Periodic Reporting for period 1 - SOILBIODIV (Beyond the limits of scale: a novel pipeline for the measurement of soil arthropod biodiversity)
Berichtszeitraum: 2016-07-01 bis 2018-06-30
Logistical difficulties for the identification and quantification of soil arthropods from a single standard soil sample arise from the very high numbers of individuals (up to 100,000 per m2 of soil), and the typically cryptic nature of species boundaries. However, recent technical advances provide a tool to bridge this knowledge gap. In recent years high throughput DNA sequencing (HTS) has been harnessed to quantify the microbial diversity of ecosystems and is now revolutionizing the study of complex and hyperdiverse macroscopic communities. Now, for the first time, we can obtain quantitative measures of the mesofaunal biodiversity of soil, and its spatial structure and functional dimension, through the application of tailored 'metabarcoding' and 'mitochondrial metagenomics' protocols. SOILBIODIV applied these novel HTS techniques to develop new molecular protocols within a multidisciplinary project for the characterization of soil arthropod communities (beetles, springtails and mites) in an insular setting of the Canary Islands.
The main objectives of SOILBIODIV were (1) Develop and validate an interdisciplinary metabarcoding and mitochondrial metagenomics pipeline for robust measures of invertebrate soil biodiversity, applicable across all spatial scales; and (2) characterize soil arthropod mesofauna richness, community structure and turnover within and among ecosystems and islands, identify introduced species and associated biodiversity risks.
Data generated within SOILBIODIV allows for the estimation of community responses and vulnerability of soil invertebrate biodiversity to (i) climate change and (ii) invasive species, two important drivers of global change. Resources and results generated in SOILBIODIV will be very relevant for (i) the European Initiative BEST (Biodiversity and Ecosystem Services in Territories), (ii) the new International Platform IPBE (Intergovernmental Platform on Biodiversity & Ecosystem Services), (iii) the Strategic Objective C of the Strategic Plan for the Biological Diversity 2011-2020 (Aichi Targets www.cbd.int) and for (iv) the quantification and control of biodiversity loss under climate change on Special Territories of the European Union (ORs and OCTs) as highlighted by the recent International Conference on Biodiversity and Climate Change (October 2014, see www.cbd.int).
WP1.1. Sampling: Preparation of Berlesse Lab (equipped with a battery of Berlesse apparatus), collecting soil samples in Tenerife, and soil fauna extraction and preservation. Months 1-3. Sampling in La Palma in month 6. Specimen sorting: Sample processing and fauna classification. Months-2-4 and 6. (Milestones WP1.1 " Finishing sampling and specimen sorting" achieved)
WP1.2. Generation of reference mitogenomes: Assemble and annotation of complete mitochondrial genomes for Coleoptera, Acari and Collembola (300 mitogenomes) and generation of reference phylogenetic tree. Months 4-7. (Milestones WP1.1 "Mitochondrial genomes and trees generated" achieved)
WP1.3. Metabarcode sequencing: Molecular lab work for the metabarcode sequencing of 96 samples in the IlluminaMiSeqplatform. Month 7. (Milestones WP1.3. "Metabarcode sequences generated" Achieved after the early grant termination (month 7.5) as planned to be finished in month 9).
Together these results will be part of a minimum of two publications in top scientific journals. The first paper is in an advanced phase of writing, and deals with the phylogenetic tree of soil mites based on the more than 100 mitogenomes generated (where a single one was previously available for the main group of soil mites, Oribatida). The second paper will be based on the generated metabarcodes, where we are currently in the analytical phase. Note that the early termination was due to the 3-year research position gained by CA that is associated with a new project to study soil biodiversity that will build up on the SOILBIODIV project.