Issue 8.7

Issue 8.7 is now online!

© Paula Matos

The July issue of Methods is now online!

This issue contains three Applications articles (one of which is Open Access) and one additional Open Access article. These four papers are freely available to everyone, no subscription required.

BioEnergeticFoodWebs: An implementation of Yodzis & Innes bio-energetic model, in the high-performance computing language Julia. This package can be used to conduct numerical experiments in a reproducible and standard way.

 Controlled plant crosses: Chambers which allow you to control pollen movement and paternity of offspring using unpollinated isolated plants and microsatellite markers for parents and their putative offspring. This system has per plant costs and efficacy superior to pollen bags used in past studies of wind-pollinated plants.

 The Global Pollen Project: The study of fossil and modern pollen assemblages provides essential information about vegetation dynamics in space and time. In this Open Access Applications article, Martin and Harvey present a new online tool – the Global Pollen Project – which aims to enable people to share and identify pollen grains. Through this, it will create an open, free and accessible reference library for pollen identification. The database currently holds information for over 1500 species, from Europe, the Americas and Asia. As the collection grows, we envision easier pollen identification, and greater use of the database for novel research on pollen morphology and other characteristics, especially when linked to other palaeoecological databases, such as Neotoma.

Continue reading

Bottom-up Citizen Science and Biodiversity Statistics

Post provided by Ditch Townsend and Robert Colwell

Different Paths to Science

Ditch Townsend on Exmoor in Devon, UK

Ditch Townsend on Exmoor in Devon, UK

DITCH: Amateur naturalists from the UK have a distinguished pedigree, from Henry Walter Bates and Marianne North, to Alfred Russel Wallace and Mary Anning. But arguably, the rise of post-war academia in the fifties displaced them from mainstream scientific discourse and discovery. Recently, there has been a resurgence of the ‘citizen scientist’, like me, in the UK and elsewhere – although the term may refer to more than one kind of beast.

To me, the ‘citizen scientist’ label feels a little patronising – conveying an image of people co-opted en masse for top-down, scientist-led, large-scale biological surveys. That said, scientist-led surveys can offer valid contributions to conservation and the documentation of the effects of climate change (among other objectives). They also engage the public (not least children) in science, although volunteers usually have an interest in natural history and science already. For me though, the real excitement comes in following a bottom-up path: making my own discoveries and approaching scientists for assistance with my projects.

Robert Colwell at the Boreas Pass in Colorado, USA

Robert Colwell at the Boreas Pass in Colorado, USA

ROB: I grew up on a working ranch in the Colorado mountains, surrounded on three sides by National Forest and a National Wilderness Area. My mother, an ardent amateur naturalist, taught me and my sister the local native flora and fauna and our father instilled a respect for the land in us. For my doctoral research at the University of Michigan, I studied insect biodiversity in Colorado and Costa Rica at several elevations. The challenges of estimating the number of species (species richness) and understanding why some places are species-rich and others species-poor has fascinated me ever since. Continue reading

The Right Tool for the Job: Using Zeta Diversity to Communicate Uncertainty in Ecological Modelling

Post provided by Mariona Roigé

The Need for Modelling

Green vegetable bug nymph (Nezara viridula). ©John Marris. Lincoln University.

Green vegetable bug nymph (Nezara viridula). ©John Marris. Lincoln University.

Despite how far modelling has taken us in science, the use of models remains controversial. Modelling covers a huge range of common practices, from scaled models of ships to determine the shape that will have the least resistance to water to complex, comprehensive ‘models of everything’. A great example of the latter is the Earth System Model. This model aims to understand the changes in global climate by taking into account the interaction between physical climate, biosphere, the atmosphere and the oceans. Basically, a model of how the Earth works.

The controversy in the use of modelling resides in how accurately the model describes reality and the level of confidence we have in its outputs. The first argument can be a bit counter-intuitive: sometimes, a very simple model can be a great predictor. Actually, the conventional view in ecology is that simple models are more generalisable than complex models, although this view is being challenged. However, the level of confidence, or the level of uncertainty, that we have in the outputs of the model is a crucial point. We need to be able to accurately determine our levels of uncertainty if we want people to trust our models. Continue reading

Fast-Moving Biodiversity Assessment: Are We Already in the Future?

Post provided by Carola Gómez-Rodríguez & Alfried P. Vogler

Time flies… in the blink of an eye! And even more so in science. The molecular lab work we were used to two decades ago seems like ancient history to today’s PhD students. The speed of change in sequencing technology is so overwhelming that imagination usually fails to foresee how our daily work will be in 10 years’ time. But in the field of biodiversity assessment, we have very good clues. Next Generation Sequencing is quickly becoming our workhorse for ambitious projects of species and genetic inventories.

One by One Approach to Studying Biodiversity

For decades, most initiatives measured biodiversity in the same way: collect a sample of many individuals in the field, sort the specimens, identify them to a Linnaean species one at a time (if there was a good taxonomist in the group which, unfortunately, it is kind of lucky these days!), and count them. Or, if identification was based on molecular data, the specimen was subject to DNA extraction, to sequence one (or several) short DNA markers. This involved countless hours of work that could be saved if, instead of inventorying biodiversity specimen-by-specimen, we followed a sample-by-sample approach. To do this now, we just have to make a “biodiversity soup”.

Biodiversity assessment based on morphological identification and/or Sanger sequencing (“The one-by-one approach”)

Biodiversity assessment based on morphological identification and/or Sanger sequencing (“The one-by-one approach”)

Continue reading

Tiny Grains, Big Data: The Global Pollen Project

Post Provided by Andrew Martin

A drawer from the Oxford Long-Term Ecology Lab (OxLEL) pollen reference collections, which has been digitised into the Global Pollen Project reference set.

A drawer from the Oxford Long-Term Ecology Lab (OxLEL) pollen reference collections, which has been digitised into the Global Pollen Project reference set.

The Global Pollen Project is a new, online, freely available tool developed to help people identify and disseminate palynological resources. Palynology – the study of pollen grains and other spores – is used across many fields of study modern and fossil vegetation dynamics, forensic sciences, pollination, beekeeping, and much more. This platform helps to facilitate cross/multi-disciplinary integration and discussion, outsourcing identifications, expertise and the sharing of knowledge.

Pollen’s Role in Plant Conservation

Successful conservation of rare, threatened, and valuable plants is dependent on an understanding of the threats that they face. Also, conservationists must prioritise species and populations based on their value to humans, which may be cultural, economic, medicinal, etc. The study of fossil pollen (palaeoecology), deposited through time in sediments from lakes and bogs, can help inform the debate over which species to prioritise: which are native, and when did they arrive? How did humans impact species richness? By establishing such biodiversity baselines, policymakers can make more informed value judgements over which habitats and species to conserve, especially where conservation efforts are weighted in favour of native and/or endemic flora. Continue reading

Estimating the Size of Animal Populations from Camera Trap Surveys

Below is a press release about the Methods paper ‘Distance sampling with camera traps‘ taken from the Max Planck Society.

A Maxwell's duiker photographed using a camera trap. Marie-Lyne Després-Einspenner

A Maxwell’s duiker photographed using a camera trap. ©Marie-Lyne Després-Einspenner

Camera traps are a useful means for researchers to observe the behaviour of animal populations in the wild or to assess biodiversity levels of remote locations like the tropical rain forest. Researchers from the University of St Andrews, the Max Planck Institute for Evolutionary Anthropology (MPI-EVA) and the German Centre for Integrative Biodiversity Research (iDiv) recently extended distance sampling analytical methods to accommodate data from camera traps. This new development allows abundances of multiple species to be estimated from camera trapping data collected over relatively short time intervals – information critical to effective wildlife management and conservation.

Remote motion-sensitive photography, or camera trapping, is revolutionising surveys of wild animal populations. Camera traps are an efficient means of detecting rare species, conducting species inventories and biodiversity assessments, estimating site occupancy, and observing behaviour. If individual animals can be identified from the images obtained, camera trapping data can also be used to estimate animal density and population size – information critical to effective wildlife management and conservation. Continue reading

New Associate Editors

Today we are welcoming four new Associate Editors to Methods in Ecology and Evolution. Graziella Iossa (University of Lincoln) and Theoni Photopoulou (Nelson Mandela Metropolitan University) are joining as regular Associate Editors and Simon Jarman (Unversity of Porto) and Daniele Silvestro (University of Gothenburg) will be working on Applications articles. You can find out more about all of our new Associate Editors below.

Graziella Iossa

“I am an evolutionary ecologist with broad interests in behavioural and population ecology. My research has explored reproductive strategies and the evolution of male and female reproductive traits in mammals and insects and I have used a range of techniques to study the behaviour and welfare of wildlife. I have just started to explore interdisciplinary approaches with the aim to improve our understanding of the value and role of ecosystem services in human health, specifically for antimicrobial resistance.”

Graziella’s most recent paper – Micropyle number is associated with elevated female promiscuity in Lepidoptera – investigates the evolution of the micropyle, a tiny canal which sperm use to fertilise eggs in insects. This is the first study to show that micropylar variation is driven by female promiscuity – the more micropyles her eggs have, the more choice she is likely to have over which male fathers her offspring. Also, Graziella currently holds a NERC Valuing Nature placement which aims to combine perspectives from evolutionary ecology, microbial ecology, epidemiology, ecosystem science and public health to develop a new, holistic way of understanding antimicrobial resistance

Simon Jarman

“Methods employing epigenetics, environmental DNA analysis or bioinformatics for ecological research are improving rapidly and have clear potential for future development. My research focuses on creating new methods in these areas and using them to study population biology and biodiversity. Epigenetic markers for physiological features such as biological age can be used to determine key features of population biology such as age class distribution. Environmental DNA can be used to measure species distributions; biodiversity in environmental samples; and animal diet composition. I am interested in the molecular biology and computational approaches that are required to implement these methods; as well as how they can be used to study specific ecological questions.”

In November 2016, Simon published an Open Access article in Methods in Ecology and Evolution. ‘Optimised scat collection protocols for dietary DNA metabarcoding in vertebrates‘ explains how to collect scat samples to optimise the detection of food DNA in vertebrate scat samples. More recently, Simon was the last author of ‘KrillDB: A de novo transcriptome database for the Antarctic krill (Euphausia superba)‘ – which introduces the most advanced genetic database on Euphausia superba, KrillDB, and includes comprehensive data sets of former and present transcriptome projects.

Theoni Photopoulou

“I am interested in the way biological and ecological phenomena change in space and over time. My special interest is animal movement ecology and the mechanisms behind the patterns of movement we observe. Most of the time I work on ecological questions about how animals use their environment and the resources in it, using data collected remotely with animal-attached instruments. Marine biology was my first love so I will always have a soft spot for marine systems, especially movement of large marine vertebrates, but I work on all sorts of tracking data and also some non-tracking data.”

Theoni has also recently been published in Methods in Ecology and Evolution. Her article ‘Analysis of animal accelerometer data using hidden Markov model‘ appeared in the February issue of the journal (and provided the cover image). In the paper, the authors provide the details necessary to implement and assess a hidden Markov Model in both the supervised and unsupervised learning contexts and discuss the data requirements of each case. Another of Theoni’s articles has just been accepted for publication in Frontiers in Zoology. ‘Evidence for a postreproductive phase in female false killer whales (Pseudorca crassidens)‘ investigates the evidence for postreproductive lifespan (PRLS) in the false killer whale, using a quantitative measure of PRLS and morphological evidence from reproductive tissue.

Daniele Silvestro

“I am a computational biologist and my research focuses on (macro)evolution and the development of new probabilistic models to better understand it. I am interested in the implementation of Bayesian algorithms to model evolutionary processes such as phenotypic trait evolution and species diversification and extinction. I am also interested in historical biogeography and in particular in the estimation of dispersal rates and biotic connectivity between geographic areas. A lot of my work involves developing new models and algorithms and implementing them in computer programs. I have been using both phylogenetic data and fossil occurrences to infer deep time evolutionary dynamics and I am keen to see an improved integration between paleontological and neontological data in evolutionary research.”

In his most recent article – ‘Bayesian estimation of multiple clade competition from fossil data‘ – Daniele and his co-authors explore the properties of the existing Multiple Clade Diversity Dependence implementation, which is based on Bayesian variable selection, and introduce an alternative parameterisation based on the Horseshoe prior. He was also one of the authors of ‘Mammal body size evolution in North America and Europe over 20 Myr: similar trends generated by different processes‘, published in Proceedings of the Royal Society B earlier this year.

We are thrilled to welcome Simon, Graziella, Theoni and Daniele to the Associate Editor Board and we look forward to working with them over the coming years.

Digitizing Historical Land-use Maps with HistMapR

Habitat destruction and degradation represent serious threats to biodiversity, and quantification of land-use change over time is important for understanding the consequences of these changes to organisms and ecosystem service provision.

Historical land-use maps are important for documenting how habitat cover has changed over time, but digitizing these maps is a time consuming process. HistMapR is an R package designed to speed up the digitization process, and in this video we take an example map to show you how the method works.

Digitization is fast, and agreement with manually digitized maps of around 80–90% meets common targets for image classification. We hope that the ability to quickly classify large areas of historical land use will promote the inclusion of land-use change into analyses of biodiversity, species distributions and ecosystem services.

This video is based on the Applications article ‘HistMapR: Rapid digitization of historical land-use maps in R‘ by Auffret et al. This article is freely available to anyone (no subscription required).

The package is hosted on GitHub and example scripts can be downloaded from Figshare.

When Measuring Biodiversity, Do Individuals Matter?

Post provided by Samuel RP-J Ross

Close up of a black-capped babbler (Pellorneum capistratum), one of the species included in our study.

Close up of a black-capped babbler (Pellorneum capistratum), one of the species in our study.

Our newly-developed method simulates intraspecific trait variation when measuring biodiversity. This gives us an understanding of how individual variation affects ecosystem processes and functioning. We were able to show that accounting for within-species variation when measuring functional diversity can reveal details about ecological communities which would otherwise remain unseen. Namely, we found a negative impact of selective-logging on birds in Borneo when accounting for intraspecific variation which we could not detect when ignoring intraspecific variation.

Why Biodiversity Matters

Biodiversity is important for many reasons. One of the main reasons is its contribution to the range of goods and services provided by ecosystems (i.e. ecosystem services) that we can take advantage of, such as natural food resources or climatic regulation. It’s generally believed that biodiversity contributes to these services by increasing and maintaining ‘ecosystem functioning’ – often defined as the rate at which ecosystems are turning input energy (e.g. sunlight) into outputs (e.g. plant biomass). Continue reading

Capturing the Contribution of Rare and Common Species to Turnover: A Multi-Site Version of Generalised Dissimilarity Modelling

Post provided by Guillaume Latombe and Melodie A. McGeoch

Understanding how biodiversity is distributed and its relationship with the environment is crucial for conservation assessment. It also helps us to predict impacts of environmental changes and design appropriate management plans. Biodiversity across a network of local sites is typically described using three components:

  1. alpha (α) diversity, the average number of species in each specific site of the study area
  2. beta (β) diversity, the difference in species composition between sites
  3. gamma (γ) diversity, the total number of species in the study area.
Two tawny frogmouths, a species native to Australia. ©Marie Henriksen.

Two tawny frogmouths, a species native to Australia. ©Marie Henriksen.

Despite the many insights provided by the combination of alpha, beta and gamma diversity, the ability to describe species turnover has been limited by the fact that they do not consider more than two sites at a time. For more than two sites, the average beta diversity is typically used (multi-site measures have also been developed, but suffer shortcomings, including difficulties of interpretation). This makes it difficult for researchers to determine the likely environmental drivers of species turnover.

We have developed a new method that combines two pre-existing advances, zeta diversity and generalised dissimilarity modelling (both explained below). Our method allows the differences in the contributions of rare versus common species to be modelled to better understand what drives biodiversity responses to environmental gradients. Continue reading