Biology ETDs

Publication Date

Fall 11-12-2020


Few studies have examined inoculum potential of ectomycorrhizal fungi (EMF) in the absence of plant hosts, yet persistence of these fungi may be paramount to resilience of Pinus edulis and other mycorrhizal plant species. We conducted a study in which seven sites were selected in northwestern New Mexico with known dates of P. edulis extirpation and a lack of regeneration. Age classes included: two sites extirpated 10-20 years ago, two extirpated 55-65 years ago, two extirpated 500+ years ago, and one extirpated 11,000+ years ago. At each site, two plots were paired: an extirpated plot and the nearest live adult P. edulis stand. Soil samples were collected from each plot at 0-5 cm and 20-25 cm depths from four locations. Pinus edulis seedlings were inoculated with field soils in a greenhouse bioassay to measure EMF inoculum potential. Colonization by EMF occurred across sites, and inoculum potential decreased significantly from zero to 16+ years post extirpation. Tree biomass was unaffected by EMF colonization. Communities of EMF in extirpated and live plots differed significantly and were dominated by Geopora, Rhizopogon, and Tomentella. Geopora was the only genus found in sites older than 65 years and possibly arrived by dispersal. Trees grown in soils collected from 0-5 cm had significantly greater colonization rates and associated EMF diversity. Sites where P. edulis was extirpated via drought had less diverse EMF communities dominated by Geopora. The results of this study will help guide restoration efforts for P. edulis and other ectomycorrhizal tree species.




ectomycorrhiza, piñon pine, climate change, drought, pine extirpation, inoculum potential

Document Type


Degree Name


Level of Degree


Department Name

UNM Biology Department

First Committee Member (Chair)

Dr. Lee Taylor

Second Committee Member

Dr. Kim Eichhorst

Third Committee Member

Dr. Jennifer Rudgers