Life
To collect the annual mortality and recruitment data at the YFDP, we establish a field camp for two weeks each year and collect data with a team of 15-25 students, researchers, and professional field staff.

Camping at Yellow Pine Volunteer Campground in 2009. Molly Barth and Alana Lautensleger work on dinner while the USGS crew discusses ecological theory.

Many of the field participants at YFDP do so as part
of the Ecology of the Sierra Nevada and White Mountains class run through USU, UW, and UM. Here the entire 2011 class gathers opposite Bridalveil Falls on a day off (it rained 9.5 cm the night before).
Back at the Hodgdon Meadow Campground, a student assambled a sap-catcher/shade tarp above her tent. Unfortunatly, this tarp did little to protect against the 9.5 cm (!) that came several days later.

Upon arrival at Yosemite National Park, YFDP principal investigator, Jim Lutz, gets right to work in accounting for all the field supplies

A shot of the 2011 field crew campsite at Hogdon Meadows. This was home to the researchers, students, and the USGS crew while working on the plot. Students prepare to learn the basics of wilderness navigation from PI Lutz on top of Lembert Dome. Lembert dome is at the east end of Tuolumne Meadows at 2,880 m.
Kaitlyn Schwindt, Sienna Hiebert, and Sam Barr (left
to right) fill the three water jugs that provide water to the crews while at camp. When full these jugs can weigh over 20 kg - Whew!
After a long day on the plot, the crew can't get enough chips and salsa. Good thing Jim Lutz (meal planner) came prepared. The crew hastily prepares breakfast and lunch before a long day on the plot. A nice meal, hot coffee, and anticipation of the days work is enough to get this crew up at 6am and rolling by 7am.
A view from the fire lookout at Crane Flat Helitack shows the Yosemite hotshot crew hard at work. The crew worked hard to put out a wildfire which can be see in the distance. This helitack is located near the most assessable plot entrance. Each day before heading out to resume the mortality survey, teams of 3 to 4 regroup and account for the necessary equipment. PI Jim Lutz, poses for a picture while identifying the cells four corners. This is the first step upon entering each cell.
Senior Investigator Alina Cansler fixes a transect line during the survey. Although the plot has a variety of geographic features, this picture shows the slope characteristic of most of the grids in the plot.Tree 03-0139 has been found! When a tree is found the crew member calls out the trees tag number, species, and whether it is dead or alive. Kimberly Grant uses the quadrat map to direct fellow crew members. During the mortality survey, no grid cell is complete until all the mapped trees are accounted for.

A large Pinus lambertiana was struck by lightning in 2010. This tree was still alive during the 2011 mortality survey, but showed signs of diminishing health, and was found dead in 2012. Here PI Larson and Senior Investigator Alina Cansler pose examine the two adjacent trees with lightning scars.

A massive Pinus lambertiana snag stands among a group of Abies concolor and Calecedrus decurrens.
All these species are abundant in the 25.6 ha plot and are commonly associated with mixed-conifer forests throughout the Sierra Nevada.
Undergraduate crew members, Kimberly Grant (UW) and Katie Meline (WSU), work together to determine the charateristics, condition codes (CCs), and factors assosiated with death (FADs) for this dead tree.
Conks are commonly seen on both dead and alive trees. The YFDP mortality survey records conks as condition code number 19. This picture shows a very large conk, but they aren't always as large (see next picture). The cankers on this Pinus lambertiana are undoubtedly a result of White Pine Blister Rust. Visibility of these cankers are evidence that the tree was infected at least several years ago. Although it is a common killer of white pines in North America, it was found in lower than expected abundance in the plot. Condition code 24: Pitch!
The horizontal galleries on this Abies concolor provide the field crew with sufficient evidence that the culprit killer was Scolytus ventralis. YFDP protocol calls for a thorough assessment of all the conditions and factors related to each mortality. Scolytus ventralis is the most common fir killer on the plot, and is frequently associated with the fungal pathogen, Armillaria. This photo shows the fungal pathogen Armillaria. Armillaria is commonly found under the bark near the bole or in the soil around an infected tree. Bole damage is considered a factor that usually leads to a mortality.
Washington State University undergraduate student, Nicole Studevant carefully records measurements during a mortality assessment. The Yosemite Forest Dynamics plot crew pride themselves on the meticulous recording of data. University of Washington student, Rachel Mickey, measures the height of a possible in-growth. Although the mortality survey was the main focus of the 2011 field crew, All trees that are 1 cm or more at breast height are mapped into the plot. Nick Mills, a crew member from Eastern Connecticut State University, uses the impulse laser to determine a horizontal distance measurement. This measurement is taken to determine the coordinates of trees that grow into the plot.
Washington State University undergraduate student, Nicole Studevant carefully records measurements during a mortality assessment. The Yosemite Forest Dynamics plot crew pride themselves on the meticulous recording of data. University of Washington student, Rachel Mickey, measures the height of a possible in-growth. Although the mortality survey was the main focus of the 2011 field crew, All trees that are 1 cm or more at breast height are mapped into the plot.