Climate change is altering the distribution and abundance of species around the globe. In response to changing climate, plants may go locally extinct, migrate to new regions that meet habitat requirements, or adapt to new conditions. Symbiotic associations with microorganisms, such as endophytes, may be a way that plants can rapidly adapt to new climate conditions and deal with increased stress. Fungal endophytes have been shown to confer benefits such as increased drought, temperature, and salt tolerance in many different species of plants. Semiarid rangelands are naturally variable and stressful environments, and resource variability is predicted to increase in the future under most climate change models. One might expect endophytes to play a role in mediating plant responses to the environment in these communities, yet little information is available on the presence, richness, function, or performance of endophyte-infected plants in semiarid systems. I examined populations of two native grasses, Elymus multisetus and Poa secunda, to determine if plants contained fungal endophytes, the richness of endophyte morphotypes, and whether either varied by site environmental conditions. Plant leaf tissue of ten plants from two populations of P. secunda and four populations of E. multisetus were collected. Three leaves per plant were sterilized, plated on potato dextrose agar, and incubated at 25°C. Plates were scored visually and microscopically for endophyte frequency and richness.
Results indicate that both E. multisetus and P. secunda plants harbor endophytic fungi, and further that some endophyte morphotypes are shared, while others are unique to each grass species. The frequency of endophyte infection was 100% for E. multisetus, and ranged from 50 to 100% in P. secunda depending upon sampling location. Endophyte richness varied by location for both species, with more mesic communities tending to have a greater richness of endophyte morphotypes. The highly heterogeneous nature of resources within arid ecosystems combined with the potential for endophytes to improve plant response to environmental stress suggests that the presence of these symbiotic associations may be fundamental for plant survival in arid ecosystems, and may be able to mitigate the effects of climate change on semiarid rangeland plants. Future studies will examine the functional role of select fungal endophytes on plant performance to determine if plant performance can be increased under more stressful climate conditions.