Large-scale emergent patterns in semi-arid ecosystems
One of the most fascinating aspects of complex biological systems is the emergence of patterns. Interactions between biotic and abiotic components of an ecosystem can generate non-trivial spatial organization at any observational scale. In this talk, we will discuss about the large-scale vegetation patterns that emerge in semi-arid ecosystems such as the mysterious Fairy Circles in Namibia. Traditionally, vegetation-water reaction-diffusion models have been used to replicate the vegetation snapshots obtained in these ecosystems using remote sensing. However, in areas where social insects are present, there is more than meets the eye. We will use tools and concepts from statistical physics to characterize the role of social insects and determine their effect not only on the emergent patterns, but on the whole ecosystem. By using a combination of mathematical models, we will understand the interplay between insects, vegetation, and the rest of the environment, thus identifying the mechanisms giving rise to these patterns and how they change with time. As we will see, the non-trivial feedbacks triggered by social insects help the ecosystem resist desertification and contribute to its faster regeneration.