Highlights from the Andrews Forest Program are listed below. Also see "LTER Transformative Science" for a list of important contributions to ecological science from the Andrews Forest program, compiled at the request of the National Science Foundation.
Hydrologic and biogeochemical controls of carbon flux
Researchers will be studying how carbon is processed, exported, and stored within headwater streams of the westetn Oregon Cascasde mountains, using the Andrews Forest as a primary field site. Roy Haggerty and Steve Wondzell will lead the project, funded by a grant from the National Foundation. Their work on how hydrology and biogeochemistry interact to control carbon in headwater streams will help scientists understand the role of streams in the global carbon budget. [Read More...]
Story Map Dashboard of Webcams and Streaming Data
A Simple Story Map-based Real-Time Dashboard for the H.J. Andrews Experimental Forest. (new post in GIS and Science gisandscience.com/ )
As a charter member of the National Science Foundation’s Long-Term Ecological Research (LTER) Program, the site contributes to the collection of long-term datasets to support research on ecological issues that can last decades. Using Esri’s story maps technology, a simple map-based dashboard was developed to let researchers, administrators, and the general public view real-time data from 125 different sensors including webcams, stream gauges, and weather stations deployed throughout the forest.
Large, old trees fix more carbon than younger trees
Long-term vegetation study plots at the Andrews Forest were part of a global analysis that showed that growth rate increased continuously with tree size and that large, old trees fix large amounts of carbon compared to smaller trees. These findings go against a widely-held assumption that after an initial period of increasing growth, the mass growth rate of individual trees declines with increasing tree size.
The full study, which appears in the journal, Nature, can be found at www.nature.com/nature/journal/vaop/ncurrent/full/nature12914.html
Stephenson, N. L., A. J. Das, R. Condit, S. E. Russo, P. J. Baker, N. G. Beckman, D. A. Coomes, E. R. Lines, W. K. Morris, N. Rüger, E. Álvarez, C. Blundo, S. Bunyavejchewin, G. Chuyong, S. J. Davies, á. Duque, C. N. Ewango, O. Flores, J. F. Franklin, H. R. Grau, Z. Hao, M. E. Harmon, S. P. Hubbell, D. Kenfack, Y. Lin, J.-R. Makana, A. Malizia, L. R. Malizia, R. J. Pabst, N. Pongpattananurak, S.-H. Su, I.-F. Sun, S. Tan, D. Thomas, P. J. van Mantgem, X. Wang, S. K. Wiser, and M. A. Zavala. 2014. Rate of tree carbon accumulation increases continuously with tree size. Nature.
Studying 50 Years of Vegetation Change
The abundant herb and shrub communities that develop after disturbances, such as logging or burning, are drawing increasing attention as critical habitats for many invertebrates, birds, and other animals. Permanent vegetation plots established by Ted Dyrness in 1962, in two clearcut and burned watersheds of the Andrews Forest, provide the longest, most detailed records of changes in understory vegetation as these systems revert to closed-canopy forests. In a recent publication, Charlie Halpern (University of Washington) and Jim Lutz (Utah State) observed that over three decades of measurement in Watersheds 1 and 3, tree cover increased fourfold, and biomass more than two orders of magnitude. Surprisingly, during the same period, understory species richness and cover declined an average of only 30-40% and, in many plots, there was no evidence of a decline. For plots that declined in richness or cover, the decrease was largely attributable to loss of early-seral species, such as fireweed and ceanothus, that established soon after disturbance. In contrast, forest understory species that survived disturbance, persisted despite closure of the tree canopy. These findings run counter to a common perception that trees exert strong controls on understory vegetation during canopy closure. They also highlight the importance of long-term studies for elucidating patterns and processes that cannot be understood from short-term experiments or space-for-time substitutions.
The paper, "Canopy closure exerts weak controls on understory dynamics: a 30-year study of overstory-understory interactions" was published in Ecological Monographs, 83(2), 2013, pp 221-237.
As data flow, scientists advocate for quality control
As sensor networks revolutionize ecological data collection by making it possible to collect high frequency information from remote areas in real time, scientists with the U.S. Forest Service are advocating for automated quality control and quality assurance standards that will make that data reliable.
In an article published recently in the journal Bioscience, research ecologists John Campbell and Lindsey Rustad of the U.S. Forest Service's Northern Research Station and colleagues make a case for incorporating automated quality control and quality assurance procedures in sensor networks. The article, "Quantity is Nothing without Quality: Automated QA/QC for Streaming Environmental Sensor Data," is available at: http://www.nrs.fs.fed.us/pubs/43678
Note that Don Henshaw from the Andrews LTER is a co-author on the publication.
Researchers Track Arrival of Spring
Researchers at the Andrews Forest are tracking the arrival of spring by watching bud break in native plants. Phenocams, weather-proof cameras positioned in the field, help researchers track bud break over a wide area at a daily interval. They also can help scale up from ground observations to monitoring through satellite imagery. Comparisons of the timing of bud break from site to site and year to year can tell scientists about microclimate drivers and trends over time. Phenology observations across trophic levels may help us understand more about the effects of climate change on ecosystems. More information on this project at the Andrews Forest can be found on our Phenology pages (http://andrewsforest.oregonstate.edu/research/lter6/current.cfm?pid=55&topnav=244)
Nitrogen Trends in Reference Watersheds
A cross-site collaborative study from the Andrews Forest and seven other Experimental Forests (4 of which are LTER sites) compared water quality trends in forested streams across the country that are largely undisturbed by land use or land cover changes.
The researchers analyzed 559 years of stream nitrate and 523 years of stream ammonium data from 22 streams in 7 experimental forests across the country. They found that even these near-pristine forested streams are subject to change, as stream nitrate has declined in the Pacific Northwest, in the Northeast, and in Puerto Rico, but has increased in the Mountain West and the South. They also observed that, within a forest, trends were not always in sync—at some sites, two streams within an experimental forest had opposing trends for the same type of nitrogen for the same period of time, suggesting that the controls on stream nitrogen concentrations may vary among and within sites.
The study's findings are summarized in an online video available at http://iopscience.iop.org/1748-9326/8/1/014039
The work was also recently featured in Phys.Org: http://phys.org/news/2013-03-explores-long-term-quality-trends-near-pristine.html
Andrews Forest Children's Book, Ellie's Log
"Ellie's Log, Exploring the Forest Where the Great Tree Fell" by Judith L. Li. Illustrations by M. L. Herring.
Ages 9-12 (Grades 4-6). Companion Teacher's Guide. Color Illustrations. 112 pages.
Publication date April 1, 2013
After a huge tree crashes to the ground during a winter storm, ten-year-old Ellie and her new friend, Ricky, explore the forest where Ellie lives. Together, they learn how trees provide habitat for plants and animals high in the forest canopy, down among mossy old logs, and deep in the pools of a stream. The plants, insects, birds, and mammals they discover come to life in colored pen-and-ink drawings.
The forest and animals described in Ellie's Log are based on those found at the H. J. Andrews Experimental Forest.
An engaging blend of science and storytelling, Ellie’s Log also features:
• Pages from Ellie’s own field notebook, which provide a model for recording observations in nature
• Ellie’s advice to readers for keeping a field notebook
• Ellie's book recommendations
• Online resources for readers and teachers—including a Teacher’s Guide—are available at www.ellieslog.org.
See the Ellie's Log Trailer