Restoring ecological communities
The aim of the MODELECORESTORATION (Ecological restoration in model communities) project was to develop a theoretical framework to support ecological restoration. The team compared model predictions to real restored and degraded communities in terms of structure (community composition) and form (stability). Three main questions were addressed, the first of which was to investigate whether certain ecological properties can be restored in degraded communities. The second question was how much habitat needs to be restored to regain a minimum level of stability. Finally, predictions were made regarding what kinds of communities are easiest to restore. Project partners created models of communities of interacting species to define different restoration scenarios. A wide variety of variables were used that described the communities' biodiversity, food web structure and stability. The general patterns of these communities were similar to those found in nature and their statistical properties aligned with reported values for real food web communities. Algorithms defining habitat loss and restoration were also applied to the simulation models and the model habitat destroyed in 10 % increments, after which the habitat was left to stabilise. Once stabilised, the amount of habitat destroyed was restored and communities left to evolve until a stable state was achieved. Researchers then measured diversity, food web properties and stability for communities under destruction and restoration. Results showed that it was possible to restore ecological properties to degraded communities, but recovery rates depend upon the original level of destruction. Recovery rates of communities living in the habitats subject to the greatest levels of destruction take longer to stabilise and are therefore less resilient. Losing species was found to be the last consequence of habitat loss, but total abundance takes longer to recover. The proportion of seed dispersal and plant pollinator interactions versus predator-prey and host-parasitoid interactions was shown to play an important part in restoration of the simulated communities. Models also revealed that many communities showed opposite patterns (e.g. increase and decrease) in the initial recovery stages, indicating the importance of long-term monitoring. MODELECORESTORATION also conducted field experiments, sampling biological communities in salt marsh islands in the Bristol Channel, in the United Kingdom. Results supported findings from the simulation models showing that those communities from islands experiencing total habitat destruction take longer to restore. This supports the theory that recovery rates strongly depend upon the magnitude of destruction.
