Ecological Niche Models Reveal Climate Change Effect on Biogeographical Regions: The Iberian Peninsula as a Case Study

Diana Sousa-Guedes,Salvador Arenas-Castro,Neftalí Sillero

doi:10.3390/cli8030042

Abstract

How species are distributed on Earth depends largely on climate factors. Whenever these environmental conditions change, species tend to shift their distributions to reach more favourable conditions. Distinct sets of species similarly distributed (i.e., chorotypes) occur in biogeographical regions with homogeneous environmental conditions. Here, we analysed whether biogeographical regions are unstable over time (from the past to the future). We modelled the realised niche of amphibians and reptiles in the Iberian Peninsula in the present, and several past and future climate scenarios. Then, we used Jaccard’s index and the unweighted pair group method (UPGMA) to define the biogeographical regions. Our results suggest that the biogeographical regions of Iberian amphibians and reptiles changed greatly over time, due to the climatic changes between periods. Biogeographical regions composed of species with Atlantic affinities changed particularly, overall gaining suitable areas in past colder periods and losing suitable areas in warmer periods. The areas of refugia for amphibians over time corresponded to the most humid regions (north-west of the peninsula), while the most important areas for reptiles occur in the south and on the Atlantic coast. The identification of biogeographical patterns considering past climate changes is essential to better apply conservation measures.

Highlights

The current biodiversity crisis has led to an increasing interest in biogeographical studies attempting to understand the spatial patterns of species distributions, boosted by technological advances such as geographical information systems and remote sensing [1,2,3,4,5]
We selected the Iberian Peninsula (Figure 1) as a case study because (1) it is a hotspot of biodiversity [49]; (2) it is an area where amphibians and reptiles are strongly impacted by climate change [53]; and (3) it works as a close system thanks to its peninsular condition, separated from the rest of Europe by the Pyrenees
Our results suggest that the biogeographical patterns of Iberian amphibians and reptiles changed greatly over time

Summary

Introduction

The current biodiversity crisis has led to an increasing interest in biogeographical studies attempting to understand the spatial patterns of species distributions, boosted by technological advances such as geographical information systems and remote sensing [1,2,3,4,5]. Much effort has been dedicated to analyse how species are distributed across space, and how they are organised in regions of similar characteristics (e.g., [6,7]). These so-called biogeographical regions are ecologically and geographically defined areas of the Earth, generally with homogeneous geologic and environmental conditions [5,8,9]. Biogeographical regions are composed of distinct assemblages of species and communities, known as chorotypes, with statistically similar distributions [8,9,10]. More than a century after, the biogeographical units proposed by Wallace (1876) are still valid; they have nowadays improved substantially with

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