# Essential Biodiversity Variables

Essential Biodiversity Variables (EBVs) is a putative set of parameters intended to be the minimum set of broadly agreed upon necessary and sufficient biodiversity variables for at least national to global monitoring, researching, and forecasting of biodiversity. They are being developed by an interdisciplinary group of governmental and academic research partners. The initiative aims for a harmonised global biodiversity monitoring system. EBVs would be used to inform biodiversity change indicators, such as the CBD Biodiversity Indicators for the Aichi Targets.
The concept is partly based on the earlier Essential Climate Variables. It can be generalised as the minimum set of variables for describing and predicting a system's state and dynamics. Areas with more developed EV lists include climate, ocean, and biodiversity.

## EBV Classes / Categories

The current candidate EBVs occupy six classes of Essential Biodiversity Variable: genetic composition, species populations, species traits, community composition, ecosystem structure, and ecosystem function. Within each class are a few to several variables.
| EBV Class | EBV | Notes |
| Genetic composition | Co-ancestry | |
| Genetic composition | Allelic diversity | |
| Genetic composition | Population genetic differentiation | |
| Genetic composition | Breed and variety diversity | |
| Species populations | Species distribution | Addressed in. Track from space. |
| Species populations | Population abundance | Addressed in. |
| Species populations | Population age / size structure | |
| Species traits (subject of) | Phenology | Track from space. GlobDiversity RS-enabled EBV (land surface phenology). |
| Species traits (subject of) | Body mass | Vegetation height—track from space. |
| Species traits (subject of) | Natal dispersal distance | |
| Species traits (subject of) | Migratory behaviour | |
| Species traits (subject of) | Demographic traits | |
| Species traits (subject of) | Physiological traits | Track from space. GlobDiversity RS-enabled EBV (canopy chlorophyll concentration). |
| Community composition | Taxonomic diversity | |
| Community composition | Species interactions | |
| Ecosystem function | Net primary production | Track from space. |
| Ecosystem function | Secondary production | |
| Ecosystem function | Nutrient retention | |
| Ecosystem function | Disturbance regime | Track from space. Should not be a candidate EBV, due to being non-biological in nature. |
| Ecosystem structure | Habitat structure | |
| Ecosystem structure | Ecosystem extent and fragmentation | Track from space. GlobDiversity RS-enabled EBV (fragmentation). |
| Ecosystem structure | Ecosystem composition by functional type | |

## Associated projects and organisations

As of 2017, participants in the project consist of the GlobDiversity project (funded by the European Space Agency) under GEO BON (Group on Earth Observations Biodiversity Observation Network; a cooperative project of international universities), and the GLOBIS-B project (Global Infrastructures for Supporting Biodiversity Research; funded by the EU Horizon 2020 programme).

## Development

The concept was first proposed in 2012 and developed in the following years.
The GLOBIS-B global cooperation project, aimed to advance the challenge of practical implementation of EBVs by supporting interoperability and cooperation activities among diverse biodiversity infrastructures, started in 2015. The GlobDiversity project of GEO BON, led by the University of Zurich, started in 2017, focusing on specification and engineering of three RS-enabled EBVs.
The scope and screening of potential variables is under ongoing discussion.
This includes definition of the species distribution EBV and population abundance EBV, operationalisation of the EBV framework, data and tools for building EBV data products, workflow for building EBV data products, metadata and data sharing standards; and possible integration of abiotic variables (e.g. those emphasised in the Ecosystem Integrity framework) with biotic variables (emphasised in the EBV framework) to achieve comprehensive ecosystem monitoring.
"EBV data products" refers to the end product in the EBV information supply chain, from raw observations, to EBV-usable data, to EBV-ready data, to EBV data products. Each of these three types of EBV datasets could be used to produce indicators. Data sources for EBVs are categorised into four types: extensive and intensive monitoring schemes, ecological field studies, and remote sensing. Each have their own often complementary properties, implying that data integration will be important for creation of representative EBVs, as well as identifying and filling data gaps.