Project PTDC/BIA-BIC/0054/2014

Our specific goals are:

1) Characterize variations between TD, FD and PD scales from the plot scale to the archipelago scale;

2) Identify the relative importance of spatial, historical and environmental factors that affect TD, FD and PD variations between scales;

3) Determine the food specialization of the various spider species in order to quantify the importance of ecological interactions within communities in generating patterns of co-occurrence and speciation.

To achieve this objective we will: 1) develop an intensive and standardized fieldwork [8] in different locations and habitats of different islands in different archipelagos, 2) collect functional genetic characteristics and trophic preferences using new DNA sequencing technologies, and 3) implement statistical methodologies largely recently developed by our team [9] to reveal the mechanisms responsible for diversity patterns.

This project follows on from four successful FCT projects led by the PI and several complementary efforts that were initiated in our laboratory. In addition, team members have published extensively on island biogeography, evolution, and conservation using Macaronesia as a model [1012].

These studies have contributed to Macaronesia becoming one of the most studied island systems in the world and the team members being internationally recognized for their competence.

One ​​of the most important challenges in ecology has been to understand the processes that originate and maintain the spatial heterogeneity of biological diversity on a global scale [1]. As a result, several hypotheses have been discussed: some emphasize ecological niche-related processes, others emphasize historical contingencies, and many support the role of neutral processes [2]. Reconciling these points of view is one of the greatest challenges of contemporary ecology.

Although most studies focus on species identification (e.g. Taxonomic Diversity TD), there has been an effort to include information about their abundance, evolutionary history (e.g. Phylogenetic Diversity PD) ) and its role and functions in the ecosystem (e.g., Functional Diversity FD) to explain patterns of diversity [3]. Three problems seem to underlie the difficulty in studying all different aspects of diversity simultaneously: 1) the need for standardized data from many sites that allow the integrated study of all aspects, including data on species abundance, phylogeny and functional roles; 2) the difficulty of obtaining relevant species characteristics that can respond to biotic and abiotic factors (particularly for arthropods) 3) the inherent complexity of relating the various mechanisms at multiple scales for various measures of diversity and uncovering the processes, exclusive or shared, which explain the spatial variation of diversity [e.g. 4]. So far, no study has managed to solve these problems for any taxonomic group.

Using the Macaronesia Islands as a geographic model and spiders as model organisms, the MACDIV project has as its main objective to advance the fundamental knowledge of the factors responsible for the patterns of diversity. The islands for their unique geographic features and simplified communities are recognized as generating models of fundamental ecological theory [5], in contrast to the more complex continental regions. Macaronesia encompasses four major oceanic archipelagos spread along a latitudinal gradient across the Atlantic Ocean. Spiders present a set of unique characteristics for large-scale studies, as they add to their high taxonomic diversity, a more or less well-resolved phylogeny at higher taxonomic levels [6] and their lifestyles and functional roles in the ecosystem are known. [7]. Focusing on local scales, this project aims to dissect the taxonomic, evolutionary and functional bases of the spatial heterogeneity of biological diversity, offering a unique opportunity to understand the processes that led to the great diversification of life on these islands. Bearing in mind that the “biodiversity crisis” is particularly incisive in the islands [5], we hope that the MACDIV can be the basis for the development of conservation strategies for these island ecosystems.

The results of this project are relevant as they contribute to the EU's BEST indicators on essential biodiversity variables for the islands and for the new IPBE platform. In addition, it will contribute to the Strategic goals of the Convention on Biodiversity for 2020 (see www.cbd.int). Finally, we hope that this project will provide extremely valuable background information on the structuring processes of the diversity of these outermost regions of Europe