TAKE OUR SURVEY!!

Greetings uncertainty enthusiasts,

As part of the QUEST workshop at this summer’s LTER All Scientists Meeting, we developed a brief survey to assess practices in reporting uncertainty in precipitation, streamflow, biomass, and soils. We are extending it to all researchers working in these areas. All four sections need not be filled out by the same individual.

The survey can be taken here: https://www.surveymonkey.com/r/EcosytemUncertainty

We’re asking that respondents complete the survey within two weeks. Each section takes an estimated 5-10 minutes.  Please feel free to pass this on to other researchers at your site or at other sites.

To express our appreciation, one respondent will be randomly selected to receive QUEST support of a publication that reports uncertainty, in the form of payment for Open Access publication. 

We plan to report the results in a review article on uncertainty analysis.

QUEST Workshop at the LTER All Scientists Meeting a Success

Last week QUEST held a working group at the LTER ASM in Estes Park, CO, titled “Sources of Uncertainty in Ecosystem Monitoring.”  The first hour of the working group consisted of six brief presentations on different aspects of uncertainty in ecosystem monitoring, each followed by a similar lightning round discussion. The second hour consisted of a longer group discussion, and at the end participants were invited to take a survey on how they deal with uncertainty in their own research. We received positive feedback from many participants, and plan to use the results of the survey as part of a review article on current practices for uncertainty in ecosystem ecology.

List of presenters:

·        Ruth Yanai (SUNY-ESF): A brief history of QUEST; Uncertainty in the Hubbard Brook nitrogen budget

·        Craig See (University of Georgia): Gaps: why they occur, and what we can do about them.

·        John Campbell (USFS): Uncertainty in the net hydrologic flux of calcium in a paired-watershed harvesting study.

·        Josh Roberti (NEON): Connecting uncertainty estimates and QA/QC methods.

·        Melissa Slater (NEON): Examining spatial patterns of precipitation in complex terrain.

·        Carrie Levine (UC Berkeley): Using Bayesian hierarchical models to estimate forest demographic processes.

QUEST Special Issue of Canadian Journal of Forest Research

We are pleased to announce a special issue of CJFR titled: Quantifying uncertainty in forest measurements and models: Approaches and applications. Many of the papers in this issue will be based on the research presented in the QUEST sessions at the 2014 IUFRO world congress in Salt Lake City, but we encourage the submission of any relevant papers.

The deadline for submissions is April 15, 2015.  The Online First technology allows for immediate online publication after acceptance, so the paper can be cited before the issue appears in print (Fall 2015).

CJFR is published by NRC Research Press, a non for profit organization. Instruction for Authors can be found at: http://www.nrcresearchpress.com/page/cjfr/authors

During submission you will be asked if the paper is for a special issue. Please respond yes, and when prompted by Scholar One, provide the issue name “Quantifying uncertainty in forest measurements and models: Approaches and applications”. Please also mention the special issue in your cover letter. 

IUFRO 2014 Now in Session!

This week, Salt Lake City, Utah,  hosts the world's largest forest research conference with the co-located 24th IUFRO World Congress and joint annual conventions of the Society of American Foresters (SAF) and the Canadian Institute of Forestry/Canadian Institute of Forestry/l’Institut forestier du Canada (CIF/IFC).

Please visit QUEST’s subplenary session today, 1:30- 3 pm, SP-07 The Importance of quantifying uncertainty in managing forests in 251 A-C; our Side Event:  Practical Issues in Implementing Uncertainty Analysis, Thurs 7-9 pm, in Room 150D; and the technical sessions  C-12 Quantifying  Uncertainty in Forest Measurements and Models:  Approaches and Applications, this Friday, October 10, 2014, 8-10:30 in 250 F, and continuing 3:30-6 pm, again in 250F.

Many of these IUFRO talks will be later published in a special issue of the Canadian Journal of Forest Research.  Space permitting, the editors can consider additional manuscripts.  Stay tuned for submission information.

Meanwhile, our neighbors at the SAF/CIF/IFC Convention offer these related tracks:  

• An Engineering Take on Uncertainty:  Lessons for the Forestry Profession  Thurs., October 9, 1:30- 3 PM and 4 - 5:30 PM in 355 D
• Embracing, and Learning from, Uncertainty, Thurs., October 9, 2014, 1:30 PM - 3:00 PM and 4-6 pm, in 255E, and Saturday, Oct 11, 10:30-12, in 255D.

To help navigate the meetings, use the SAF2014 and/or IUFRO2014 apps.  If you would like to stay in the loop regarding that special CJFR issue, ask us about the QUEST mailing list.  

Early View! Sources of uncertainty in estimating stream solute export from three headwater catchments

Yanai, R.D., N. Tokuchi, J.L. Campbell, M.B. Green, E. Matsuzaki, S.N. Laseter, C.L. Brown, A.S. Bailey, P. Lyons, C.R. Levine, D.C. Buso, G.E. Likens, J. Knoepp, K. Fukushima. 2014. Hydrological Processes.

Uncertainty in the estimation of hydrologic export of solutes has never been fully evaluated at the scale of a small-watershed ecosystem. We used data from the Gomadansan Experimental Forest, Japan, Hubbard Brook Experimental Forest, USA, and Coweeta Hydrologic Laboratory, USA, to evaluate many sources of uncertainty, including the precision and accuracy of measurements, selection of models, and spatial and temporal variation. Uncertainty in the analysis of stream chemistry samples was generally small but could be large in relative terms for solutes near detection limits, as is common for ammonium and phosphate in forested catchments. Instantaneous flow deviated from the theoretical curve relating height to discharge by up to 10% at Hubbard Brook, but the resulting corrections to the theoretical curve generally amounted to <0.5% of annual flows. Calibrations were limited to low flows; uncertainties at high flows were not evaluated because of the difficulties in performing calibrations during events. However, high flows likely contribute more uncertainty to annual flows because of the greater volume of water that is exported during these events. Uncertainty in catchment area was as much as 5%, based on a comparison of digital elevation maps with ground surveys. Three different interpolation methods are used at the three sites to combine periodic chemistry samples with streamflow to calculate fluxes. The three methods differed by <5% in annual export calculations for calcium, but up to 12% for nitrate exports, when applied to a stream at Hubbard Brook for 1997–2008; nitrate has higher weekly variation at this site. Natural variation was larger than most other sources of uncertainty. Specifically, coefficients of variation across streams or across years, within site, for runoff and weighted annual concentrations of calcium, magnesium, potassium, sodium, sulphate, chloride, and silicate ranged from 5 to 50% and were even higher for nitrate. Uncertainty analysis can be used to guide efforts to improve confidence in estimated stream fluxes and also to optimize design of monitoring programs.

This work is supported by the National Science Foundation (NSF) and the NSF Long-Term Ecological Research (LTER) Network Office. Many of the ideas implemented in this paper were developed in a meeting of a QUEST Working Group in March 2011. In June 2011, the Japanese Society for the Promotion of Science (JSPS) awarded a fellowship to Ruth Yanai, hosted by Naoko Tokuchi, to work on this project. The research at Gomadansan is supported by the staff of the Wakayama Experimental Forest of Kyoto University. The Hubbard Brook Experimental Forest is operated by the US Forest Service and the Hubbard Brook Research Foundation, and it forms part of the NSF LTER site network. Research at Coweeta Hydrologic Laboratory was funded by the US Forest Service, Department of Agriculture, Southern Research Station, and the NSF LTER (DEB-9632854 and DEB-0218001). Chemistry data for HBEF were obtained through funding from The A.W. Mellon Foundation and the NSF, including the LTER and LTREB programs.

Early View and Open Access! A climate of uncertainty: accounting for error in climate variables for species distribution models

Stoklosa, J., Daly, C., Foster, S. D., Ashcroft, M. B., Warton, D. I. (2014), A climate of uncertainty:
accounting for error in climate variables for species distribution models. Methods in Ecology and Evolution. doi: 10.1111/2041-210X.12217

The authors summarize:

1. Spatial climate variables are routinely used in species distribution models (SDMs) without accounting for the fact that they have been predicted with uncertainty, which can lead to biased estimates, erroneous inference and poor performances when predicting to new settings – for example under climate change scenarios.
2. We show how information on uncertainty associated with spatial climate variables can be obtained from climate data models. We then explain different types of uncertainty (i.e. classical and Berkson error) and use two statistical methods that incorporate uncertainty in climate variables into SDMs by means of (i) hierarchical modelling and (ii) simulation–extrapolation.
3. We used simulation to study the consequences of failure to account for measurement error. When uncertainty in explanatory variables was not accounted for, we found that coefficient estimates were biased and the SDM had a loss of statistical power. Further, this bias led to biased predictions when projecting change in distribution under climate change scenarios. The proposed errors-in-variables methods were less sensitive to these issues.
4. We also fit the proposed models to real data (presence/absence data on the Carolina wren, Thryothorus ludovicianus), as a function of temperature variables.
5. The proposed framework allows for many possible extensions and improvements to SDMs. If information on the uncertainty of spatial climate variables is available to researchers, we recommend the following: (i) first identify the type of uncertainty; (ii) consider whether any spatial autocorrelation or independence assumptions are required; and (iii) attempt to incorporate the uncertainty into the SDM through established statistical methods and their extensions.

Workshop: Tools for Estimating Uncertainty in Ecology

August 10, 2014, Ecological Society Annual Meeting, Sacremento, CA. 

Although methods are well established for statistical analysis of most experimental designs, there are fields in Ecology where it is more difficult to establish confidence in results (e.g., in catchment studies, treatments are rarely replicated).   For environmental networks, using standardized approaches ensures that results are comparable, but sometimes the same statistical technique is not applicable to comparable data sets (e.g. when there are significant differences in the sample size of the same population at two geographically distinct locations).   Many of these concerns can be addressed through the appropriate use of tools for uncertainty analysis. This workshop will highlight current developments in uncertainty estimation across many fields of ecology.   Overview presentations will focus on practical examples of how uncertainty calculations can inform data over small-to-large scales.   Data packages and software tools will be shared with the attendees.  Participants are encouraged to bring their own data sets and laptop computers; we will provide data for the exercises if you don’t bring your own.   Organizers Jeffrey R. Taylor, Ruth D. Yanai and John Campbell, and moderator Jeffrey R. Taylor welcome participation by researchers in all career stages and from a broad array of ecological disciplines.