Riparian Plant Community Response to Fire in the Middle Rio Grande
 
Lauren Bansbach1*, Kelly Steinberg1,2
 
1University of New Mexico, Albuquerque, NM, USA; LBansbach@unm.edu
2Bosque Ecosystem Monitoring Program, Bosque School, Albuquerque, NM, USA; ksteinberg@unm.edu
 
 
Fire in riparian ecosystems can alter the structure and composition of woody vegetation, but the effect of fire on the full riparian plant community (i.e. including herbaceous vegetation) is not well understood. Using long-term plant cover data collected by the Bosque Ecosystem Monitoring Program (BEMP), I characterized changes in the riparian plant community at two sites along the Rio Grande in central New Mexico. One site burned in 2003 and has been monitored from 2003-2015, and the adjacent unburned site serving as the pre-fire control has been monitored from 2000-2015. My research questions were: (1) Does the riparian plant community recover to pre-fire composition in subsequent years after a burn?; (2) Does the relative proportion of exotics and/or annuals change in subsequent years after a burn? To answer these questions, I compared species diversity between the two sites and used non-metric multidimensional scaling (NMDS) analysis to compare changes in species composition through time. Preliminary results show that species diversity at the burned site steadily approaches diversity of the unburned site in the years following the fire. However, NMDS analysis suggests that the plant community composition remains consistently different between the two sites. These differences may be driven by exotic annuals like Bassia scoparia, which shows similar magnitudes of year-to-year change at each site, but total cover is consistently higher at the burned site. Results from this study provide a novel investigation into the long-term consequences of fire for an arid riparian plant community. Given the significance of riparian habitats and the likely increase of riparian fires under climate change, it is critical to understand how the riparian plant community responds to fire disturbance.