Preserving and restoring biodiversity requires characterising and conserving species genetic biodiversity. Indeed, insufficient levels of genetic diversity can lead to species decline and, ultimately, extinction. Adopted in 2022, the Kunming-Montreal Global Biodiversity Framework (GBF) is a UN Convention of Biological Diversity (CBD) strategy. It is the first of the latter to focus on protecting the genetic diversity of all wild and domesticated species, with a view to ensuring their long-term viability. Starting in 2026, the GBF’s 196 signatories, including France and the EU, will have to submit progress reports on their efforts to conserve species genetic diversity. To facilitate this task, an international scientific consortium has developed two genetic diversity indicators that can be estimated using population-level data 1 , which may or may not be based on DNA. These indicators were evaluated via peer review and were adopted for use by the GBF. To evaluate the feasibility of employing these indicators with populations of wild species, researchers carried out a broad-scale test in nine countries with a range of biodiversity levels and socioeconomic conditions: Australia, Belgium, Colombia, France, Japan, Mexico, South Africa, Sweden, and the US.
Exploiting existing population-level data
All living species comprise one or more geographically distinct populations. Across the 9 study countries, researchers estimated the genetic diversity indicators for 919 species of animals, plants, and fungi, using data from a total of 5,271 populations. They employed currently available data, such as population counts, geographical distributions, demographic surveys, and DNA, to estimate the first indicator-the percentage of a species’ populations that are large enough (~5,000 individuals, on average) to maintain their genetic diversity, thereby ensuring long-term viability. The researchers also estimated a second indicator: the percentage of a species’ populations that have been maintained.Among the species assessed, 53% have maintained all their populations. Of greater concern is that, for 58% of species, not a single one of their populations is large enough to sustain its genetic diversity. Only 19% of species are in a situation where all their populations are sufficiently large. To illustrate these findings, we can use the capercaillie, a wild bird that is a protected species in France. The researchers found that two of the capercaillie’s populations have disappeared and that, of the remaining four, only one population is large enough to sustain its genetic diversity. In the case of Angelica heterocarpa, an estuary plant endemic to France, all four of the species’ populations have been maintained, but only two are large enough to sustain their genetic diversity.
Implementation-ready indicators
The utility of these indicators is that they are standardised and can be applied by all countries to all species. There is no need for DNA-based data or special research infrastructure. Indicator values can be calculated using existing estimates of population numbers or sizes. Even approximations can suffice (e.g., less than 1,000, several thousand). These data can be gleaned from a variety of sources, such as research reports, public research databases, NGOs, knowledge held by local stakeholders, and citizen science programmes. The main resource requirement is a reliable workforce, ideally composed of individuals versed in biodiversity management, that can gather the requisite information. It takes around 400 hours of work to compile the data for 100 species.The study’s take-home message is that, based on the genetic diversity indicators, most of the species assessed are at risk. It is thus essential that these indicators be used to inform efforts aimed at protecting biodiversity. The researchers’ next step is to work with local and national stakeholders (e.g., representatives from the Ministry of Ecological Transition and the National Biodiversity Observatory, managers of national parks) to organise workshops to facilitate indicator usage.
[ 1 ] A population is a group of organisms of the same species that live in the same geographical area and that are capable of interbreeding.
REfErences
Mastretta-Yanes A., da Silva J M. et al. (2024) Multinational evaluation of genetic diversity indicators for the Kuming-Montreal Biodiversity Framework. Ecology letters DOI : https://doi.org/10.1111/ele.14461
Policy brief issued by the Coalition for Conservation Genetics: Genetic diversity indicators for the Global Biodiversity Framework