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Range - concepts

Range - concepts. Ž elm í ra Ší pkov á & Brian Mac Sharry EEA – European Topic Centre on Biological Diversity (ETC/BD). Range - concept. natural range – biogeographical elements. range mapped as an occurrence in a grid. modeled statistical probabilities of occurrence.

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Range - concepts

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  1. Range - concepts Želmíra Šípková& Brian Mac Sharry EEA – European Topic Centre on Biological Diversity (ETC/BD)

  2. Range - concept • natural range – biogeographical elements • range mapped as an occurrence in a grid • modeled statistical probabilities of occurrence

  3. Range in EU reporting obligations • The concept was defined originally for the Article 17 reporting taking into account experience from the previous round reporting (the need of comparable and standarised approach) • The principal aim is toevaluate status of habitats and species (calculate trends of an overall distribution and based on agreed thresholds draw a conclusion) • A single approach for wide variety of species plus habitat types, for variety of situation (e.g. expert judgment)

  4. Range calculation – range tool DISTRIBUTION presence/absence in a grid (10x10km) RANGE – an envelope around the distribution (IUCN Red List concept) • MS and EU scale (relatively tight envelope) • range can contain discontinuities • standard, repeatable procedure

  5. Range calculation – range tool DISTRIBUTION presence/absence in a grid (10x10km) RANGE – an envelope around the distribution (IUCN Red List concept) range tool • MS and EU scale assessment (relatively tight envelope) • range can contain discontinuities • standard, repeatable procedure

  6. Range calculation • calculation of range = filling in the gaps in the distribution to create range envelope(s) • 2001-2006 Article 17 guidelines possible gaps in the range envelope (areas of unsuitable conditions without occurrence of habitat/species larger than 40-50km)

  7. Range – gap distance • a distance between two distribution points which are connected to create a polygon • a gap distance determines resulting range • 40-50km in reporting guidelines

  8. Gap distance

  9. Range calculation STEPS: 1) filling in the gaps in the distribution to create range envelope(s) lines between 2 grid cells if distance between their centroids is equal or lower to defined value

  10. Range calculation STEPS: 1) filling in the gaps in the distribution to create range polygon(s) analyses where set of lines form a polygon includes grid cells from the reference grid file, which are intersected by created lines and polygons into a range

  11. Range calculation STEPS: 1) filling in the gaps in the distribution to create range polygon(s) 2) fitting to the environmental variables – excluding inappropriate areas from range polygons

  12. Range calculation STEPS: 1) filling in the gaps in the distribution to create range polygon(s) 2) fitting to the environmental variables – excluding inappropriate areas from range polygons

  13. Range calculation STEPS: 1) filling in the gaps in the distribution to create range polygon(s) 2) fitting to the environmental variables – excluding inappropriate areas from range polygons 3) manual modification/ correction

  14. Range calculation STEPS: 1) filling in the gaps in the distribution to create range polygon(s) 2) fitting to the environmental variables – excluding inappropriate areas from range polygons 3) manual modification/ correction

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