Patterns of root colonization by arbuscular mycorrhizal fungi and dark septate endophytes across a mostly-unvegetated, high-elevation landscape

Abstract

Arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) are two fungal groups that colonize plant roots and can benefit plant growth, but little is known about their landscape distributions. We performed sequencing and microscopy on a variety of plants across a high-elevation landscape featuring plant density, snowpack, and nutrient gradients. Percent colonization by both AMF and DSE varied significantly among plant species, and DSE colonized forbs and grasses more than sedges. AMF were more abundant in roots at lower elevation areas with lower snowpack and lower phosphorus and nitrogen content, suggesting increased hyphal recruitment by plants to aid in nutrient uptake. DSE colonization was highest in areas with less snowpack and higher inorganic nitrogen levels, suggesting an important role for these fungi in mineralizing organic nitrogen. Both of these groups of fungi are likely to be important for plant fitness and establishment in areas limited by phosphorus and nitrogen.

Biotic and abiotic factors shape arbuscular mycorrhizal fungal communities associated with the roots of the widespread fern Botrychium lunaria (Ophioglossaceae)

“…However, on the regional or global scale, knowledge about the molecular diversity of AMF communities in high altitudes (> 2000 m a.s.l.) remains poor (Bueno de Mesquita et al ., ). Here, we showed both the taxonomic diversity and the community structure of the AMF associated with the roots of the fern Botrychium lunaria from alpine grasslands at 2400 m a.s.l.…”

Plant diversity and density predict belowground diversity and function in an early successional alpine ecosystem

“…How different plant community properties (including composition) are drivers of specific soil groups at this site are discussed elsewhere (e.g., Bueno de Mesquita et al. ).…”

“…Since density strongly correlated with richness, both variables likely play a role in the effects on soil biota. How different plant community properties (including composition) are drivers of specific soil groups at this site are discussed elsewhere (e.g., Bueno de Mesquita et al 2018b).…”

Growing‐season length and soil microbes influence the performance of a generalist bunchgrass beyond its current range

“…Although a metanalysis of dark septate endophyte effects on plant growth demonstrated typically beneficial effects (Newsham 2011), their function is still open to debate (Mandyam and Jumpponen 2015), as some studies have shown that they can negatively impact plant growth (Alberton et al 2010, Mayerhofer et al 2013), and have not benefited as wide a range of plants as arbuscular mycorrhizal fungi. However, DSE may play a relatively more important role in alpine ecosystems, where they are found in most plant species (Bueno de Mesquita et al 2018 a ). Other important fungal genera identified in the sequencing data include the pathogen Venturia , and the saprotrophs Fontanospora , Pseudogymnoascus , and Knufia (Rikkerink et al 2011, Crous et al 2013, Tedersoo et al 2014, Nguyen et al 2016).…”