Essential Biodiversity Variables

Cleared hills into the distance

Former montane forest on Mbeya Peak, Tanzania, image by Ana Claudia Araujo 

How should we study biodiversity change?

In an ideal world, we would study many different aspects of biodiversity and how they change over time. This would allow us to distinguish between natural ecological and evolutionary change and those changes brought about by human impacts. But, time and data constraints mean we can only look at certain aspects of biodiversity.

Which aspects of biodiversity should we study and how will these change? 

What are Essential Biodiversity Variables? 

Biodiversity scientists have proposed a set of core variables that will collectively show the effect of anthropogenic change on biodiversity.

These are similar to studies of global climate system where the world’s climate scientists agreed on a set of core variables that would collectively show the effect of global climate change, known as Essential Climate Variables.

We should study those aspects that are essential to reveal variation to the world’s biodiversity. 

This work has been co-ordinated by the Group on Earth Observations Biodiversity Observation Network (GEO BON), soliciting the input and views of a wide range of experts in different fields of biodiversity measurement from around the world. 

Plants Under Pressure

Find out more about the Plants Under Pressure project

Museum staff

The Essential Biodiversity Variables will be used to track progress towards:

Six classes of Essential Biodiversity Variables

An initial list of Essential Biodiversity Variables has been refined through extensive consultation and discussion, and are grouped into six classes:

  • genetic diversity
  • population abundance
  • functional diversity
  • community composition
  • ecological structure
  • ecological function

The Essential Biodiversity Variables themselves represent an intermediate layer in between the data collected and the indicators that reveal trends in biodiversity change over time. 

To use an analogy, Essential Biodiversity Variables are like the share price in a biodiversity stock market that measures the value of many different aspects of biological diversity. The Essential Biodiversity Variables are what varies over time.

A conceptual framework of biodiversity change

Essential Biodiversity Variables form a useful conceptual model of the breadth of biodiversity and the ways it is changing. This model reveals that current biodiversity targets and their indicators mostly focus on a few Essential Biodiversity Variables, while other Essential Biodiversity Variables are poorly represented by internationally-agreed conservation policies. Also, certain Essential Biodiversity Variables are particularly suited to identifying very rapid changes in biodiversity.

Funded by the 7th Framework Programme of the European Union.


Schmeller, D.S., L.V. Weatherdon, A. Loyau, J.-B. Mihoub, N.A. Brummitt, A. Bondeau, L. Brotons, Y. Gavish, I.R. Geijzendorffer, P. Haase, M. Kümmerlen, C. Martin, C.J. Marsh, D. Rocchini, H. Saarenmaa, S. Stoll & E. Regan, 2018. A suite of Essential Biodiversity Variables for detecting critical biodiversity change. Biological Reviews 93(1): 55–71. doi: 10.1111/brv.12332.

Pereira, H.M., J. Belnap, M. Böhm, N. Brummitt, J. Garcia-Moreno, R. Gregory, L. Martin, C. Peng, V. Proença, D. Schmeller & C. van Swaay, 2017. Monitoring Essential Biodiversity Variables at the Species Level. Pp. 79–105 in M. Walters & R.J. Scholes (eds.) The GEO Handbook on Biodiversity Observation Networks, Springer International Publishing. doi: 10.1007/978-3-319-27288-7_4.

Brummitt, N.A., E.C. Regan, L.V. Weatherdon, C. Martin, I.R. Geijzendorffer, D. Rocchini, Y. Gavish, P. Haase, C.J. Marsh, D.S. Schmeller, 2016. Taking stock of Nature: Essential Biodiversity Variables explained. Biological Conservation 213: 252–255.

Proença, V., L.J. Martin, H.M. Pereira, M. Fernandez, L. McRae, J. Belnap, M. Böhm, N. Brummitt, J. García-Moreno, R.D. Gregory, J.P. Honrado, N. Jürgens, M. Opige, C. Peng, D.S. Schmeller, P. Tiago &  C.A.M. van Swaay, 2016. Global biodiversity monitoring: from data sources to Essential Biodiversity Variables. Biological Conservation 213: 256–263.

Geijzendorffer, I.R., E. Regan, H.M. Pereira, L. Brotons, N.A. Brummitt, Y. Gavish, P. Haase, C.S. Martin, J.-B. Mihoub, C. Secades, D.S. Schmeller, S. Stoll, F.T. Wetzel & M. Walters, 2015. Bridging the gap between biodiversity data and policy reporting needs: an Essential Biodiversity Variables perspective. Journal of Applied Ecology 53(5): 1341–1350; doi: 10.1111/1365-2664.12417.

Pereira, H.M., S. Ferrier, M. Walters, G.N. Geller, R.H.G. Jongman, R.J. Scholes, M. W. Bruford, N. Brummitt, S.H.M. Butchart, A.C. Cardoso, N.C. Coops, E. Dulloo, D.P. Faith, J. Freyhof, R.D. Gregory, C. Heip, R. Höft, G. Hurtt, W. Jetz, D. Karp, M.A. McGeoch, D. Obura, Y. Onoda, N. Pettorelli, B. Reyers, R. Sayre, J.P.W. Scharlemann, S.N. Stuart, E. Turak, M. Walpole, M. Wegmann, 2013. Essential Biodiversity Variables for global earth observation. Science 339 (6117): 277–278.


Plants Under Pressure projects

Plants Under Pressure

Assessing threats to plants and monitoring the state of the plant world.

Bryophytes (mosses, liverworts and hornworts)

We have assessed 1021 species of bryophytes from around the world using the IUCN Red List Criteria, a ten-fold increase.

Hotspots of plant diversity

Expeditions to areas of high plant diversity help us to ensure that our IUCN Red List assessments are accurate.

Comparing plant diversity indicators

Can we detect small-scale changes to biodiversity?

Simulating plant diversity change

How might plant diversity respond to changing situations in the future?

Pteridophytes (ferns, lycophytes and their allies)

We have tripled the number of species of pteridophytes assessed using the IUCN Red List Criteria.