Advancing trophic position estimation: from bulk isotope models to CSIA-AA using the tRophicPosition R package

Dr. Claudio Quezada-Romegialli

Date: 11 October 2026
Capacity: 25 People

Stable isotope analysis has become a cornerstone for quantifying trophic position (TP) in ecological studies, yet methodological choices—ranging from baseline selection to model structure—can substantially influence inference. This workshop provides a hands-on introduction to the R package tRophicPosition, with a strong emphasis on statistical formulation and model implementation across multiple levels of biological organization.We begin by revisiting classical bulk isotope approaches, including one- and two-baseline models, and their formalization under the framework proposed Post (2002). Participants will implement these models using Bayesian inference, exploring parameter sensitivity, uncertainty propagation, and baseline variability at the population level. The workshop then advances to individual-level modelling, introducing hierarchical structures that explicitly account for within-population variability in isotopic signatures. We will discuss likelihood specification at the individual level and demonstrate how this formulation improves inference in heterogeneous systems. A key component of the workshop is the extension to multi-baseline models (>2 baselines), addressing complex food webs where traditional assumptions are violated. Participants will learn how to parameterize and interpret these models within tRophicPosition. Finally, we introduce a new implementation of compound-specific isotope analysis of amino acids (CSIA-AA), based on recent developments extending this framework. This section will cover the integration of amino acid-specific δ¹⁵N data, model structure, and practical application using real and modelled datasets. The workshop is designed for participants with basic to intermediate R skills and will combine conceptual explanations with guided coding exercises. Attendees are expected to bring their own laptops.
Funding: ANID CIN250047

Strontium isotope geolocation for terrestrial ecology

Dr. Clement Bataille, Dr. Megan Reich, Dr. Chris Stantis

Date: 11 October 2026
Capacity: 25 People

This workshop introduces participants to the theory, methodology, and practical implementation of strontium isotope geolocation for terrestrial ecological research. Using the newly published ARDUOUS global database of bioavailable strontium, participants will learn how to construct isotopic basemaps, evaluate the spatial predictability of 87Sr/86Sr, and perform geographic assignments using real ecological case studies. The workshop combines lectures, guided discussions, and extensive hands on R practice. Participants will learn how to select and preprocess environmental samples from the ARDUOUS database and then develop a modern strontium isoscape using random forest regression with covariates. The workshop will also focus on refining isoscape performance and performing geographic assignments, including evaluation of uncertainty, spatial bias, and limitations of strontium based provenance tools. By the end of the workshop, participants will be able to:

• Query and filter bioavailable strontium datasets appropriate for their system of interest
• Build reproducible strontium isoscapes using machine learning methods in R
• Interpret spatial patterns in 87Sr/86Sr and understand geologic and environmental drivers
• Perform geolocation assignments for organisms of unknown origin
• Critically evaluate the assumptions, limitations, and best practices of strontium based ecological inference

This workshop is designed for ecologists, conservation biologists, archaeologists, and geochemists interested in applying isotopic provenance methods to wildlife movement, migration, and landscape level ecological studies.

Pre-Conference Workshop: Understanding Stable Isotope Ecology

Dr. Brian Hayden

Date: 11 October 2026
Capacity: 25 People

Designed for students and early-career researchers entering the field, this intensive pre-conference workshop provides a clear, practical introduction to stable isotope ecology ahead of the IsoEcol 2026 Conference. The goal is to give participants a strong conceptual and applied foundation so they can confidently engage with presentations, posters, and discussions throughout the meeting. Stable isotopes are powerful tracers of ecological processes, widely used to investigate diet, food web structure, movement, and nutrient pathways. However, many new users arrive at conferences without formal training in the underlying principles, making it difficult to fully interpret what they see. This workshop bridges that gap by combining accessible theory with applied examples and hands-on laboratory context.

The course begins with a structured introduction to the fundamentals of isotope chemistry, including isotopic variation, delta notation, and fractionation processes. These concepts are then explored within the context of natural systems, with a focus on how carbon and nitrogen isotopes move through biogeochemical cycles and how this variation underpins ecological applications. Building on this foundation, the workshop examines how isotopes are used to address key ecological questions. Topics include quantifying resource use in food webs (e.g., benthic vs pelagic pathways), estimating trophic position, understanding dietary variation and niche width, and using isotopes to infer movement and geographic origin through spatial patterns in isotopic baselines. The workshop also introduces compound-specific isotope analysis (CSIA) of amino acids, an increasingly important approach in modern isotope ecology. Participants will gain an overview of how δ¹⁵N values of amino acids can be used to estimate trophic position with improved precision, and how δ¹³C values of essential amino acids can be applied to trace primary production sources and resolve complex food web pathways. The strengths, limitations, and practical considerations of CSIA approaches will be discussed in the context of real-world applications. A core component of the workshop is an introduction to laboratory workflows. Participants will be guided through the key steps of sample preparation, including tissue selection, drying, homogenisation, and preparation for isotope ratio mass spectrometry (IRMS). Emphasis will be placed on best practices, quality control, and common pitfalls that can compromise data quality. The final component focuses on interpretation. Using real-world examples, participants will learn how isotope data are visualised (e.g., biplots) and how to translate patterns into ecological insight, while recognising the limitations and assumptions inherent in isotope-based approaches. By the end of the workshop, participants will be able to design basic isotope studies, identify appropriate sampling strategies, and critically interpret isotope data in an ecological context. This workshop is ideal preparation for anyone looking to maximise the value of their experience at IsoEcol 2026 and to build confidence as a new user of stable isotope techniques.

Price: €100.00