【土壤生物与极端气候】Annelein Meisner Gerlinde B. De Deyn Wietse de Boer and Wim H. van der Putten. Soil biotic legacy effects of extreme weather events influence plant invasiveness. PNAS
Climate change is expected to increase future abiotic stresses on ecosystems through extreme weather events leading to more extreme drought and rainfall incidences [Jentsch A et al. (2007) Front Ecol Environ 5(7):365–374]. These fluctuations in precipitation may affect soil biota soil processes [Evans ST Wallenstein MD (2012) Biogeochemistry 109:101–116] and the proportion of exotics in invaded plant communities [Jiménez MA et al. (2011) Ecol Lett 14:1277–1235]. However little is known about legacy effects in soil on the performance of exotics and natives in invaded plant communities. Here we report that drought and rainfall effects on soil processes and biota affect the performance of exotics and natives in plant communities. We performed two mesocosm experiments. In the first experiment soil without plants was exposed to drought and-or rainfall which affected soil N availability. Then the initial soil moisture conditions were restored and a mixed community of co-occurring natives and exotics was planted and exposed to drought during growth. A single stress before or during growth decreased the biomass of natives but did not affect exotics. A second drought stress during plant growth resetted the exotic advantage whereas native biomass was not further reduced. In the second experiment soil inoculation revealed that drought and-or rainfall influenced soil biotic legacies which promoted exotics but suppressed natives. Our results demonstrate that extreme weather events can cause legacy effects in soil biota promoting exotics and suppressing natives in invaded plant communities depending on the type frequency and timing of extreme events.