Invasive Species Compendium

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Abstract Full Text

Effect of the invasion of Nicotiana glauca on the functionality of the soil microbial community in Mediterranean semi-arid ecosystems.

Abstract

Invasive alien plants are capable of altering the composition and function of the soil microbial community, facilitating their invasion. We start from the hypothesis that (i) the invasion of Mediterranean semi-arid ecosystems by Nicotiana glauca would promote a microbial community in its rhizosphere with specific functions and (ii) the functionality of the microbial community of the rhizosphere associated with the invasive plant would be independent of the edaphic characteristics of the invaded site. We tested these hypotheses at four sites with different edaphic characteristics. These locations included two ecosystems altered by man and two natural Mediterranean ecosystems with inhospitable characteristics for plants (a saline and a gypsiferous soil), where N. glauca formed stands mixed with the corresponding native plant communities. The microbial function of the rhizosphere was estimated using the PICRUSt and FUNGuild algorithms. The microbial functions of the rhizosphere differed between the invasive plant and the dominant native plant species. In the microbial community of the rhizosphere of the invasive plant, the bacterial functions involved in the metabolism of carbon and sulfur compounds as well as the saprophytic guilds of the fungal community predominated. Soil respiration and enzymatic activities related to the nutrient cycle reached lower values in the rhizosphere of N. glauca plants invading saline and gypsum soils. In conclusion, N. glauca produced changes in the functionality of the soil microbial community in Mediterranean semi-arid ecosystems, including soils affected by salinity and gypsum.