This is the first heat map for the Big Biodiversity Layer. This heat map corresponds to the OECM biodiversity value "Rare, threatened or endangered species and habitats, and the ecosystems that support them, including species and sites identified on the IUCN Red List of Threatened Species, Red List of Ecosystems, or national equivalents". Species and habitats which contribute to this layer were chosen based off of red lists, and other relevant Scottish or British lists, and weighted accordingly.
The methodology uses a 1km x 1km grid across Scotland. Each species and habitat present in each grid square contribute to a final score for that grid square with their assigned weighting. Weights are added up for all species and habitats present in each square, only contributing to the value once if present, but a lack of presence for any species/habitat does not detract from the final score for a grid square. This gives each grid square a numeric value which relates to the contribution from that area to the corresponding biodiversity value.
The BBL is going to be one tool which helps to inform decisions around 30x30, along with other tools and ground truthing of BBL outputs. It will provide a starting point, indicative of where we should explore for land which could potentially contribute to 30x30. This is caveated by data availability. If a BBL map shows an area of land to be contributing to a biodiversity value, then this is because the data is available for this land, and at some point the area has had attributes (species/habitats/other relevant data) which make it good for said biodiversity value. This indicates that areas could be good for this biodiversity value, and that an area should then be explored to realise this potential. On the flipside of this, are areas which do not come out as strong for a given biodiversity value. This would indicate that there is no data to suggest that this area contributes to the biodiversity value, but doesn't mean that it has no biodiversity value. There could be good biodiversity in the area, but a lack of surveys/visitors recording data, and thus it doesn't come out as high value on the BBL. These caveats should be kept in mind when using the BBL, and it should be used as a tool to inform decisions along with other evidence, and not alone.