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  • Page | 22 Aug 2025
Connectivity of terrestrial protected areas

Information on the calculation of the Protected Connected (ProtConn) Land indicator

Biodiversity

Last updated | August 20, 2025

Indicator information

Name

Protected Connected (ProtConn) Land

Unit

Percentage of an area covered by protected connected lands

Area of interest

The indicator is distributed through REST services at country and ecoregion level and available in KCBD - Global Biodiversity Data Viewer (GBDV) at country level.

Related targets

biomon-prod-sdg-15
Sustainable Development Goal 15 on life on land
Target 3
Global Biodiversity Framework Target 3

Policy question

How well connected are the terrestrial protected area systems at the country and ecoregion level? This is a key question for measuring progress on the connectivity element of GBF Target 3 of the Convention on Biological Diversity (CBD).

Use and interpretation

The indicator can be used to assess:

  • The degree to which the spatial arrangement of Protected Areas (PAs) is successful in ensuring connectivity of protected lands.

  • How far countries or terrestrial ecoregions are from the connectivity element of GBF Target 3 of having 30% of the land covered by well-connected systems of PAs (Figure 1).

  • The contribution of different categories of land (protected, unprotected, transboundary) to the connectivity of PAs.

  • Where on the globe additional efforts are most needed in expanding or reinforcing the connectivity of PA systems.

  • Whether newly designated PAs provide effective connectivity gains in the PA system by acting as corridors or stepping stones between other PAs.

Figure 1. An example of a global assessment: Protected Connected land (% of ecoregion area) for the world’s terrestrial ecoregions as of January 2021 for a reference median dispersal distance of 10 km (Saura et al. 2017).
Figure 1. An example of a global assessment: Protected Connected land (% of ecoregion area) for the world’s terrestrial ecoregions as of January 2021 for a reference median dispersal distance of 10 km (Saura et al. 2017).

Key caveats

The current version of the connectivity indicator:

  • Assumes that PAs are effectively conserved and managed as to ensure sufficient connectivity levels that allow the successful movement of species through protected lands.

  • Does not consider the heterogeneity of the landscape matrix in between PAs, due to high variability in species responses; instead it aims at a more general assessment for the range of median dispersal distances observed for most terrestrial vertebrates (1 to 100 km). The reference dispersal distance of 10 km is the one used for the ProtConn indicator values shown in KCBD - GBDV.

Indicator status

Published in peer reviewed papers. The method regarding the connectivity at ecoregion level is described in Saura et al. (2017). The one describing the connectivity at country level is described in Saura et al. (2018).

The ProtConn indicator has been approved by the CBD as Component Indicator for the GBF Target 3. 

Available data and resources

Data

The KCBD Global Biodiversity Data Viewer provides the ProtConn values at the terrestrial ecoregion and country level for a reference species median dispersal distance of 10 km. Area-weighted averages at regional level are also provided.

Update frequency

Planned annually.

Code

All the connectivity indicators were calculated using GIS operations, R and the command line version of the software package Conefor 2.7 (Saura & Torné, 2009). 

Methodology

The indicator considers the spatial arrangement, size and coverage of protected areas (PAs), and accounts for both the land area that can be reached within PAs and that which is reachable through the connections between different PAs. The analysis includes all designated PAs in the WDPA (polygons and buffered points) not smaller than 1 km2, except UNESCO Biosphere Reserves, and is conducted for a range of median dispersal distances (1 to 100 km) observed for most terrestrial vertebrates. The indicator is calculated through network analysis, with the Probability of Connectivity and the Equivalent Connected Area as the underlying metrics. For more details see Saura et al. (2017, 2018, 2019). 

Input datasets

References

Dinerstein et al. (2017), An Ecoregion-Based Approach to Protecting Half the Terrestrial Realm, BioScience, Volume 67, Issue 6, June 2017, Pages 534–545, https://doi.org/10.1093/biosci/bix014

Saura, S. & J. Torné (2009). Conefor Sensinode 2.2: a software package for quantifying the importance of habitat patches for landscape connectivity. Environmental Modeling & Software, 24: 135-139. https://doi.org/10.1016/j.envsoft.2008.05.005

Saura, S. et al. (2017). Protected areas in the world’s ecoregions: How well connected are they? Ecological Indicators, 76: 144-158.  http://dx.doi.org/10.1016/j.ecolind.2016.12.047

Saura, S. et al. (2018). Protected area connectivity: Shortfalls in global targets and country-level priorities. Biological Conservation, 219: 56-67. https://doi.org/10.1016/j.biocon.2017.12.020

Saura, S., et al. (2019) Global trends in protected area connectivity from 2010 to 2018. Biological Conservation, 238: xx-xx. https://doi.org/10.1016/j.biocon.2019.07.028

UNEP-WCMC & IUCN (2025). Protected Planet: The World Database on Protected Areas (WDPA) [On-line], [January/2025], Cambridge, UK: UNEP-WCMC and IUCN. www.protectedplanet.net