Arbuscular mycorrhizal fungi and dark septate endophytes root colonization in Upper Green Lakes Valley, 2007-2016

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 levels,
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.