Species-specific influences of shrubs on the non-dormant soil seed bank of native and exotic plant species in central-northern Monte Desert
Article first published online: 27 MAR 2012
© 2012 The Authors. Austral Ecology © 2012 Ecological Society of Australia
Volume 38, Issue 1, pages 87–94, February 2013
How to Cite
ROLHAUSER, A. G., D'ANTONI, M. J., GATICA, M. G. and PUCHETA, E. (2013), Species-specific influences of shrubs on the non-dormant soil seed bank of native and exotic plant species in central-northern Monte Desert. Austral Ecology, 38: 87–94. doi: 10.1111/j.1442-9993.2012.02378.x
- Issue published online: 23 JAN 2013
- Article first published online: 27 MAR 2012
- Accepted for publication February 2012.
- invasion facilitation;
- Schismus barbatus;
- seed redistribution;
- vegetation nucleation;
- vegetation patch
Deserts shrubs are well known to facilitate vegetation aggregation, mostly through seed trapping, and stress amelioration during and after plant establishment. Because vegetation aggregation effects are a by-product of shrub presence, beneficiary species may not only be native, but also exotic. However, despite the high risk that exotic invasive species pose to ecosystem services, little is known of the role of desert shrubs on plant invasions. We assessed the influence of two shrub species on the non-dormant soil seed bank (i.e. the number of seeds that readily germinate with sufficient water availability) of an invasive annual grass (Schismus barbatus) and of coexisting native species in a central-northern Monte Desert (Argentina). Soil samples were collected beneath the canopies of two dominant shrub species (Bulnesia retama and Larrea divaricata) and in open spaces (i.e. intercanopies) in May 2001. Overall, the density of germinated seedlings of Schismus and that of the native species were negatively associated across microsite types. Schismus density was similar to that of all native species pooled together (mostly annuals), and was highest in Larrea samples (with no significant differences between Bulnesia and intercanopies). On the contrary, the density of all native species pooled together was highest in Bulnesia samples. Our results suggest that shrubs may contribute to plant invasions in our study system but, most importantly, they further illustrate that this influence can be species specific. Further research is needed to assess the relative importance of in situ seed production (and survival) and seed redistribution on soil seed bank spatial patterns.