Dirt: Biogeography of the Pacific Crest Trail

This is a collaborative project by Christina Agapakis and Ellie Harmon, supported by the University of California Institute for Research in the Arts. While hiking the Pacific Crest Trail, Ellie collected samples of dirt throughout California and sent them to Christina's lab. They extracted DNA from the bacteria living in the dirt and sequenced the 16S ribosomal RNA to identify what species of bacteria were there. Click on a picture to see a summary of the bacterial species living in the sample.

Collection site 2: Mile 40, just before Mt. Laguna, clearing in a forest.

Collection site 2: Mile 40, just before Mt. Laguna, on trail.

Collection site 1: One mile from the border, under a bush.

Collection site 1: One mile from the border, in a grassy field.

Collection site 1: One mile from the border, on the trail.

Collection site 4: Mile 179.5, Devil's Slide Trail, on the trail.

Collection site 3: Mile 88, Scissor's Crossing, under a juniper bush in the burn zone.

Collection site 3: Mile 88, Scissor's Crossing, ashes near a burned plant.

Collection site 3: Mile 88, Scissor's Crossing, on the trail in the burn zone.

Collection site 2: Mile 40, just before Mt. Laguna, beneath a dead tree.

Collection site 5: Mile 256.6, Spring before Big Bear, on the trail, away from the spring.

Collection site 5: Mile 256.6, Spring before Big Bear, in the spring, off the trail.

Collection site 5: Mile 256.6, Spring before Big Bear, where the spring crosses the trail.

Collection site 4: Mile 179.5, Devil's Slide Trail, decaying log.

Collection site 4: Mile 179.5, Devil's Slide Trail, under rocks.

Collection site 6: Mile 333.7, Campsite before Cajon, yellow flower.

Collection site 6: Mile 333.7, Campsite before Cajon, in campsite.

Collection site 6: Mile 333.7, Campsite before Cajon, off trail.

Collection site 6: Mile 333.7, Campsite before Cajon, on the trail.

Collection site 5: Mile 256.6, Spring before Big Bear, away from the spring, off the trail.

Collection site 10: Mile 650, Just before walker pass, on the trail.

Collection site 7: Mile 429.2, Roadwalk near Mt. Gleason, base of a burned tree.

Collection site 7: Mile 429.2, Roadwalk near Mt. Gleason, clay about three inches deep.

Collection site 7: Mile 429.2, Roadwalk near Mt. Gleason, from a crack in the road.

Collection site 7: Mile 429.2, Roadwalk near Mt. Gleason, topsoil.

Collection site 11: Mile 754, Entering Sequoia National Park, hillside, two inches deep.

Collection site 11: Mile 754, Entering Sequoia National Park, hillside topsoil.

Collection site 11: Mile 754, Entering Sequoia National Park, on the trail.

Collection site 10: Mile 650, Just before walker pass, yellow flower.

Collection site 10: Mile 650, Just before walker pass, hillside.

Collection site 14: Mile 865.6, Selden Pass, on the trail.

Collection site 13: Mile 768, Kearsarge Pass, under a rock.

Collection site 13: Mile 768, Kearsarge Pass, on trail.

Collection site 12: Mile 767, Summit of Mt. Whitney.

Collection site 11: Mile 754, Entering Sequoia National Park, under an old foxtail pine.

Collection site 15: Mile 886.5, Squaw Lake, trees.

Collection site 15: Mile 886.5, Squaw Lake, lake outlet.

Collection site 15: Mile 886.5, Squaw Lake, on the trail.

Collection site 14: Mile 865.6, Selden Pass, flowers.

Collection site 14: Mile 865.6, Selden Pass, snowmelt.

Collection site 17: Mile 1073, Near brightly colored rocks, sample 2.

Collection site 17: Mile 1073, Near brightly colored rocks, sample 1.

Collection site 16: Mile 1013.97, Sonora Pass, under a juniper tree.

Collection site 16: Mile 1013.97, Sonora Pass, under small plants along the trail.

Collection site 16: Mile 1013.97, Sonora Pass, on the trail.

Collection site 19: Mile 1190.5, On the way into town, on the trail, sample #2.

Collection site 18: Mile 1190.5, On the way into town, roots of a legume plant, sample #1.

Collection site 18: Mile 1190.5, On the way into town, near a manzanita.

Collection site 18: Mile 1190.5, On the way into town, on the trail, sample #1.

Collection site 17: Mile 1073, Near brightly colored rocks, sample 3.

Collection site 21: Mile 1368, Burn Zone near Lassen National Forest.

Collection site 20: Mile 1134.9, Before Chester, under a plant with a fuzzy leaf.

Collection site 20: Mile 1134.9, Before Chester, very cold dirt near the trail.

Collection site 20: Mile 1134.9, Before Chester, on the trail.

Collection site 19: Mile 1190.5, On the way into town, roots of a legume plant, #2.

Collection site 21: Mile 1368, Burn Zone near Lassen National Forest.

Collection site 21: Mile 1368, Burn Zone near Lassen National Forest, ashes.

Collection site 21: Mile 1368, Burn Zone near Lassen National Forest, area with no new growth.

Collection site 21: Mile 1368, Burn Zone near Lassen National Forest, new plant growth in burn dirt.

Collection site 21: Mile 1368, Burn Zone near Lassen National Forest, area with new plant growth in rocks.

Collection site 22: Mile 1663.7, Fern spring after Seiad Valley, spring sludge.

Collection site 22: Mile 1663.7, Fern spring after Seiad Valley, trail mud created by spring runoff.