
Introduction
The proposed indicator provides a summary of current within-species genetic diversity, as measured by the proxies of in situ and ex situ records (based e. g. on specimen and observation data), distribution range extent, ecoregion coverage and monitoring efforts.
Thereby, it provides a measure for the draft Monitoring Element “Trends in the diversity of wild species” associated with the draft Component of the 2050 Goal A5 “Maintain genetic diversity”. The indicator has high relevance for Goal A5 and Target 19, as well as, Aichi Target 13 and SDGs 14 & 15.
Methodological outline of the index:
- Calculate per species (taxon):
- Identify the current known or estimated distribution range of each species
- using national species lists, that is, defining as distribution range all countries, in which the species occurs in their national species lists (cp. the indicator “Completeness of the world’s species catalogue” of CETAF and SPNHC)
- using species distribution models, estimating species’ distribution ranges from publicly available collections data (cp. the Comprehensiveness of conservation of socioeconomically as well as culturally valuable species Index)
- Identify the ecoregions that are present within the identified distribution range of each species
- Record presence/absence of species collections or records within each of the ecoregions for each country or administrative unit present in its distribution range. Collection data is provided by publicly available repositories, as for example, GBIF, INSDC, BOLD and similar accumulators of specimen and record information
- A specimen collected, individual observed, meta-barcode detected or environmental DNA monitored is used as a proxy for the presence of the species at the recorded location
- In some cases, it might be reasonable to require two or more records per spatial entity (ecoregion, administrative unit, etc.)
- Relate the recorded presences of a species to the maximum number possible, counted per administrative units, that is,
- all of its currently known distribution range and ecoregions
- as part of a time-series also its historically known distribution range
- its habitable ecoregions based on expert knowledge
- Take the number of records available, over all and per monitoring time interval, into account as a measure of monitoring efforts per country or administrative units
- Identify the current known or estimated distribution range of each species
- Sum over all species and countries (spatial administrative entities) for a single global value
- sum first over all species to obtain overall national indexes (more general: indices for spatial entities at subnational to regional levels)
- sum first over countries to obtain a global index per species or a set of species (eg. forest-associated species, marine species, wild-relatives of cultivated or culturally important species)
- A time-series of the index arises by repeated calculation of the index using new, current datasets at specified time intervals, informing on trends per species, spatial area and of overall global genetic diversity
- Moreover, the continuing digitization of collection records provides the foundation for reconstructing the historical tail of trends back in time.
- In addition, the extent of a species’ within-species genetic diversity that is under protection can be calculated based on its presence at sites with a protection status per ecoregion and administrative unit. For this purpose, global datasets on protected areas (e. g. https://www.unbiodiversitylab.org/) are added to and evaluated in the workflow (cp. the “Comprehensiveness of conservation of socioeconomically as well as culturally valuable species” indicator below).
Background information
The proposed indicator is similar to the currently operational and included Biodiversity Indicators Partnership-indicator “Comprehensiveness of conservation of socioeconomically as well as culturally valuable species”. This indicator is provided by CIAT and Crop Trust. It also takes inspiration from EUFORGEN’s pan-European strategy for the conservation of forest trees (2015) and its recently published set of indicators (2020).
The indicator is based on publicly available data from GBIF, INSDC, BOLD and similar data aggregators, the IUCN-based global classification of ecoregions or comparable classifications, and a global list of species, for which data sources include GBIF, INSDC and BOLD records (see the indicator “Completeness of the world’s species catalogue” proposed by SPNHC and CETAF).
The calculation of the index should be cost-effective, since no new, additional datasets need to be built. Main efforts associated with maintaining and calculating the index are related to data research and dataset assembly, as well as, data cleaning.
The information content of the indicator will depend on the number and global coverage of available records and, thus, the participation in monitoring efforts for biodiversity, as well as, on our knowledge of species and their distributions.
The indicator provides a minimum estimate of conserved within-species genetic diversity.
The baseline of the indicator is its first year of implementation. However, the historical tail of the time-series can be reconstructed back to the date of the earliest record present in publicly accessible repositories, as for example GBIF, INSDC and BOLD.
The indicator can be aggregated and disaggregated as needed to and from sub-national, national, regional and global levels.
Furthermore, it is possible to disaggregate the indicator based on the minority status, gender and age of the record provider, as found in the metadata associated with the publicly available records in e. g. GBIF. Such a disaggregation will inform about the participation and contribution of indigenous peoples and local communities (IPLC), women, girls and youth to our knowledge of within-species diversity. These contributions express their will and action towards “equitable involvement in decision-making related to biodiversity” and for ensuring “rights over relevant resources of indigenous peoples and local communities, women and girls, as well as, youth” (Target 20).