Statistical Ecology Virtual Issue

To celebrate the International Statistical Ecology Conference and British Ecological Society Quantitative Ecology Annual Meeting, Laura Graham and Susan Jarvis have compiled a virtual issue celebrating all things statistical and quantitative in ecology.

Statistical and quantitative methods within ecology have increased substantially in recent years. This rise can be attributed both to the growing need to address global environmental change issues, as well as the increase in data sources to address these challenges. Continue reading

Advertisements

ANDe™: High‐Throughput eDNA Sampling in a Fully Integrated System

Current eDNA sampling technologies consist mainly of do‐it‐yourself solutions. The lack of purpose‐built sampling equipment is limiting the efficiency and standardization of eDNA studies. So, Thomas et al. (a team of molecular ecologists and engineers) designed ANDe™.

In this video, the authors highlight the key features and benefits of ANDe™. This integrated system includes a backpack-portable pump that integrates sensor feedback, a pole extension with remote pump controller, custom‐made filter housings in single‐use packets for each sampling site and on-board sample storage. 

This video is based on the article ‘ANDe: A fully integrated environmental DNA sampling system‘ by Thomas et al.

Issue 9.2

Issue 9.2 is now online!

The February issue of Methods is now online!

This double-size issue contains six Applications articles (one of which is Open Access) and two Open Access research articles. These eight papers are freely available to everyone, no subscription required.

 Temperature Manipulation: Welshofer et al. present a modified International Tundra Experiment (ITEX) chamber design for year-round outdoor use in warming taller-stature plant communities up to 1.5 m tall.This design is a valuable tool for examining the effects of in situ warming on understudied taller-stature plant communities

 ZoonThe disjointed nature of the current species distribution modelling (SDM) research environment hinders evaluation of new methods, synthesis of current knowledge and the dissemination of new methods to SDM users. The zoon R package aims to overcome these problems by providing a modular framework for constructing reproducible SDM workflows.

 BEIN R Package: The Botanical Information and Ecology Network (BIEN) database comprises an unprecedented wealth of cleaned and standardised botanical data. The bien r package allows users to access the multiple types of data in the BIEN database. This represents a significant achievement in biological data integration, cleaning and standardisation.

Continue reading

Imperfect Pathogen Detection: What to Do When Sampling and Diagnostic Tests Produce Inaccurate Results

Post Provided by Graziella DiRenzo

A salamander having its skin swabbed to test for Bsal infection.

A salamander having its skin swabbed to test for Bsal infection.

Imagine you’re at the doctor’s office. You’re waiting to hear back on a critical test result. With recent emerging infectious diseases in human populations, you are worried you may be infected after a sampling trip to a remote field site. The doctor walks in. You sit nervously, sensing a slight tremble in your left leg. The doctor confidently declares, “Well, your tests results came back negative.” In that moment, you let out a sigh of relief, the kind you feel throughout your body. Then, thoughts start flooding your mind. You wonder– what are the rates of false negatives associated with the test? How sensitive is the diagnostic test to low levels of infection? The doctor didn’t sample all of your blood, so how can they be sure I’m not infected? Is the doctor’s conclusion right?

 Now, let’s say I’m the doctor and my patient is an amphibian. I don’t have an office where the amphibian can come in and listen to me explain the diagnosis or the progression of disease − BUT I do regularly test amphibians in the wild for a fatal fungal pathogen, known as Batrachochytrium dendrobatidis (commonly known as Bd). Diseases like Bd are among the leading causes of the approximately one-third of amphibian species that are threatened, near threatened, or vulnerable to extinction. To test for Bd, and the recently emerged sister taxon Batrachochytrium salamandrivorans (hereafter referred to as: Bsal), disease ecologists rely on non-invasive skin swabs. Continue reading

In Vivo Micro-CT Scanning: Studying Reptiles and Amphibians from the Inside Out

POST PROVIDED BY CHRIS BROECKHOVEN, ANTON DU PLESSIS, STEPHAN G. LE ROUX, P. LE FRAS N. MOUTON AND CANG HUI

Lizards, such as these South African armadillo lizards, serve an important role as model organisms for various ecological and evolutionary studies. © Chris Broeckhoven

Lizards, such as these South African armadillo lizards, serve an important role as model organisms for various ecological and evolutionary studies. © Chris Broeckhoven

X-ray micro-computed tomography – or µCT – is a technique that uses x-rays to create high resolution cross-sections of samples. Virtual 3D models can be made from these cross-sections without destroying the original samples. Micro-CT has important applications in medical imaging and, in the biomedical field, in vivo µCT allows researchers to make virtual 3D models of the skeleton and organs of live small animals. Three-dimensional models like these could provide insight into diseases and guide the development of medicines and therapies.

In vivo µCT holds three major advantages over other methods:

  1. It allows for repeated measurements of small live animals at different times without having to sacrifice them.
  2. It eliminates variation among individuals.
  3. It can reduce the number of animals required to obtain statistically meaningful data.

A variety of commercially available µCT scanners that are optimised for scanning live animals are now available. The use of in vivo µCT in ecological and evolutionary studies, however, has greatly lagged behind its use in biomedical studies. Continue reading

Predicting Disease Outbreaks Using Environmental Changes

Below is a press release about the Methods paper ‘Environmental-mechanistic modelling of the impact of global change on human zoonotic disease emergence: a case study of Lassa fever‘ taken from the University College London.

The multimammate rat (Mastomys natalensis) transmits Lassa virus to humans. ©Kelly, et al.

The multimammate rat transmits Lassa virus to humans. ©Kelly, et al.

A model that predicts outbreaks of zoonotic diseases – those originating in livestock or wildlife such as Ebola and Zika – based on changes in climate, population growth and land use has been developed by a UCL-led team of researchers.

“This model is a major improvement in our understanding of the spread of diseases from animals to people. We hope it can be used to help communities prepare and respond to disease outbreaks, as well as to make decisions about environmental change factors that may be within their control,” said lead author Professor Kate Jones, UCL Genetics, Evolution & Environment and the Zoological Society of London. Continue reading

Demography and Big Data

Post provided by BRITTANY TELLER, KRISTIN HULVEY and ELISE GORNISH

Follow Brittany (@BRITTZINATOR) and Elise (@RESTORECAL) on Twitter

To understand how species survive in nature, demographers pair field-collected life history data on survival, growth and reproduction with statistical inference. Demographic approaches have significantly contributed to our understanding of population biology, invasive species dynamics, community ecology, evolutionary biology and much more.

As ecologists begin to ask questions about demography at broader spatial and temporal scales and collect data at higher resolutions, demographic analyses and new statistical methods are likely to shed even more light on important ecological mechanisms.

Population Processes

Midsummer Opuntia cactus in eastern Idaho, USA. © B. Teller.

Midsummer Opuntia cactus in eastern Idaho, USA. © B. Teller.

Traditionally, demographers collect life history data on species in the field under one or more environmental conditions. This approach has significantly improved our understanding of basic biological processes. For example, rosette size is a significant predictor of survival for plants like wild teasel (Werner 1975 – links to all articles are at the end of the post), and desert annual plants hedge their bets against poor years by optimizing germination strategies (Gremer & Venable 2014).

Demographers also include temporal and spatial variability in their models to help make realistic predictions of population dynamics. We now know that temporal variability in carrying capacity dramatically improves population growth rates for perennial grasses and provides a better fit to data than models with varying growth rates because of this (Fowler & Pease 2010). Moreover, spatial heterogeneity and environmental stochasticity have similar consequences for plant populations (Crone 2016). Continue reading

New Associate Editors

Today we are welcoming three new Associate Editors to Methods in Ecology and Evolution: Nick Golding (University of Melbourne, Australia), Rachel McCrea (University of Kent, UK) and Francesca Parrini (University of the Witwatersrand, South Africa). They have all joined on a three-year term and you can find out more about them below.

Nick Golding

Nick Golding

Nick Golding

“I develop statistical models and software for mapping the distributions of species and diseases. I’m particularly interested in tools that make it easy for researchers to add more mechanistic structure into their correlative models (and vice versa) so that they can use all available information when making predictions. I also develop software and other tools to bring research communities together and help them advance ecology by enabling and incentivising reproducible and extensible research.”

Nick has recently had an article published in Methods in Ecology and Evolution (currently in Early View). In ‘Fast and flexible Bayesian species distribution modelling using Gaussian processes‘ Nick and his co-author (Bethan Purse) introduce Gaussian process (GP) models and their application to species distribution modelling (SDM), illustrate how ecological knowledge can be incorporated into GP SDMs via Bayesian priors and formulate a simple GP SDM that can be fitted efficiently. The article is Open Access, so it’s freely available to everyone.

Rachel McCrea

Rachel McCrea

Rachel McCrea

“I am a NERC research fellow and lecturer in statistics at the University of Kent.  My particular areas of interest include capture-recapture modelling, multistate models, modelling population dynamics and methods of model assessment.  My research is motivated by interesting discussions with ecologists and I strive to find innovative, but practical statistical solutions to ecological questions.”

Rachel is one of the authors of Analysis of Capture-Recapture Data (along with Byron Morgan). The book covers the many modern developments of capture-recapture (and related) methods and will be of interest to researchers and graduate students in statistics, ecology and demography. It contains 130 exercises designed to complement and extend the text and help readers to assimilate the material.

Francesca Parrini

Francesca Parrini

Francesca Parrini

“My broad research interests lie in the ecology and behaviour of mammalian herbivores, their interaction with biotic and abiotic factors and the integration of factors governing decisions at the small foraging scale and factors governing decisions at the landscape level. As such, my research lies at the interface of remote sensing, behavioural ecology and conservation. Recently I have become interested in the application of graph theory and network analysis to ecological settings, in particular to study the spatio-temporal structure of animal movement patterns.”

Last year Francesca had her article (co-authored with Maria Miranda) ‘Congruence between species phylogenetic and trophic distinctiveness‘ published in Biodiversity and Conservation. In this paper the authors investigate the relationship between species’ phylogenetic history and patterns of resource use. They show that there is congruence between species phylogenetics and interaction distinctiveness and propose that this relationship could provide a possible novel approach to the conservation of ecosystem diversity.

We are thrilled to welcome Nick, Rachel and Francesca to the Associate Editor Board and we look forward to working with them over the coming years.