Blog

Mariah’s paper, “Interannual precipitation controls on soil CO₂ fluxes in high elevation conifer and aspen forests,” has been published in Environmental Research Letters. This work is the result of a dozen years of field measurements (with some help from Andrew) at the Rocky Mountain Biological Laboratory in Gothic, Colorado. The analysis shows that soil CO₂ fluxes are sensitive to rainfall in the current growing season, as well as snowfall in the previous winter. Our newly-funded DOE project, leveraging the Snodgrass mountain transect, will build on these results.

Andrew’s review paper, “PhenoCam: An evolving, open-source tool to study the temporal and spatial variability of ecosystem-scale phenology,” which was solicited for the 60th anniversary Special Issue of Agricultural and Forest Meteorology, has now been published online. The review describes (1) the changing phenological research landscape, as represented by phenology-themed papers in AFM, over the last 60 y; (2) the contributions of phenocams and the PhenoCam Network, as reported in the pages of AFM, to the study of phenology; and (3) the lessons we learned from developing this grassroots effort. It also tells the story of the development and evolution of PhenoCam Network, and the fortuitious discoveries that led to PhenoCam. Thanks to AFM editors, Claudia Wagner-Riddle and Timothy Griffis, for the invitation to write this review!

Yujie and Mostafa attended the AmeriFlux meeting in central Massachusetts, which included a visit to Harvard Forest. Lab work presented at the meeting centered around the AmeriFlux Year of Remote Sensing theme. Yujie talked about her work on filling long gaps using boosted regression tree methods and including PhenoCam Gcc as a covariate, while Mostafa talked about canopy temperature measurements using thermal imaging. Andrew gave a virtual overview of PhenoCam (link to video), which was followed by former postdoc Adam Young’s presentation on integrating PhenoCam and tower flux measurements.

The usual group photo is below—who do you recognize?

In early October, Jenn Rudgers, Regents’ and Distinguished Professor of Biology at the University of New Mexico and Director, Sevilleta Long-Term Ecological Research Program, visited NAU and presented in the Ecoinformatics Seminar. Her seminar title was “Environmental variability at dryland ecotones: Research from the Sevilleta LTER.” Jenn’s presentation focused on the potential impacts of changing climate variance, rather than just changes in the mean climate. She talked about some of the underlying theory, gave several examples of recent studies from Sevilleta that help understand the ecological impacts of changing climate variance, and described the new Sevilleta Mean x Variance Experiment, which is being conducted in five different ecosystem types at the LTER. Thanks for your visit, Jenn!

Darby joined a group of Ecoss graduate students and faculty who participated in the Story Collider event at Kitt Recital Hall. The evening was organized as part of the Flagstaff Festival of Science, and was sponsored by NPRs Story Collider podcast and the Writing Class Radio podcast. The presenters, who had spent months developing and polishing their work, bravely shared stories that merged personal lives with science lives, in ways that were emotionally charged, deeply personal, and frequently humorous. After the event, Prof. Jane Marks wrote, “the audience laughed, they gasped, and I think a few shed some tears. It was a beautiful, moving show.” Congratulations, Darby!

For two weeks in September, we had a visit from Johanna Kranz, a PhD student from TU Dresden. Johanna (3rd from left in the back row, below) is working on the PhenoFeedbacks project under the guidance of J. Prof. Dr. Matthias Forkel. Johanna gave a presentation in the Ecoinformatics seminar, and interacted with faculty and students across campus. She also explored many of our local scenic wonders, including Walnut Canyon, the Grand Canyon, Red Mountain, and Sunset Crater. Before leaving town, Jacob and Jen took Johanna to the Lava River Cave northwest of Flagstaff for a below-ground (non-technical) spelunking adventure. Afterwards, Johanna wrote “Visiting Andrew’s lab was a great experience meeting other PhD students and postdocs and learning more about their different areas of research. I look forward to staying in touch and collaborating in the future!” Thank you for your visit, and your kind words, Johanna!

The Logic Supply 2013 AU140 computer (pictured below) that had been the brains of our Bartlett data collection system for over 10 y was recently the subject of a blog post. Check it out!

Congratulations to SICCS T3 Fellowship and NSF GRFP awardee Natasha Wesely, who passed her Comprehensive Exam on September 13. Andrew, Mariah Carbone (Biological Sciences) and David Auty (School of Forestry, and SICCS affiliate) comprised the examination committee. A Building 7 celebration of the successful defense followed later in the day. The picture shows visiting PhD student Johanna Kranz (TU-Dresden), and lab members Mostafa, Jacob, and Natasha all arriving at the off-campus location, where they were joined by a dozen or more additional friends, colleagues, and a few random interlopers and party-crashers.

Although he couldn’t make the installation trip to California, Andrew recently assembled a solar-powered instrument package that includes a data logger, temperature and relative humidity measurements, a PhenoCam and a cell phone modem. George Koch and Drew Peltier hauled the gear to the top of an 80 m. giant Sequoia (Sequoiadendron giganteum) tree near the famed Mariposa Grove in Yosemite National Park. The installation was completed over two days in mid-September. Andrew hopes to visit the site later this autumn. Near-real-time images are available through the PhenoCam web page.

Former Post-Doc Eric Beamesderfer’s paper, “The role of surface energy fluxes in determining mixing layer heights,” has just been published in the AFM special issue on land-atmosphere interactions. Eric’s study used continuous point-based ceilometer- and radiosonde-derived measurements of MLH at surface flux tower sites to identify the surface influence on MLH dynamics. Mean MLH was the highest at all sites during the summer, while the highest annual mean MLH was found at the warm and dry sites, dominated by high sensible heat fluxes. At daily time scales, surface fluxes of sensible heat, latent heat, and vapor pressure deficit had the largest influence on afternoon MLH. These results highlight the difficulty in using single-point observations to explain MLH dynamics but should encourage the use of ceilometers or similar atmospheric measurements at surface flux sites in future studies.