applications of specimens using geographic information systems

Geographic Information Systems (GIS) allow for herbarium data to be used for new scientific research and also for the greater efficiency of the traditional uses of herbaria. My research uses the resources of both the herbarium at the University of Tennessee at Chattanooga (UCHT) and partnering herbaria of the Southeastern Regional Network of Expertise and Collections (SERNEC) to examine methods of incorporating new GIS technology into a functional infrastructure in order to enhance botanical research. Evaluations were performed on database and georeferencing software for use in the development of a pilot, GIS-enabled website used to query herbaria specimen information. Using this newly created database infrastructure, two ecological studies were performed using improved SERNEC datasets. In the first study, three common wetland invasive plant species were chosen and analyzed via two different methods to determine the historic rate and pattern of spread as well as to identify periods of invasiveness. Performance of these methods varied in scale with a general, area-corrected approach covering the entire southeastern United States and an associate species-corrected method covering smaller, regional areas of dense historical specimen collection. Results showed positive spread over time for these three species across both methods; however, periods of invasiveness did not coincide between the two methods. The use of two different methods and the subsequent comparison of results show the importance of sampling bias correction, scale selection, and adequate sample sizes for spatiotemporal analyses of plant distributions using herbarium records. The second study describes the spread of Baccharis halimifolia L. into new physiographic areas of the vi southeast using SERNEC records in GIS. Results were compared against distribution descriptions in the taxonomic literature. The dataset strongly complimented the existing distributions described in the taxonomic literature and, therefore, supports the concept that recent range expansion into previously unoccupied physiographic areas has truly occurred for this species, rather than being an artifact of collection bias. The two studies mentioned above have been submitted for publication in peer-reviewed, scientific journals and are arguments for the use of herbarium data within GIS software. It is of note that similar techniques will be fundamental to future botanical research in the southeast.