Dormant seeds within the soil seed bank are an important component of plant communities that contribute to an area’s regeneration potential after disturbance. Uncovering relationships between environmental factors and seed bank characteristics can improve our understanding of how plant communities respond to disturbance and environmental change. We conducted field surveys and collected soil seed bank samples at 17 sites in sagebrush-steppe dominated areas of the Great Basin that varied in above-ground vegetation, fire history, and grazing use. We investigated whether shrub cover, ground cover, climate, or disturbance history were predictive of seed densities, diversity, presence of rare species, and similarity between above-ground and seed bank plant community composition. Fire frequency and a course measure of grazing use were not highly predictive of seed bank dynamics. Shrub cover predicted multiple seed bank characteristics: Rubber rabbitbrush (Ericameria nauseosa) was associated with increased densities of introduced species, Green rabbitbrush (Chrysothamnus viscidiflorus) was associated with increased densities of native annual species, and Sagebrush (Artemisia tridentata) was associated with increased numbers of rare native species. Our results indicate that areas dominated by sagebrush would have the greatest regenerative potential of native species within their seed banks.
Sites that burned <10 years ago had greater similarity between above-ground and seed bank species composition, primarily due to low diversity and/or an abundance of invasive species.
Field surveys of shrub and ground cover may be useful tools for predicting seed bank characteristics in areas of sagebrush-steppe vegetation, and may help prioritize restoration activities after disturbance.
Barga S, Leger EA. 2018. Shrub cover and fire history predict seed bank composition in an arid shrubland. Journal of Arid Environments 154: 40-50.