Invasive plants affect arbuscular mycorrhizal fungi abundance and species richness as well as the performance of native plants grown in invaded soils

Abstract

We studied the effects of invasions by three plant species: Reynoutria japonica, Rudbeckia laciniata, and Solidago gigantea, on arbuscular mycorrhizal fungi (AMF) communities in habitats located within and outside river valleys. Arbuscular mycorrhizal colonization, AMF abundance and species richness in soils were assessed in adjacent plots with invaders and native vegetation. We also quantified the performance (expressed as shoot mass, chlorophyll fluorescence, and the concentration of elements in shoots) of two common, mycorrhizal native plants, Plantago lanceolata and Trifolium repens, grown in these soils. The invasions of R. japonica, R. laciniata, and S. gigantea influenced AMF communities compared to native vegetation, but the changes depended on the mycorrhizal status of invaders. The effects of non-mycorrhizal R. japonica were the most pronounced. Its invasion reduced AMF abundance and species richness. In the plots of both mycorrhizal plants, R. laciniata and S. gigantea, we observed decreased AMF species richness in comparison to native vegetation. The AMF community alterations could be due to (i) depletion of organic C inputs to AMF in the case of R. japonica, (ii) plant secondary metabolites that directly inhibit or selectively stimulate AMF species, or (iii) changes in soil physicochemical properties induced by invasions. The effect of invasion on AMF abundance and species richness did not generally differ between valley and outside-valley habitats. The invasions affected photosynthetic performance and the concentrations of elements in the shoots of P. lanceolata or T. repens. However, the directions and magnitude of their response depended on both species identity and the mycorrhizal status of invaders.

Arbuscular mycorrhizal fungal community assembly in the Brazilian tropical seasonal dry forest

“…Several studies (e.g., Richardson et al 2000;Hawkes et al 2006;Rodríguez-Echeverría et al 2009;Oehl et al 2010;Carneiro et al 2015;Souza et al 2016b) also showed a lower AMF diversity in disturbed soils by biological invasion of invasive exotic species (e.g., A. senegal, A. seyal, A. albida, E. albensis, Olpidium spp., Cryptostegia madagascariensis, Sesbania virgata, P. juliflora, and Parkinsonia aculeata) in comparison with soil in natural conditions. These results are in agreement with previous studies (Soumare et al 2015;Ayanu et al 2015;Zubek et al 2016;Callaway et al 2008;Tanner and Gange 2013) and support our hypothesis that invasive plants are associated with specific AMF species. As a consequence, P. juliflora seemed to be in advantage comparing with M. tenuiflora by profiting from beneficial AMF species (e.g., AMF from the order Glomerales) (Shah et al 2009).…”

“…These results are in agreement with previous work (Soumare et al 2015;Majewska et al 2015) that reported higher values of soil pH and available P in the root zone of invasive exotic plants, such as Acacia senegal, Acacia seyal, Acacia albida, Eragrostis albensis, and Olpidium spp. By altering the chemical properties of the soil below their canopy, invasive plant species may alter the nutrient cycle (Follstad Shah et al 2010) and thus may be responsible for the modification AMF community composition in the EXO soils (Zubek et al 2016;Zubek et al 2013). …”

“…First, invasive exotic plant species usually form large monospecific plant populations, thus reducing the diversity of hostplants available to the AMF community. Second, metabolites produced by invaders negatively affect native plants growth by disrupting their mutualistic associations with the AMF community from native soils (Zubek et al 2016). Finally, the introduction of invasive exotic plant species might cause changes in soil chemical properties that may indirectly affect AMF community composition and, thus, contribute to a successful establishment and spread of invasive exotic plant species (Shah et al 2009).…”

Differential influence of four invasive plant species on soil physicochemical properties in a pot experiment

“…plants change the abundance, diversity, and structure of plant and animal communities (Hejda et al 2009;Lenda et al 2013), and often considerably modify physicochemical and biological properties of the soil environment, thereby potentially affecting key ecosystem processes (Vilà et al 2011;Castro-Díez et al 2014;Majewska et al 2015;Stefanowicz et al 2016;Zubek et al 2016;Broadbent et al 2017;CastroDíez and Alonso 2017;Lavoie 2017;Rodríguez-Caballero et al 2017).…”

Role and influence of soil microbial communities on plant invasion

“…The invasion of another nonmycorrhizal plant, Reynoutria japonica Houtt. decreased the species richness and AM fungal abundance due to reduction of organic carbon inputs (Zubek et al, 2016). AM fungi enhance the extensive spread and invasiveness of Solidago canadensis more than the native Stipa bungeana Trinius plant species (Sun & He, 2010).…”