Biodiversity Blending at Bangor
Restoration Story by Anna Wood and Simon Creer
Identifying which insects live where in forests can help us study how biodiversity in forests changes. This is what our SUPERB team at Bangor University is working on. Our partners from the SUPERB demo sites in Spain, France, Sweden, Czech Republic, Romania and Serbia collected over 1,600 arthropod samples over the last three spring/summer seasons and sent them to the Molecular Ecology and Evolution group at Bangor University in the UK.
To find out which insects live in our demo sites, we need to capture and identify a representation of the insect community that live in an area of a forest. One method of doing this is using a Malaise trap (see picture above). It looks like a tent, and its function is to trap flying insects and direct them into a bottle of ethanol that preserves them. It is possible to identify some of the insects from their physical appearance, but many insects are difficult to identify just by looking at them, but they can be identified from the DNA present in their bodies.
DNA Barcoding and Metabarcoding of “Insect Soup”
DNA barcoding takes advantage of the fact that many species have genes that are more similar within a species than between species. These variable regions, or ‘DNA barcode’ regions, are often sandwiched in between more conserved regions of the genome. Using molecular biology, we can use the conserved regions and amplify the barcode region using a technique called PCR (the polymerase chain reaction), from which we can generate a DNA sequence. This sequence can become a DNA barcode for each species, forming a global reference library of barcodes that can be used for species identification. DNA metabarcoding follows the same theory, but instead of using DNA from one individual or one sequence, it uses DNA from the whole communities of different species to generate millions of sequences.
The first step is to homogenise or blend the entire mixed insect sample into an “insect smoothie.” From this, it’s possible to extract DNA from all the different insects, which can be PCR’ed sample by sample and sequenced all together using high-throughput sequencing. When the sequences are compared to the DNA barcoding reference library, we can identify which insect species are found in our forests. Metabarcoding can be used for many different sample types, and in SUPERB, we are also using it to identify fungi, plants and microscopic animals’ species from soil samples collected in the same forests.
Over the last 3 years we have blended over 1600 malaise insect samples, which involved washing over 3200 blender cups. The metabarcoding laboratory work for all the SUPERB project samples is now complete and currently being sequenced.
We will be analysing the insect metabarcoding data, along with soil metabarcoding and other datasets collected at the same forest sites, to explore the above and below ground biodiversity in Europe’s forests. We hope to have exciting data to share soon, and we’ll be take a well-earned break from making insect smoothies until next time!
