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

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

3. 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)

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)

5. 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

6. 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 -

7. 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

8. 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-

9. 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

11. 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

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

13. 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)

14. 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

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

16. 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