For several years, conservation efforts around the world have been focused on single species (keystone, flagship and umbrella species). This approach has been criticized mainly for not considering ecological processes, and therefore being ineffective for preserving ecosystems (Simberloff, 1998). Nowadays, conservation programs are being planned based on a holistic approach, taking into consideration the functioning ecosystems and their associated ecosystem processes (Wilson et al., 2009). It is broadly known that the structure of a community and its capacity to remain functional are connected in a complex manner. Nevertheless, the degree of influence of a species’ identity on the persistence of the community it belongs to, as well as the variation degree of a species’ role as function of its community, is still uncertain. In order to fill that gap in our knowledge, this week’s discussion paper proposes a mathematical model based on “network motifs” that aims to determine the role played by a species and its importance in dynamics of a community. This model was tested using data from 32 empirical food webs from different environments, concluding that the species´ roles and their dynamic importance are inherent and intrinsic features developed as part of the evolution of taxa. Thus, some taxonomic groups tend to play the same role in different communities.
During our discussion, the group concluded that although the approach seemed very useful, the conclusions from the modelling were not new and that the authors could have done more to show how the model could be applied to the conservation of species and communities. Furthermore, some concepts like “benefits of the species” and community persistence were not properly explained in the main paper, leading to some confusion.
Question:
Besides identifying species’ roles in communities, how could this model be applicable and helpful in establishing conservation priorities?
References cited:
Simberlof, D. (1998). Flagships, umbrellas, and keystones: is single-species management passé in the landscape era?. Biological Conservation 83(3) 247-257.
Wilson, K. A., Carwardine, J. and Possingham, H. P. (2009), Setting Conservation Priorities. Annals of the New York Academy of Sciences, 1162: 237–264
I think that this modelling approach gives us a uniquely useful metric that we can use to measure community structure with. However, I think that we need to use it to do more comparative work on a wide range of communities to build up an idea of how it behaves. I would also like to see how it relates to functional trait profiles of communities because I think that these two approaches could be very complementary in food web research. Once we do these things, we might have a better idea of what it can really add as an approach for addressing conservation issues.
ReplyDeleteTo answer the question posted "how can the model be applicable and helpful in establishing conservation priorities?" I feel also that the model needs to be applied to more diverse and complex communities. The writers acknowledge that the similarities across the 10 food webs they compared may be sufficient to account for the observed results.
ReplyDeleteA large part of conservation in New Zealand is controlling introduced pest species and species reintroductions. Understanding a species role in complex community is an important part of that control. The use of a model such as the network motif model may give insights into how community dynamics may change when a species is removed or introduced. We will follow developments of this model with interest.
I like the idea of conservation programs being planned based on a holistic approach and taking into consideration the functioning ecosystems and their associated ecosystem processes. I believe it is important to look at the community level rather than only at species level since it all effect eachother. For prioritizing conservation the whole perspective must be considered thus the role of each species AND the interactions between species.
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