Soils as agents of selection: feedbacks between plants and soils alter seedling survival and performance

Abstract

Soils are one of the first selective environments a seed experiences and yet little is known about the evolutionary consequences of plant-soil feedbacks. We have previously found that plant phytochemical traits in a model system, Populus spp., influence rates of leaf litter decay, soil microbial communities and rates of soil net nitrogen mineralization. Utilizing this natural variation in plant-soil linkages we examined two related hypotheses:(1) Populus angustifolia seedlings are locally adapted to their native soils; and (2) Soils act as agents of selection, differentially affecting seedling survival and the heritability of plant traits. We conducted a greenhouse experiment by planting seedlings from 20 randomly collected P. angustifolia genetic families in soils conditioned by various Populus species and measured subsequent survival and performance. Even though P. angustifolia soils are less fertile overall, P. angustifolia seedlings grown in these soils were twice as likely to survive, grew 24% taller, had 27% more leaves, and 29% greater above-ground biomass than P. angustifolia seedlings grown in non-native P. fremontii or hybrid soils. Increased survival resulted in higher trait variation among seedlings in native soils compared to seedlings grown in non-native soils. Soil microbial biomass varied significantly across soil environments which could explain more of the variation in seedling performance than soil

The relative importance of rapid evolution for plant-microbe interactions depends on ecological context

“…Such changes in microbial communities could feedback to influence plant distributions, productivity and global nutrient cycles [20]. Thus, plant -microbe interactions may be some of the most generally relevant and strongest eco-evo feedbacks, but these interactions remain largely unexplored in studies quantifying eco-evo interactions ( [21], but see [22,23]). …”

Soil microbial community structure of range‐expanding plant species differs from co‐occurring natives

“…Studies on plant species-specific soil communities may also be helpful in further unravelling why plant-soil feedback effects may operate more strongly on rare plants than on dominants (Klironomos 2002). The strong effect of native plants on general microbial community composition in their own soils may explain why species can experience a 'home-field advantage' in decomposition and nutrient cycling (Gholz et al 2000;Chapman & Koch 2007;Ayres et al 2009;Pregitzer et al 2010;Suding et al 2013).…”

“…As many soil biota are relatively slow dispersers (Berg et al 2010), soil communities in the new range may not necessarily contain pathogens, decomposers and symbiotic mutualists from the native range. When compared with native plants, enemy release may cause a competitive advantage for exotic plant species in the invaded habitat (Walker et al 2003;van der Putten, Klironomos & Wardle 2007;Inderjit & van der Putten 2010), whereas nonadapted mutualists and decomposers may cause a disadvantage for plants that have moved away from their home fields (Richardson et al 2000;Chapman & Koch 2007;Ayres et al 2009;Pregitzer et al 2010). The question that we will address in the present study is how the rhizosphere community is influenced by exotic range-expanding plant species in comparison with congeneric plant species that are native in the invaded habitat.…”

Morphological and anatomical characteristics of Artemisia absinthium var. absinthium and its Polish endemic variety A. absinthium var. calcigena

“…Other differences could be maintained even when the same environmental conditions were applied to plants and were a result of interspecific variation occurring between natural populations. This could suggest the influence of natural selection (Øvstedal and Mjaavatten 1992;Pregitzer et al 2010).…”