Name: Tarroso P

Biodeserts supervisor: Brito JC

Co-supervisors: Alves PC, Rachid Cheddadi, University of Montpellier, France

Title: Environment and biodiversity: A multidisciplinary approach to dynamic patterns in the Iberian Peninsula

Institution: University of Porto

Status: Completed



The multidisciplinary approach to the study of biodiversity patterns offers detailed analyses that are often impossible to achieve under single-discipline studies. This is demonstrated here with an integrative approach merging data from different research fields, including landscape ecology, molecular evolution, paleoecology and climate modelling. The Iberian Peninsula offers exceptional conditions for the development of these studies: there are high levels of endemism, climate variability and abundance of data available stemming from different fields. The integrative approach presented here is extended to a different time and spatial scales, covering a wide period from the late-Quaternary (15,000 to 3,000 years before present) to the current century, with different questions addressed at macro- and micro-scales.

In this scope, two new software applications were developed (chapter 3): 1) E-Clic (section 3.1) is a converter of future climate prediction data to commonly used formats in landscape ecology; and 2) Simapse (section 3.2) is an ecological niche modelling tool that implements artificial neural networks to model species’ distribution data. Moreover, thirteen spatial layers for three variables representing the late-Quaternary climate were built. This was achieved with an improved method for the reconstruction of past climate using fossil pollen data as a proxy(chapter 4, section 4.1).

Integration of all data and methods was done at two different scales (chapter 5). In a macro-scale context, it was achieved by the analysis of the dynamics of Iberian herpetofauna species composition in the past and predicted for the current century under the current trend of climate warming (section 5.1). A micro-scale analysis was performed for the study of ecological divergence in a contact zone between three viper species (Vipera latastei, V. aspis and V. seoanei) using ecological niche modelling and multi-trait analysis (nuclear, mitochondrial and morphological; section 5.2).

The Iberian climate in the late-Quaternary was characterized by a general warming trend with abrupt transitions that had wide impacts in the spatial organization of each climate variable. The area of the Iberian Peninsula was clustered into four distinct groups exhibiting similar patterns of climate evolution. The results of the macro-scale analysis revealed that biodiversity patterns were largely affected by these processes, with areas of high velocities of species composition change, but also areas with low velocities related to long species persistence. By the end of the current century, major changes on species richness patterns are predicted that will pose many conservation challenges.

The application of Simapse to the study of the hybrid zone at micro-scale resulted in an innovative approach to the study of ecological divergence in the range limits of the three vipers. The results allowed a full description of the contact zone, both at genetic and environmental levels, with a characterization of the population structure. Different ecological requirements from each species were found and a transitional ecotone was suggested where the hybrids were identified.

The integrative approach followed here provided exhaustive examples describing macro- and micro-scale processes occurring in Iberian Peninsula, confirming the potential of merging results from different research fields. The results presented here are expected to support the conservation effort on Iberian herpetofauna and to have impact on future studies of hybrid zones within an ecological context. However, the potential of the developed tools is not limited to the analyses carried here, and it is also expected the expansion of the applicability to other domains related to biodiversity.