To understand ecological change also from an ecosystem functioning perspective, it is
important to consider the associated functional characteristics of species and not only focus on the names of species per se, writes Benjamin Weigel, BlueAdapt postdoctoral researcher at the Research Centre for Ecological Change, University of Helsinki.
Traits – important, but often not considered
When investigating how species communities change as a response to a changing environment and human induced pressures, we, as ecologists, often only focus on the changes in abundance and biomass, or the total number of different species we find (biodiversity).
However, many species “do” similar things or react in similar ways to environmental change. While the traditional taxonomic way of investigating community changes is of course valid, it omits the underlying functional aspects of altered communities. One way of overcoming this challenge is to include species’ traits into analyzing ecological change.
Traits are characteristics of species that can describe what the species is doing in a more
ecological meaningful way than its name. So, instead of only looking at the scientific name of a species, a trait-based approach considers multiple aspects of the species and “translates” the species name into a suite of associated characteristics, such as its size, the feeding mode, a preferred habitat type, a particular behavior, or if it is toxic or not.
This is, depending of the research question, often more informative and relevant than knowing the presence of a particular species, especially when focusing on ecosystem functioning, which is defined as joint effect of all processes that sustain an ecosystem. If we link how species traits contribute to such processes, we can improve models that can explain the threats to particular ecosystem functions.
BlueAdapt uses a novel framework to model community responses to environmental change
When modeling species communities under different e.g. blue growth scenarios, the geographic distribution, the habitat preference, as well as species interactions within a community, ultimately depend on the individual traits of a species. In BlueAdapt, we are using a novel framework that incorporates such information into in a species distribution model.
The Hierarchical Modelling of Species Communities (HMSC), a statistical framework developed at the University of Helsinki, is a joint species distribution model that simultaneously also combines information on species traits in addition to the environmental measures. Using those results, we can now also model the community responses to environmental change from a more functional perspective in one joint distribution model.
In my current work I am investigating changes in phytoplankton communities across Finnish lakes in response to environmental changes such as nutrient loads and altered temperature over the past 40 years. I use HMSC to predict species compositions under certain conditions and focus on the underlying functional changes including relevant phytoplankton traits such as toxicity, nutrient preferences, size and other morphological characteristics. I am particularly interested in the development of toxic species and how we can better predict the formation and strength of harmful algae blooms to ultimately recommend better management targets.
Considering species traits in distribution modeling is a promising tool to better understand and predict community developments under environmental changes. It also includes the functional implications of community changes, and therefore provides a useful framework for management when aiming to conserve and maintain ecosystem functioning.
The writer Benjamin Weigel is a postdoctoral researcher at the Research Centre for Ecological Change, University of Helsinki.