Topological properties and robustness of polar food webs: assessing the vulnerability of polar ecosystems to global changes using a complex network approach

Arctic ice loss and warming and the instability of West Antarctic Ice Sheet are considered to be Tipping Elements in the Earth climate system and polar biota is particularly vulnerable to climate change. Whereas the assessment of the impacts of climate change on ecosystems is often addressed through the evaluation of effects on individual species, their responses are not isolated but dependent on the interactions with species at the same or adjacent trophic levels. Here we use complex network analysis to characterize the topological properties of the largest Arctic and Antarctic marine food webs in literature, and revealed structural differences that can determine distinct responses of these ecosystems to environmental forcing. Moreover, we study the propagation of impacts derived from species loss on these polar food webs by comparing the responses of the food webs when subjected to various extinction sequences, analyzing the effect of the different order of removal of each species in each food web. The examination conducted here reveals that zooplankton species, Antarctic krill and Calanus copepods in the Arctic, play a crucial role as keystones species affecting the stability and coherence of the food web.


In collaboration with Rozenfeld AF; Marquet PA; Duarte CM - LINCGlobal (IMEDEA - PUC - UFRJ)