Seed bank community and soil texture relationships in a cold desert

Sustainable dryland management depends on understanding environmental factors driving the composition of current and future ecological communities. While there has been extensive research on aboveground plant communities, less is known about belowground soil seed bank communities. In the Colorado Plateau of the western United States, we simultaneously explored aboveground and belowground plant communities and how they varied across sites with similar climate but contrasting soil textures. We found that aboveground vegetation and belowground seed bank community composition each varied significantly among sites. We also observed marked aboveground-belowground compositional dissimilarity across sites, suggesting that the two spatially-associated communities may respond differently to the same environmental gradient. Lastly, we found that abundances of cheatgrass (Bromus tectorum) – one of the region's major exotic invasive plants – varied strongly with soil texture, a finding with implications for invasive species management. From our results, we highlight two general patterns for dryland managers. First, we show that aboveground and belowground plant communities can respond to the same environmental variation in a strongly divergent manner. Second, the data underscore a large potential role for soil texture and its associated factors in mediating plant community responses to a range of environmental conditions.