Lab News

Publications abound in the Battles lab this fall! Here are some recent research papers from graduate students:

• From a diverse research team including Carrie Levine, this new paper evaluates uncertainty in hydrologic export of solutes in three watersheds: in the Northeast and Southeast US and in the Gomadansan Experimental Forest, Japan. Read Article

• Natalie van Doorn’s recent participation in a research team examining environmental chemistry using Scots pine has yielded two publications. The first, in Science of Total Environment, examines bioaccumulation of heavy metals from mine soils. The second, in New Forests, uses Scots pine growth to assess productivity of reclaimed forest sites.
  Read Article in Science of Total Environment 
  Read Article in New Forests

• And in new paper Simon Dufour, Maya Hayden and their collaborators ask, “Do abandoned channels host different plant species compared with the surrounding floodplain?” The study, now out in Ecohydrology, investigates vegetation community and disturbance dynamics along riparian forest gradients. Read Article

At the annual symposium of the California Invasive Plant Council in Chico, Joan Dudney presented her research on the lagged effects of rainfall on rangeland plant community composition. Results suggest that native plants may fare better in grazed grasslands under increasing drought conditions, but forage production is apt to suffer. Joan also earned an award for her talk – congrats to Joan!

At the joint meeting of the International Union of Forest Research Organizations and the Society of American Foresters in Salt Lake City, Stella Cousins gave a research presentation entitled “Improving estimates of carbon dynamics for snags in the Sierra Nevada range.” She also gave a lightning talk on ozone impacts in Sequoia and Kings Canyon National Parks, and enjoyed a bit of fall color, thanks to the aspens and maples in the Wasatch Range.

Congratulations to Stella Cousins who continues to shine as a scientist and communicator. She received an inaugural award in the Graduate Training in Cooperative Extension Program to support her work to bring the forest into the classroom. She also successfully competed for a grant from the Renewable Resources Extension Act to expand her smartphone microscope project. Stella’s work with Cooperative Extension and the Forestry Institute for Teachers was recently featured in ESPM’s departmental blog.

More information can be found on the Graduate Training in Cooperative Extension Program website.

Ecologists past, present, and future descended on Sacramento in August for the 99th meeting of the Ecological Society of America. We were glad to see colleagues from near and far, and also to share our work in progress with lots of talks.  Carrie Levine shared Stand demography as an indicator of ecological resilience in an old-growth mixed conifer forest (ABSTRACT ). Maya Hayden presented Pioneer riparian tree seedling establishment in floodplain refugia is driven by interspecific competition in addition to water availability (ABSTRACT). Meanwhile, on the other side of the convention center, Stella Cousins presented Trees in transition: the role of standing dead trees in forest carbon dynamics with many thanks to incomparable coauthor John Sanders (ABSTRACT). But that’s not all: Joan Dudney also gave a great poster on Precipitation effects on plant composition in California rangelands (ABSTRACT) and John shared his and Natalie’s research in Understanding neighborhood effects on growth and competition in a temperate forest (ABSTRACT). Well done, everyone!

Does the costly work of reducing wildfire risk with fuel treatments have hidden benefits? And can we measure them? Following a series of workshops on forest health and management held at Blodgett Forest Research Station, the Placer County Air Pollution Control District has produced ashort video that summarizes pertinent observations, research, and recommendations. A diverse group of resource professionals, researchers, state/federal agency representatives, utility representatives and elected officials, including our very own Rob York and John Battles, provide thoughtful and candid comments.

Watch the video

In a recent paper (Ecological Impacts, Vol. 39, pp. 94-101), Carrie Levine and colleagues describe methods for analyzing long-term monitoring data to evaluate whether current monitoring programs are as efficient and effective as possible. This can allow researchers to maximize information gained relative to resources required for data collection. In the paper, the authors describe methods for analyzing data from four types of monitoring schemes: long-term records from a single site, one-time surveys at multiple sites, plot-level sampling, and time-series data from multiple sites. Evaluating long-term monitoring data at regular intervals throughout the monitoring program can help researchers determine whether sampling should be reallocated in space or time to optimize the use of financial and human resources.

Read the full article

In Reconstructing Disturbances and Their Biogeochemical Consequences over Multiple Timescales, Kendra McLauchlan and colleagues, including John Battles, overview how disturbances are reconstructed using natural records. Here is the abstract:

Ongoing changes in disturbance regimes are predicted to cause acute changes in ecosystem structure and function in the coming decades, but many aspects of these predictions are uncertain. A key challenge is to improve the predictability of postdisturbance biogeochemical trajectories at the ecosystem level. Ecosystem ecologists and paleoecologists have generated complementary data sets about disturbance (type, severity, frequency) and ecosystem response (net primary productivity, nutrient cycling) spanning decadal to millennial timescales. Here, we take the first steps toward a full integration of these data sets by reviewing how disturbances are reconstructed using dendrochronological and sedimentary archives and by summarizing the conceptual frameworks for carbon, nitrogen, and hydrologic responses to disturbances. Key research priorities include further development of paleoecological techniques that reconstruct both disturbances and terrestrial ecosystem dynamics. In addition, mechanistic detail from disturbance experiments, long-term observations, and chronosequences can help increase the understanding of ecosystem resilience.

Read the full article at BioScience

Acid deposition has depleted calcium in forest soils throughout the northeastern US, a pattern tied to forest declines in the region. But through a fifteen year experiment at Hubbard Brook Experimental Forest that restores this lost calcium, John Battles and colleagues have shown that forests can recover from the damaging impacts of acid rain. The study compares forest growth and productivity in a pair of watersheds. The experimental addition of more than 40 tons of calcium silicate to one watershed allowed comparison of the forests’ responses: the restored forest showed higher aboveground NPP, increased photosynthetic surface area, and a rebound in tree biomass increment. It was also faster to recover from a severe ice storm that affected the area in 1998.

• Read the article in Environmental Science and Technology Letters
  
• Read this article on the UC Berkeley News Service

A big “Thank you!” goes out to our summer research assistants, Natalie Holt and Alex Javier. From May through August Natalie and Alex lent their talents to our research crew, completing lab projects throughout the Sierra Nevada at Baker Forest, Blodgett Forest Research Station, and in Sequoia National Park. Leading the work were Carrie Levine, Flora Krivak-Tetley, and Stella Cousins. Joe Battles was also a big help during our studies at Blodgett. Together we measured thousands of trees, mapped forest plots, built snazzy seed traps, dissected snags, compared swimming holes, and much, much, more. Thanks to everyone involved for the hard work! This summer’s efforts are sure to keep us busy for months (years?) to come.

In the latest issue of the Journal of Forestry (Vol 110, Issue 8, pg. 448-456), Ruth Yanai, Carrie Levine, Mark Green, and John Campbell describe methods for quantifying uncertainties in forest nutrient pools and fluxes. Nutrient budgets of forest ecosystems have not historically included error analysis, in spite of the importance of uncertainty to interpretation and extrapolation of the results. Uncertainty in ecosystem budgets derives from natural variability, such as spatial and temporal uncertainty, as well as knowledge uncertainty, such as model and analytical errors. For example, in the case of nutrient content of forest biomass, the overall uncertainty would be comprised of measurement uncertainty (variation between plots), analytic uncertainty (detection limits of analytical instruments), within-model uncertainty (error in allometric equations), and between-model uncertainty (choosing which allometric equations to use). This paper uses the Hubbard Brook Experimental Forest as an example and describes approaches for quantifying uncertainty in biomass, soils, and hydrologic inputs and outputs. The results suggest that change over time may have less uncertainty than a single measurement if the measures are consistently biased, for example the use of inaccurate allometric equations or soil sampling techniques. These methods can be adapted to many other ecosystems and can have important forest management applications. Identifying the largest uncertainties in nutrient budgets allows us to direct research efforts where the need for information is greatest.