Buffelgrass (Pennisetum ciliare) invasion is associated with reduced plant diversity and changes in carbon storage in the Sonoran Desert
| Authors: | R. Chelsea Nagy, Emily Fusco, Adam L. Mahood, Dylan P. Murphy, Jennifer K. Balch, Kimberly Franklin, Bethany A. Bradley |
| Year: | 2026 |
| Type: | Scientific Journal |
| Station: | Pacific Northwest Research Station |
| DOI: | https://doi.org/10.1016/j.jaridenv.2026.105680 |
| Source: | Journal of Arid Environments |
Abstract
Buffelgrass (Pennisetum ciliare) is a perennial bunchgrass, invasive in arid ecosystems of the United States, Australia, and Mexico. Buffelgrass invasion detrimentally affects ecosystems, but it is unclear how the amount of invasion affects ecological impact. Here, we investigated how buffelgrass abundance affects: plant diversity, aboveground biomass carbon, and surface soil (0-10 cm) carbon. We established 13 plots in unburned areas, across a range of buffelgrass cover (0-68%) in the Sonoran Desert of Arizona, USA. Shannon diversity decreased significantly with buffelgrass cover. Herbaceous carbon storage significantly increased with buffelgrass cover. There was a significant non-linear relationship between woody carbon storage and buffelgrass cover and positive associations in occurrence between buffelgrass and many woody plant species. This may indicate facilitation of buffelgrass establishment by woody plants, or that buffelgrass does not competitively exclude shrubs and cacti until high cover is reached, or following fire. Total soil carbon in surface soils was significantly lower under buffelgrass and bare ground compared to native vegetation, though did not vary significantly across the buffelgrass gradient, in the absence of fire. Because diversity metrics had linear negative associations with buffelgrass cover, management strategies that reduce buffelgrass cover may still have positive ecological outcomes even without eradication.