Bee and Flowering Plant Communities in a Riparian Corridor of the Lower Rio Grande River (Texas, USA)

Abstract

5The Lower Rio Grande River (LRGR) in Texas is the physical boundary between the United 6 States and Mexico and is considered one of the world's most at-risk rivers due to intensified 7 management of the riparian corridor and human use. Exotic plant invasions have significantly 8 altered the native floral communities because of invasive giant reed, with potential impacts to the 9 native wildlife using resources in the riparian corridor. This study was conducted along a 3.22 10 km stretch of the LRGR in southwestern Webb County, TX to assess bee (Anthophila) 11 communities and their flowering-plant resources among proximal and distal terrestrial upland 12 and river-adjacent sub-corridors. Patterns related to the bee community across the two habitats 13 consisted of low variation and dominance by common taxa, suggesting the riparian corridor 14 could be used as a resource for bee foraging and soil-nesting. Although a lack of community 15 structure similarities among habitats were found, indicator species analysis produced two bee 16 genera that were more common and abundant in the upland habitat. Total number of individual 17 bees and genera collected across 26 dates and 2 years show a bimodal trend, with peaks in 18