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

Issue 8.4: Technological Advances at the Interface of Ecology and Statistics

Issue 8.4 is now online!

The April issue of Methods, which includes our latest Special Feature – “Technological Advances at the Interface of Ecology and Statistics” – is now online!

This new Special Feature is a collection of five articles (plus an Editorial from Guest Editor David Warton) inspired by the December 2015 Eco-Stats conference at the University of New South Wales in Australia. It shows how interdisciplinary collaboration help to solve problems around estimating biodiversity and how it changes over space and time.

The five articles are based on joint talks given at the conference. They focus on:

As David Warton states in his Editorial, “interdisciplinary collaboration and the opportunities offered by recent technological advances have potential to lead to interesting and sometimes surprising findings, and will continue to be fertile ground for scientists in the foreseeable future”. Meetings like Eco-Stats 15 and Special Features like this one will, hopefully, help to encourage these sorts of collaborative research projects.

All of the articles in the ‘Technological Advances at the Interface of Ecology and Statistics‘ Special Feature will be freely available for a limited time.
Continue reading