rmangal: making ecological networks easily accessible

[This article was first published on rOpenSci - open tools for open science, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here)
Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.

In early September, the version 2.0.0 of rmangal was approved by
rOpenSci, four weeks later it made it to CRAN. Following-up on our experience we
detail below the reasons why we wrote rmangal, why we submitted our package to
rOpenSci and how the peer review improved our package.

Mangal, a database for ecological networks

Ecological networks are defined as a set of species populations (the nodes of
the network) connected through ecological interactions (the edges). Interactions
are ecological processes in which one species affects another. Although
predation is probably the most known and documented interaction, other less
noticeable associations are just as essential to ecosystem functioning. For
instance, a mammal that unintentionally disperses viable seeds attached to its
fur might help plants to thrive. All of these interactions occur simultaneously,
shaping ecosystem functioning and making them as complex as they are

Recording and properly storing these interactions help ecologists to better
understand ecosystems. That is why they are currently compiling datasets to
explore how species associations vary over environmental gradients and how
species lost might affect ecosystem functioning. This fundamental research
question should help us understanding how ecological networks will respond to
global change. To this end, the Mangal project https://mangal.io/#/
standardizes ecological networks and eases their access. Every dataset contains
a collection of networks described in a specific reference (a scientific
publication, a book, etc.). For every network included in the database, Mangal
includes all the species names and several taxonomic identifiers
(gbif, eol,
tsn etc.) as well as all interactions and their types.
Currently, Mangal includes 172 datasets, which represents over 1300 ecological
networks distributed worldwide.

An R client to make ecological networks easily accessible

In 2016, the first paper describing the project was published1. In
2018, a substantial effort was made in order to improve the data structure and
gather new networks from existing publications. In 2019, the web API was
rewritten, a new website launched and hundreds of new interactions were added.

Because of all these modifications, the first version of rmangal was obsolete
and a new version needed. It is worth explaining here why the R client is an
important component of the Mangal project. Even though Mangal has a documented
RESTful API, this web technology is not commonly
used by ecologists. On the contrary, providing a R client ensures that the
scientific community that documents these interactions in the field can access
them, as easily as possible. The same argument holds true for the Julia
that Timothée Poisot
wrote because Julia is increasingly popular among
theoreticians, that can test ecological theory with such datasets.

We had two main objectives for rmangal 2.0.0. First, the rmangal
package had to allow users to search for all entries in the database in a very
flexible way. From a technical point this means that we had to write functions
to query all the endpoints of the new web API. The second goal was to
make the package as user friendly as possible. To do so, we used explicit and
consistent names for functions and arguments. We then designed a simple workflow, and
documented how to use other field related packages (such as igraph) to
visualize and analyze networks (see below). You can find further details in the vignette “get
started with rmangal”

# Loading dependancies

# Retrieving all ecological networks documented in Haven, 1992
havens_1992 <- search_references(doi="10.1126/science.257.5073.1107") 
                  %>% get_collection()

# Coerce and visualize the first network object return by mangal with ggraph 
ggraph(as_tbl_graph(havens_1992[[1]])) +
     geom_edge_link(aes(colour = factor(type))) +
     geom_node_point() +
     theme_graph(background = "white")

A successful peer review process

After some hard work behind the screen and once we deemed our two objectives
achieved, we decided to submit the rmangal package to rOpenSci for peer review. We
did so because we needed feedback, we needed qualified people to critically
assess whether our two main objectives were achieved. Given the strong expertise
of rOpenSci in software review, and given that our package was in-scope,
submitting rmangal to rOpenSci was an obvious choice.

We had very valuable
from Anna
and Thomas Lin Pedersen. They carefully assessed
our work and pointed out areas where improvement was required. One good example
of how their review made our package better concerns the dependencies. We
originally listed sf in Imports as we used it to filter networks based
on geographic coordinates. But the reviewers pointed out that this was not an
essential part of the package and that sf has several dependencies. This made us realize that for one extra feature, we were substantially
increasing the number of indirect dependencies. Following the reviewers’
suggestions, we moved sf to Suggests and added a message to warn users
that to use the spatial filtering

requires sf to be installed. Similarly, based on another good comment, we
added a function to convert Mangal networks into tidygraph objects
and we documented how to plot Mangal networks with ggraph (and so we
added those packages in Suggests). Such improvements were very helpful to
properly connect rmangal to the existing R packages. The plethora of R packages
is one of its major strengths, and connecting a package properly to others makes
the entire ecosystem even stronger.

We are now looking for user experience feedback, not only for rmangal
(vignette) but also
for the web API (documentation) and the mangal.io
. We welcome suggestions and contributions,
especially for the documentation by opening new issues on GitHub
rmangal). In the future, we
envision that rmangal will integrate functions to format ecological networks for
ecologists willing to add their datasets to Mangal. This will likely be the next
major release of rmangal.


We are thankful to all contributors to
and to all ecologists
that have spent countless hours in collecting data. We would like to thank Anna
and Thomas Lin Pedersen for thorough reviews as
well as Noam Ross for handling the review

  1. Poisot, T. et al. mangal – making ecological network analysis simple. Ecography 39, 384–390 (2016). https://doi.org/10.1111/ecog.00976

To leave a comment for the author, please follow the link and comment on their blog: rOpenSci - open tools for open science.

R-bloggers.com offers daily e-mail updates about R news and tutorials about learning R and many other topics. Click here if you're looking to post or find an R/data-science job.
Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.

Never miss an update!
Subscribe to R-bloggers to receive
e-mails with the latest R posts.
(You will not see this message again.)

Click here to close (This popup will not appear again)