Ten Brink, 2006; Kleijn et al., 2006) to the use of proxies (Alliance Environnement, 2017) or models (Kok et al., 2018). In this frame, there is, overall, a lack of data recorded through monitoring efforts, EU wide assessments are in fact presently relying on a limited set of surveyed data: farmland birds (Gregory et al., 20056), grassland butterflies (EEA, 2013a) and the reporting under the Birds and Habitats Directive (EC, 2015).
Biodiversity decline, and in particular the loss of genetic diversity, is within the nine global-scale processes that are essential to maintain the earth system in a resilient and accommodating state defined by Steffen et al. (2015), one of the two processes laying outside the safe operating space. Despite the urgency to revert the trend and the efforts from the policy side to incorporate the concern, signals are not encouraging (EC, 2020). Better targeting and improved assessments need filling knowledge gaps and using updated and detailed data, covering different taxa. Moreover, in the frame of planning, implementing, monitoring and assessing EU policy, sources of information should cover the entire European Union, and should be based on a harmonized approach for data collection. Establishing surveys is an important way to guarantee that such information becomes available.
The EU Biodiversity Strategy to 2020 defines biodiversity as ‘the unique variety of life on our planet’, the UN Convention on Biological Diversity as ‘the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems’ (UN, 1993). Such definitions suggest a complexity that is probably the reason why it has been so difficult to put in place a large-scale monitoring system that includes surveys of the main components of biodiversity. Surveys can be burdensome and therefore the costs can exceed current financial and administrative capacity, especially when an entire continent should be covered. Nevertheless, initiatives and pilots are ongoing, to enlarge the available data pool.
This chapter reviews where we stand in surveying biodiversity in agricultural areas at the EU level as well as plans to increase monitoring efforts. The sections that follow describe established surveys, ongoing pilots and plans for new surveys at the EU scale. A multiplicity of information is available at local/regional/national scale, but this chapter focusses on the long and winding road to wall-to-wall coverage of the European Union. At the end, the point can be made on where we will stand in the short-medium term with our knowledge of agro-biodiversity in the European Union, and which gaps still need to be filled to appropriately and sufficiently describe biodiversity dynamics.
2Farmland birds and butterflies
2.1 The Pan-European common bird monitoring scheme
Many countries of the European Union are characterized by a long-lasting tradition of bird-watching, on which scientifically grounded countrywide surveys were nested. Countries such as Finland, Sweden and Denmark organized a countrywide monitoring scheme in 1975, the United Kingdom in the 1960s. Others started later on, but nowadays all EU countries except Malta have a monitoring scheme in place.
In 2002, the Pan-European Common Bird Monitoring Scheme (PECBMS) was started as a joint initiative of the European Bird Census Council (EBCC) and BirdLife International, with the aims of: collecting data on European common bird species from national monitoring schemes and calculate European common bird indices and indicators, to raise awareness and to feed the policy process; support the national coordinators in setting up the schemes, and guarantee a harmonized approach in the calculation of the indices; explore the relation between population trends and main driving forces (EBCC, 2019).
Most surveys are carried out through point or line transect counts, where the selection of the plots to be surveyed (each plot containing one or more point or transect) is made either following rigorous statistical procedures (e.g. systematic selection, stratified random selection) or a free choice approach (Table 1). The surveyor visits the assigned location one or more times during the year, in predetermined time windows (e.g. 10 May–20 June as in the Italian survey), and records the individuals seen or heard. A thorough statistical analysis is followed to identify errors and outliers.
Table 1 Principal characteristics of national breeding birds monitoring schemes
| Country | Generic breeding bird monitoring scheme | Contributes to PECBMS | Start year | Field survey methods | Selection of plots | Number of species |
| Austria | Yes | Yes | 1998 | Point counts | Free choice | 85 |
| Belgium | Yes | Yes | 1990 | Point counts | Stratified random, other | 134 |
| Bulgaria | Yes | Yes | 2004 | Line transects | Stratified random | 63 |
| Croatia | Yes | Not yet | 2015 | Point counts | Stratified semi-random | 30 |
| Cyprus | Yes | Yes | 2006 | Line transects | Other | 45 |
| Czech Republic | Yes | Yes | 1982 | Point counts, line transects | Free choice, stratified random | 218 |
| Denmark | Yes | Yes | 1975 | Point counts | Free choice | 143 |
| Estonia | Yes | Yes | 1983 | Point counts | Free choice | 90 |
| Finland | Yes | Yes | 1975 | Point counts, line transects, other | Systematic, other | 140 |
| France | Yes | Yes | 1989 | Point counts | Other | 150 |
|
Germany
|
