Biodiversity monitoring is the repeated observation or measurement of biological diversity to determine its status and trend.
Monitoring thus contrasts to surveys, in which biodiversity is measured at a single point in time, e.g. to determine the current distribution of a species. To understand the causes for change in status and trends, biodiversity monitoring must also cover measurements of environmental pressures.
Because of the complexity of biodiversity, incomplete taxonomic knowledge, and high cost of total biodiversity assessments, monitoring relies on indicators. The biodiversity indicators being monitored may be qualitative (e.g. presence or absence of an indicator species) or quantitative (abundance or population density of a species, distribution area of a habitat, number of typical species in the habitat, etc.).
Biodiversity monitoring is an obligatory component in many international agreements. The Convention on Biological Diversity obliges each contracting party, 'as far as possible and as appropriate', to 'identify components of biological diversity important for its conservation and sustainable use ..., to 'monitor, through sampling and other techniques, the components of biological diversity identified' ..., as well as to 'identify processes and categories of activities which have or are likely to have significant adverse impacts on the conservation and sustainable use of biological diversity, and monitor their effects through sampling and other techniques' (Art. 7).
In the European Union, biodiversity monitoring is also explicitly included in many policy documents, such as the European Environmental Action plan, the European Biodiversity Strategy, and the 2010 target of halting the loss of biodiversity. Most importantly, the Habitats and Birds Directives legally bind Member States to monitor biodiversity.
In the EuMon project, the focus is limited to the monitoring of two main components of biodiversity: species and habitats. For these main components, various properties may be monitored, e.g., trends in populations, distribution, community composition, habitat quality etc. The observations may be based on the collection of data on presence/absence, counts, mark-recapture data, population composition, phenology and other measures. In order to allow reliable inferences a sound statistical sampling design and appropriate analytical methods should be employed. Such aspects of biodiversity monitoring are covered by the EuMon project. The BioMAT tool provides support for the design and analysis of biodiversity monitoring.
An overview of European biodiversity monitoring schemes in Europe has been assembled by the EuMon project. The information is organised in a database (DaEuMon) that may be consulted via module 1 of BioMAT.