Whole Azorean Arthropod diversity: understanding the trophic relations

Objectivo

This PhD Project aims to understand the role of functional diversity, ecosystem services and trophic chains in the native Azorean forests, and how these are affected by the disturbance that many of such forests are undergoing. 

The two main aims are thus: 

1. It is essential to know not only the species composition and the structure of the communities in a certain habitat but also to understand i) the role of biotic interactions and ii) the ecological functions exerted by their populations. There are still many voids in the complete understanding of the ecological services provided by arthropods and their role in the transformation and flow of energy and mater in the ecosystems. Therefore, an exhaustive study of the arthropod functional diversity in Azorean native forests and the structure and composition of trophic chains encompassing insufficiently studied groups is highly necessary. 

1.  The disturbance in the forests may lead not only to a change in the existing ecosystem services and functions but also to a change on the role of each single population inside of biotic communities. As such, we propose to study how extended are the changes in populations and their functions across an anthropogenic disturbance gradient in the native Azorean forests. For this reason comparison between native forests with different levels of disturbance will be performed.
   In particular, we aim to examine the complete functional hyperspace in each of a number of forests along a disturbance gradient, in order to answer to the following questions: i) are components of the functional hyperspace especially vulnerable to exotic species?; ii) are there empty functional spaces still not occupied by exotic species?; iii) is the number of species randomly established across the whole functional hyperspace? 

One of the major challenges of the 21st century is to carry out a full inventory of the biodiversity existing on the planet, challenging the Linnean shortfall. In addition, the distribution of described species is mostly unknown as is the abundance of species and their changes in space and time (the Wallacean and Prestonian shortfalls, respectively) (Cardoso et al. 2011). To help ameliorate these shortfalls for the Azores and to simultaneously achieve the main goals of this project it is necessary to sequentially, undertake 9 additional aims: 

1. To review the existing literature, providing a solid base of knowledge necessary to optimize the remaining tasks of this project, enabling by this way the compatibility between the collected and the preexisting data; 

1. To select the study areas along a comprehensive disturbance gradient and to set an optimal sampling strategy to be applied to each area, with the objective of sampling the entire population of the communities (All Taxa Biodiversity Inventory – ATBI). A complete assessment of the arthropod alpha diversity present will be performed through the quantification of the species composition and richness of epigean, tree bark, soil and canopy arthropods, including groups insufficiently studied in previous works such as the Collembola, Hymenoptera and Diptera (vide Borges et al. 2005a), while guaranteeing direct comparability with previously collected data by using standardized and optimized sampling protocols; 

1. Fieldwork, to be performed with the same ATBI strategy at each site ; 

1. To sort and to identify all the collected specimens, assigning distinct morphospecies and, whenever possible, identifying to species level; 

1. To perform a quantitative assessment of the total biomass present in each plot, estimating the total biomass for the forest patches and estimating the biomass per trophic level; 

1. To codify all morphospecies collected into guilds, according to a set of functional characteristics, and to estimate the functional diversity at the local level; 

1. To determine the composition of the trophic chains, assessing the importance of arthropods in the transformation and flow of energy and mater; 

1. To study the impact of the anthropogenic disturbance gradient in the arthropod functional diversity and trophic chains, while trying to find patterns along that gradient in the Azorean native forests. 

1. To identify “paths to co-extinction”, i.e., relate the abundance of some species along the anthropogenic disturbance gradient and find if the changes in the abundance of some species may cause changes in other, trophically related, species. 

Invertebrates and their ecological services are mostly unknown to the general public (the public dilemma) (Cardoso et al., 2011). To help overcome this dilemma, the completion of one additional aim is also desirable, namely: 

• Communication to the general public through the creation of informative and didactic material and by putting available to all public the images of all the species occurring in Plots of Native forest in Azores, using the facilities of Azorean Biodiversity Portal (http://www.azoresbioportal.angra.uac.pt/).