Population size units (Art. 17) Jean Ichter, Expert Group on Reporting, Brussels, 18 October 2016 Population size units (Art. 17)

Population size units Evolution of population size reporting (long story short) 2001-06: the choice of population unit for reporting report was left to the Member States 2007-12: the Member States where asked to use of individuals except for a relatively short list of species + an optional alternative unit

Art. 17 reporting format asks for: Population size units Art. 17 reporting format asks for: Population size in the reporting unit (for EU biogeographical assessments and other EU or biogeographical statistics) (field 6.2) Additional population size, using population size unit other than reporting unit, e.g. the unit used for assessment at national level (field 6.4)

Population size units Population size in the reporting unit for all species will be reported using either : individuals number of occupied 1 x 1 km grids (Note: except for species restricted to a single country)

Population unit: number of occupied 1 x 1 km grids Population size units Population unit: number of occupied 1 x 1 km grids Spatial surrogates for population size when technically robust methods for estimating species population size do not exist or they are excessively costly

Population size units Species growing in dense stands or forming colonies where individuals cannot be easily visually separated e.g. aquatic plants, bryophytes, coral; Source: Rob Felix - http://eunis.eea.europa.eu/species/185649

Population size units Species occurring in defined sites where it is difficult, dangerous or very expensive to collect good population data, such as ponds, fens, single trees or cliffs. Source : Jean Ichter

Population size units Plant species listed in Annex V of the Habitat Directive as experience shows there is a lack of information available on population size Source Hans Dekker- http://eunis.eea.europa.eu/species/153665

Population size units Species growing in dense stands or forming colonies where individuals cannot be easily visually separated e.g. aquatic plants, bryophytes, coral; Species occurring in defined sites where it is difficult, dangerous or very expensive to collect good population data, such as ponds, fens, single trees or cliffs. Plant species listed in Annex V of the Habitat Directive as experience shows there is a lack of information available on population size

Population size units Mammals Bats (Chiroptera) 15 March 2016: individuals for all mammals 11 July 2016: revised version submitted for comments Last round of comment: Indiv. for cave dwelling bats (DE, ES, IT, PT / HR) Source: Jean Ichter

Population size units Mammals Bats (Chiroptera) Small mammals (exceptions) Soricidae, Gliridae, Mustelidae Comments on Microtus cabrerae (ES), Dinaromys bogdanovi (HR)

Monitoring or assessment of the species status Population size units If Reporting unit ≠ Monitoring or assessment of the species status Conversion of the population size estimated in the local units (monitoring and assessment)

Population size units Proposed guidance for converting local units into 1 x 1 km grids The monitoring unit involves point data Each 1x1 km grid in which a point occurs should be counted, in this case 5 grids The monitoring unit involves polygon data Only 1x1 km grid covered by 50% or more of the polygon should be counted, in this case 4 grids The monitoring unit is a linear feature Each 1x1 km grid in which a segment of the linear feature occurs should be counted, in this case 5 grids

Population size units Proposed method for converting distribution to number of occupied 1 x 1 km grids 8km grid square 1km grid square

Population size units Next steps: End. 2016: MS provide exceptions for population units (feedbacks from MS) April 2017: final guidelines + Art. 17 checklist with population units