Tag Archives: science

Over sixty years digging and we’re still finding new ‘dirt’ on HJ Andrews

One kilometer. Or roughly ten football fields. That’s the extent of the area over which Karla Jarecke, a Ph.D. candidate in the College of Forestry’s Department of Forest, Ecosystems & Society can feasibly navigate her way through the trail-less HJ Andrews Experimental forest to collect the data she needs in a typical day of field work. Imagining a football field is perhaps not the best way to appreciate this feat, nor envision the complex topography that makes up this coniferous forest on the western flanks of the Cascade mountains, roughly 50 miles East of Eugene. But these characteristics are precisely what have made this forest valuable to scientists since 1948 and continue to make it the ideal place for Karla’s research.

Experimental watersheds like the HJ Andrews forest were established initially to understand how clear-cutting influenced forest drainage and other ecosystem processes such as regrowth of plants and change in nutrients in soils and streams. This was during the time when timber-take was increasing and we still had little understanding of its ecosystem effects. Karla’s work is also forward-thinking, but less on the lines of what will happen to drainage when trees are removed and more focused on understanding the availability of water for trees to use now and in the future. She wants to know what influence topography has on plant water availability in mountainous landscapes.

Meter deep soil pits at Karla’s field site.

Back to bushwhacking. The answer to Karla’s research question lies beneath the uneven forest floor. Specifically, in the soil. Soil is the stuff made up of weathered rock, decomposing organic material and lots of life but it is also the medium through which much of the water within a forest drainage moves. Across her study area, Karla has 54 sites where she collects data from sensors that measure soil moisture at two different depths. These steel rods send electrical currents into the ground, which depending on how quickly they travel can tell her how much water is present in the soil. She also keeps track of sensors that measure atmospheric conditions, like temperature and air humidity. This information builds on the incredible sixty-year data set that has been collected on soil moisture within HJ Andrews, but with a new perspective.

Digging soil pits on steep slopes occasionally required stacking logs at the base of a tarp to prevent the soil from sliding down the hill.
Photo credit: Lina DiGregorio

Karla explains that there have been long-standing assumptions surrounding elevation gradients and their control on water availability in a forest system. This understanding has led to modeling tools currently used to extrapolate soil moisture across a landscape. But so far, her data show huge variability on surprisingly small scales that cannot be explained by gradient alone. This indicates that there are other controls on the spatial availability of soil moisture in such mountainous terrain.

“We’re finding that model doesn’t work really well in places where soil properties are complicated and topography is variable. And that’s just the first part of my research.”

The next phase of Karla’s work seeks to evaluate tree stress in the forest and determine if there are any connections between this and the variability she is finding in soil moisture across spatial scales. True to the complex nature of the landscape, this work is complicated! But to Karla, it’s important. Growing up in the mid-west, Karla came to know water as “green” and when she moved West, first to fulfill an internship in Colorado and then to pursue her graduate work here in the Pacific Northwest, she was (and still is) amazed by the abundance of clean, clear rivers and streams. And it’s something she doesn’t ever want to take for granted.

Karla and her sister Stephani snowshoeing on Tumalo Mountain in the Cascade Range of central Oregon.

To find out more about Karla’s research and her journey from farming in Italy to studying soil, tune in on Sunday, October 27th at 7 PM on KBVR 88.7 FM, live stream the show at http://www.orangemedianetwork.com/kbvr_fm/, or download our podcast on iTunes.

Karla’s episode on Apple Podcasts

Comunicación Científica con Franco

Kristen Finch interviewing Francisco Guerrero for this special episode. (Photo by Adrian Gallo)

This week on Inspiration Dissemination we will be featuring a previous guest: Francisco Guerrero, a PhD student in the Department of Forest Engineering, Resources, and Management. Francisco’s first interview aired on October 18, 2015, and we called him back for a follow-up because he has been selected for the American Association for the Advancement of Science (AAAS) Mass Media Science and Engineering Fellowship. As a fellow, Franco will be writing feature stories about climate change and health for CNN en Español. Part of the fellowship will involve helping with film production, as well. FUN FACT last time Franco was on the show, he told us that he always wanted to be a movie producer. Franco will take this amazing opportunity during the final push for his PhD research to enhance his science communication skills and gain experience in production and video broadcasting.

This special interview will begin at 6:30 pm on May 6, 2018. We will be asking Franco about the application process, his responsibilities as a fellow, and his goals for the fellowship. After our interview with Franco, we will rebroadcast his first interview on Inspiration Dissemination at 7 pm.

Tune in to KBVR Corvallis 88.7 FM at 6:30 pm to hear about the AAAS Fellowship and learn about Franco’s research in the College of Forestry. Not a local listener? No sweat! Stream the show live on line or hear the podcast next week.

Franco wants to hear from you! Tweet him with ideas for CNN Español, specifically stories about Climate Change and Health. 

The folks behind the episode: Francisco Guerrero, Kristen Finch, and Lillian Padgitt-Cobb. (Photo by Adrian Gallo)