Soil communities are often degraded in mined sites, and facilitating the recovery of soil mutualists such as arbuscular mycorrhizal fungi (AMF) may assist with the restoration of native plants. At a grassland mine restoration site, I compared a commercial AMF inoculum with soil collected from beneath native grasses as a source of inoculum, as well as a control treatment. Field plots were broadcast‐inoculated and seeded with native grasses, and biomass of native and non‐native species was measured in three consecutive years. In addition, greenhouse‐grown seedlings of a native bunchgrass (Stipa pulchra) were inoculated with similar treatments, transplanted into the field, and assessed after 18 months. When broadcast inoculation was used, the local soil inoculum tended to increase non‐native grass biomass, and marginally decreased non‐native forb biomass in the second year of study, but did not significantly affect native grass biomass. Broadcast commercial inoculum had no detectable effects on biomass of any plant group. Stipa pulchra transplants had greater N content and mycorrhizal colonization, and marginally higher shoot mass and K content, when pre‐inoculated with local soil (relative to controls). Pre‐inoculation with commercial AMF increased AMF colonization of the S. pulchra transplants, but did not significantly affect biomass or nutrient content. The findings indicate that at this site, the use of local soil as an inoculum had greater effects on native and non‐native plants than the commercial product used. In order to substantially increase native grass performance, inoculation of transplanted plugs may be one potential strategy.

Within the invasion ecology literature, it is often noted that abiotically stressful environments are typically less invaded by non-native plants than nearby less-stressful environments. However, until now no one had collected and summarized examples of this pattern. This paper first compiles evidence that plant communities in many harsh habitats are less invaded, and then synthesizes possible explanations for this pattern. We discuss that harsh sites may be less invaded because, compared to moderate sites, they may receive lower propagule pressure, particularly from well-suited plants, and because their abiotic and biotic characteristics may make them inherently more resistant to invasion.

Since 1981, 365 papers have cited a rarity matrix organized along three axes: geographic range (GR) (large vs. small), habitat specificity (HS) (specialist vs. generalist), and local abundance (LA) (dense vs. sparse). In the wider ecology literature, research on the association between plant species distributions and life history traits has mainly focused on a single axis such as GR. However, the internal structure of species ranges is widely recognized as important. In order to determine if identifying different types of rarity leads to alternative conclusions regarding the causes and consequences of rarity, we created a dataset linking the seven types of rarity matrix and to reproductive ecology traits. We found associations between the axes and these traits in a dataset of 101 rare plant species culled from 27 papers. Significant traits included mating system and seed dispersal mechanism. Species with small GR are more likely to have ballistic or wind dispersal than biotically-mediated dispersal (abiotic:biotic ratio 3:1). Habitat specialist species with small GRs are more likely to have outcrossing mating systems compared to habitat specialists of large GR (16:1). These results show that, within rare species, the structure of rarity is important (e.g. habitat specialization is different from small GR) and should be identified when determining basic mechanisms of plant distribution and abundance.

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