Contrasting dynamics of seed banks and standing vegetation of annuals and perennials along a rainfall gradient

The soil seed bank is a major component of plant communities. However, long-term analyses the dynamics and ensuing vegetation are rare. Here, we studied in communities with high dominance annuals Mediterranean, semiarid, arid ecosystems for nine consecutive years. For annuals, hypothesized that density would be more stable than standing herbaceous vegetation. Moreover, predicted differences temporal variability between increase aridity, where year-to-year rainfall higher. We found at population level (assessed as standard deviation loge-transformed density) dominant each site did not differ any sites. total patterns depended on aridity. In Mediterranean site, was similar (0.40 vs. 0.40). Still, semiarid sites, lower (0.49 1.01 0.63 1.38, respectively). This difference population-level can related to synchrony their bank. contrast, perennials (all species combined), higher Overall, our results highlight role buffering annual increasing climatic uncertainty typical aridity gradients. crucial under imposed by change region.