These Trees Have Quite A Story To Tell
Lead. Fires. Floods. Drought.
For hundreds of years, the ancient bristlecone pine trees on the Pennsylvania Mountain Natural Area have been writing their autobiographies and painting a picture of how the environment has changed over time.
Regis University Professor John Sakulich, a biogeographer and forest ecologist, has been studying and collecting data from bristlecone pines and working with students to analyze centuries of climate, chemistry and the natural environment of trees living in high altitude conditions.
On the top of a 11,800’ peak, conservationists and community
members ranging in age from 11 to 75-years-old joined Sakulich to learn about Dendrochronology. This is the science of dating events, environmental change, and archaeological artifacts by using the characteristic patterns of annual growth rings in timber and tree trunks.
“The oldest tree we’ve discovered in this area is around 1,500 years old. We know the bristlecone pines can live up to 2,500 years,” Sakulich shared with those who attended the “Be A Citizen Scientist Dendrochronology Workshop” with Mountain Area Land Trust (MALT) in Fairplay.
“A tree grows a ring one time a year…light wood is early wood, while darker wood is later wood. The different widths of tree rings differ from year to year. We see wider rings in wetter years and narrower rings during dry years,” he said. Tree rings also have different density and chemistry, which gives scientists insight into the conditions during a point in time. For instance, Sakulich and students have detected lead in tree rings when mining was at its prime. He has also seen dark burn scars on trees that survived a wildfire.
“In this area, we discovered a fire killed part of a pine in 1801, but it was able to heal and continue living. The rings and burn scars also showed other fires around 1830, 1857 and the early 1900s. During this time, fires typically killed the smaller trees in the area, while the older more mature trees were able to survive.”
Information like this is important to foresters and fire
departments that use data to determine where to conduct prescribed burns and fire mitigation. Because of Sakulich’s research, Denver Mountain Parks periodically uses the tree ring data and tree burn scar information to determine an area’s natural fire history. This information is vital to guiding the department’s efforts to manage parks.
To add to Regis University’s tree data research collection, Sakulich taught citizen scientists how to take a core sample from ancient bristlecone pine trees using an increment borer, which is a specialized steel tool used to extract a section of living wood tissue.
Participants learned how to gently insert the increment borer near the base of the bristlecone pines to extract a small skinny core. From there, citizen scientists spread out over several acres to collect samples from more than 20 trees measuring in size from 64” to 94” in diameter.
Kimberly Rose, a naturalist, eco-therapist, educator and citizen scientist shared, “The day was educational, experiential, and contributed to local climate science. Spending quality and purposeful time with the bristlecone pines up on MALT’s beautiful Pennsylvania Mountain while serving with other community members is so meaningful to me, personally. As a community naturalist, it is important to always be learning and teaching up-to-date environmental information.”
Rose intends to share the lessons she learned with program participants enrolled in Relational Wilding, an organization she owns and manages that offers nature education programs, eco-therapy and mentorship for all ages.
“Mountain Area Land Trust enjoys partnering with our
community to host educational workshops like these,” Executive Director Lynn Caligiuri said. “It was inspiring to have John share his passion and knowledge of ancient bristlecone pines with a dozen citizen scientists, who will in turn pass the lessons they’ve learned onto their own friends and families.”
This fall, Sakulich and his students will take a close look at the core samples as a way to teach them about dendrochronology. Students will use high resolution scanners to decipher tree ring data and place the cores on a microscope with a micrometer to determine the age of the trees. The information provided will be documented and shared with other researchers studying climate change.
“We are grateful to John and the many other scientists that have conducted critical high-altitude research on the Pennsylvania Mountain Natural Area. The data that has been gathered over time provides an important story of the history of the natural resources of this region and what may happen in the future. This is why we do the work we do; to save the land and leave a lasting legacy for generations to come,” Caligiuri shared.
Learn more about Regis University Professor John Sakulich and his research work here.
