PS 28-87
Influences of species body mass over the assembly mechanisms of the Intraguild-predation module

Tuesday, August 11, 2015
Exhibit Hall, Baltimore Convention Center
Carlos A. Marcelo-Serván, Ciencias Matemáticas, Universidad Nacional Mayor de San Marcos, Lima, Peru
Walter Cabrera-Febola, Ciencias Biológicas, Universidad Nacional Mayor de San Marcos, Lima, Peru

Over the years, the body mass of a species has proven to be an important trait which influences how a species within a community interacts with the other members of it. In particular, previous work have described how the distribution of body masses in a food web influence its dynamic stability; but there had not been a work relating it to the assembly mechanisms of food webs. In this work we start to fill this gap by studying how the expression of the assembly paths of the Intraguild-predation module is affected by the body masses of the interacting species,to do so we use a lotka-volterra model parameterized using the framework proposed by Pawar, and derive invasibility criterions for each possible scenario explicitly in terms of the body mass of the species.To make the analysis simpler we express the body mass of the basal resource and the IG prey in terms of the mass of the IG predator and the respective prey-predator size ratio, the framework used also allow us to test the differences between 2D and 3D habitats and different foraging strategies. 


In the parameter space defined in terms of the IG predator mass and the prey-predator ratios, it is observed that each point in which a given invasibility criterion (e.g IG predator can invade the IG prey-Resource subsystem) is satisfied is related to a particular subset of it, this set differs between 2D and 3D habitats, and among foraging strategies. In particular the set in which both assembly paths that lead to the full module, which is an intersection of two of the above sets, could be expressed is relatively small.

The results show that a particular body mass combination in the module could favor or restrict the expression of an assembly path toward the full module and that it could have different effects in habitats of different dimension or if the predators differ in foraging strategies. We believe that this is a good starting point in the development of a theory that relates metabolic ecology to food web assembly.