Great Basin, Desert Experiment Range, Utah
The Desert Experimental Range, often called the DER and operated by the U.S. Forest Service, was established in 1933 when President Hoover designated the 87 sq mile plot as an agricultural range experiment station. Since then the DER has become a center for cold-desert rangeland research and a range ecology educational site of international significance. In 1976, the DER was designated a Biosphere Reserve by the United Nations Educational, Scientific, and Culture Organization (UNESCO) under the Man and the Biosphere (MAB) program with 740 ha Desert Research Natural Area as the core protected area. It currently is just one of the few cold desert biomes worldwide. Unfortunately, the DER has become infested with non-native invasive plants that are displacing native plants. One invasive plant (Halogeton glomeratus) forms invasion zones and chemically alters the soil so it becomes inhospitable to the native plant Ceratoides lanata. We are studying how the relationship between plants (H. glomeratus and C. lanata) and fungal endophytes change throughout the invasion process.
Antarctic Dry Valleys
Taylor valley near McMurdo station contains three large ice-covered lakes, glaciers and several tall mountain peaks. The flow of ice from the south pole is blocked from entering into the dry valleys so they are ice-free and have a mixture of rock and sand substrate. Other than occasional mosses that grow near glaciers and algae that bloom when ice ponds and edges of the lakes thaw each year, there is no plant life in the valleys. However, there is a diverse soil microbial community consisting of fungi, bacteria and a few invertebrate species. As part of a National Science Foundation funded research team we began to study the ecology of fungi in dry valley soils to determine how the fungi survived in such low nutrient (oligotrophic) habitats and to develop methods to study soil fungi in temperate habitats of North America. We found a diversity of single-celled fungi (yeasts) and filamentous fungi and are characterizing biochemical pathways involved in carbon and nitrogen metabolism.
Methow Valley Wildlife Refuge, Washington
The Methow valley in north central Washington comprises a mixture of grassland, shrub-steppe and subalpine habitats. The valley has a history of grazing and farming and has been invaded by a number of non-native species including knapweeds, Hoary cress, cheat grass, bulbous bluegrass, kochia and thistles. In collaboration with refuge staff we have been characterizing the endophytes from these invasive plants and adjacent native plants. Currently, we are studying the ecological roles of the endophytes and determining if they play a role in the invasion process.
Mt. Everest - Nepal/Tibet
Working in conjunction with Adventurers and Scientists for Conservation (ASC), we have obtained samples of the plants growing at the highest elevations on earth. There is a moss species that grows in granite slabs at an elevation of 21,000 ft (6,420 meters) on Mt. Everest. Working with expedition leaders and ASC, samples were collected using proper scientific methods and analyzed for the presence of symbiotic fungal endophytes living inside plant tissues. We have isolated several species of fungal endophytes and are working to determine the ecological significance of the symbiosis and potential applicability in agriculture.
Shaw Island, Washington
Shaw island is in the San Juan Archipelago in Puget Sound. American dunegrass (Leymus mollis) is a plant capable of growing from beach habitats where high tides inundate root zones exposing the plants to seawater up cliffs and onto grasslands atop the cliffs. We have demonstrated that plants growing in the beach habitat are symbiotic with a fungal endophyte that confers salt tolerance and plants do not survive there without the endophytes. As the plants grow up cliffs they experience decreasing soil salinity until they reach the grassland where salt levels are minimal. We are studying the relationship between American dunegrass and fungal endophytes as salt levels change along the environmental gradient from beach to grassland.
Yellowstone National Park, Wyoming
The Yellowstone caldera has created a diversity of geothermal habitats that vary according to temperature, moisture and CO2 emissions. Our studies of plants thriving in geothermal soils revealed that they were symbiotic with a fungal endophyte that confers heat tolerance and without the endophytes plants could not survive the heat stress. Later, we found that the fungus contained a virus that was required for the fungus to confer heat tolerance to plants. We are currently working to understand the communication between the fungus and plant in concert with colleagues studying the fungus-virus communication. In addition, we are working with endophytes from plants growing in sink holes with high levels of CO2 to determine how plant-fungal relationships will be effected as atmospheric levels of CO2 continue to rise.