The monitoring of species and habitats is essential to biodiversity conservation. Although guidelines for biodiversity monitoring have been published since at least 1920, we know little on current practices in existing monitoring programmes. To fill this gap, we collected metadata on 646 species and habitat monitoring programmes in Europe and characterised current practices in monitoring. We developed metadata-based indicators for sampling design, sampling effort and data analysis to evaluate current practices, to study the importance of socio-economic factors in monitoring and to provide benchmarks for the comparison of programmes.
We find that the starting year, motivation, funding source and geographic scope of monitoring influenced at least one of the indicators in both species and habitat based programmes. More specifically, sampling design scores varied by funding source and motivation in species monitoring and decreased with time (starting year) in habitat monitoring. Sampling effort decreased with time in both species and habitat monitoring and varied by funding source and motivation in species monitoring. Finally, the frequency of using hypothesis-testing statistics was lower in species monitoring than in habitat monitoring and it varied with geographic scope in both. The perception of the minimum change detectable by the programme (‘precision’) matched spatial sampling effort in species monitoring but was rarely estimated in habitat monitoring.
We conclude that there are many signs of promising developments in biodiversity monitoring but also that there are options for improvement in sampling design, sampling effort and data analysis. Our results thus partially confirm recent concerns over the quality of biodiversity monitoring programmes. Although monitoring programmes differ greatly in their objectives, our general indicators provide benchmarks for the comparison of programmes that can be used to identify strengths and weaknesses in individual monitoring programmes. This knowledge then can be used to improve current practices, design new monitoring programmes, identify best practices and standardise performance across monitoring programmes. For more details, please see  and references therein.
 Lengyel Sz, Kosztyi B, Schmeller DS, Henry P-Y, Kotarac M, Lin Y-P, Henle K. 2018. Evaluating and benchmarking biodiversity monitoring: Metadata-based indicators for sampling design, sampling effort and data analysis. Ecological Indicators 85: 624-633.