Objective & Methodology

The long-term objectives of the work are the implementation of standardised procedures for science-led biodiversity evaluation, and the establishment of sampling plots for long-term monitoring and/or complementary biological analyses.

The short-term objective is to develop the necessary methodology and undertake a series of intra-regional biodiversity assessments, the exact locations of which will be formulated by discussion with regional biodiversity managers and stakeholders.

The strategy we will employ for characterising community level biodiversity in flowering plants will be to further populate the DNA bank of the Canarian Flora at the JBCVCSIC (Partner 6) and to develop a new DNA bank for Réunion Island. The DNA banks will provide the resource for sequencing a standardised set of genes to derive quantitative estimators of phylogenetic relatedness among species present in sample plots while taking into account cryptic evolutionary divergence that might have arisen within particular lineages across habitats or localities. This work has recently been completed, and a DNA bank established within the Azores by a collaborative project involving Partner 5.

Macro-invertebrate and soil micro-invertebrate sampling will be focussed within sampling plots, with standardised sampling protocols adopted across plots. To provide added value to our project, we take advantage of the global initiative to associate a reference mtDNA barcode sequence to all animal species.  All sampled invertebrate taxa will be sequenced for the 658bp barcode amplicon, enabling us to simultaneously assess genetic divergence within focal taxa across sampling plots, and identify species introductions.

Methods

  • Plant sampling for DNA banking will be coordinated with a focus on obtaining samples of all flowering plants, based on the manual developed by the DNA bank facility at the JBCVCSIC. This will be achieved by a combination of (1) direct field sampling, (2) use of already available archived material where available (e.g. dried silica gel collections already in possession of the project partners), (3) available herbarium material (including the ongoing DNA banking initiatives of Partners 3 & 4 on native plants of Réunion Island and Partner 6 on the native plants of the Canary Islands).
  • Macro-invertebrate sampling will be undertaken within plots by soil sampling, leaf litter sampling, pitfall trapping, malaise and canopy (SLAM) trapping, and manual extraction. Samples will be sorted into morphospecies and then identified to species level. Specimens of each morphospecies from each plot will be DNA extracted and sequenced for the mtDNA COI barcode region.
  • For soil micro and meso-invertebrate component of sampling we will focus on the Collembola to capitalise on recent molecular advances by the project leader BCE for their analysis utilising next generation sequencing technology (8). Sampling of Collembola within each location will be standardised, following a protocol used successfully by project leader BCE in a recent Leverhulme Trust funded project to develop the protocols presented here.

We will use the phylogenetic endemism (PE) metrics to weight the conservation value of the selected regions by both the phylogenetic diversity and range size of constituent species. High PE sites are those where species represent the largest fraction of evolutionary diversity, while also representing local rarity or endemicity.  Because PE provides a relative measure for comparing multiple sites, it is perfectly suited to our objectives. We will also use developments of abundance weighted evolutionary distinctiveness (AED) to simultaneously measure the conservation worth of individual species, multispecies sites, and multisite regions. In doing so, we can effectively estimate diversity across all species within a site, while also estimating distinctiveness at the species, population or individual level.

The resulting data data will enable us to apply to island systems a entirely new set of approaches recently derived from the so-called Neutral Theory of Biodiversity, and to assess how phylogenetic and functional diversity (feature diversity of plant species that can be extracted from trait databases already compiled by the participating teams) may vary across habitats within islands or among islands.

By explicit comparison to the BOLDSYSTEM database for microinvertebrates, a recent assessment of the Collembola fauna of Tenerife in the lab of BCE was able to determine that of 37 sampled putative native Collembola species to the island, 12 (32%) are in fact recent anthropogenic introductions. The demonstrated power of this approach to definitively characterise introduced and invasive species, that would otherwise remain undetected, is an important tool for biodiversity evaluation and valuation.