Functional groups in changing ecological networks

Dr Anna Eklöf¹

¹Linköping University, Linköping, Sweden

When species shift distributions due to changed climatic conditions novel species interactions are formed. Several species may simultaneously enter new areas and there establish in a new ecological network consisting of  hundreds of new species. One key question when aiming to understand species range shifts are if and how ecological roles of species are changed – will a species belong to a similar functional group in the novel community? Community detection are often advocated as tools to help analyze and understand complex networks. More specific, one aims to identify important structural patterns within a network with possible implications for functionality. Here we have used the stochastic block models to explore a set of ecological networks, where the data consists of several subnetworks, either separated locally, regionally or by time. Our  aim is to identify similarities and differences between subnetworks.  We find that the group structure can vary widely between different sub networks. Group similarity is highly dependent on geographic position and species overlap. While large group structures are often fragmented or merged in sub networks comparisons species-wise group turnover is generally more limited. This means that smaller scaled group structures can move to or from larger group structures in different sites. However, species with fewer links are more susceptible to changes in group identity. These results highlight that there can be large structural effects even when species turnover is limited. This have implications for species range shifts indicating potential changes in species’ functional role when novel ecological communities are formed.

Biography:

My research interests are in analysis, modelling, and theory related to the structure, dynamics, and functioning of ecological networks. The goal with my research is to provide detailed understanding of the factors driving species interactions, and thereby increase our knowledge about ecosystem functioning and how they respond to different kinds of disturbances, such as loss of biodiversity, habitat fragmentation and global warming.