Just ten percent of the global terrestrial protected area network is structurally connected via intact land

Abstract

Land free of direct anthropogenic disturbance is considered essential for achieving biodiversity conservation outcomes but is rapidly eroding. In response, many nations are increasing their protected area (PA) estates, but little consideration is given to the context of the surrounding landscape. This is despite the fact that structural connectivity between PAs is critical in a changing climate and mandated by international conservation targets. Using a high-resolution assessment of human pressure, we show that while ~40% of the terrestrial planet is intact, only 9.7% of Earth’s terrestrial protected network can be considered structurally connected. On average, 11% of each country or territory’s PA estate can be considered connected. As the global community commits to bolder action on abating biodiversity loss, placement of future PAs will be critical, as will an increased focus on landscape-scale habitat retention and restoration efforts to ensure those important areas set aside for conservation outcomes will remain (or become) connected.

Ecological corridors for the amphibians and reptiles in the Natura 2000 sites of Romania

“…However, through their intrinsic characteristics, amphibians and reptiles make very good model organisms for connectivity analyses 65,70 . The landscape linkages obtained in this study raise the alarm on the fact that the complex network of sites created through the Natura 2000 program does not function like a system; there are sites and species that cannot be connected through areas of natural habitat, so these sites are of utmost importance and should be prioritized for conservation 78 . Some of the species that had low connectivity or no connectivity (e.g.…”

“…We had multiple reasons in choosing this approach. Foremost, natural habitats have exceptional value for both connectivity and biodiversity 78,79 -they maximize animal mobility, contain higher taxonomic diversity, higher genetic diversity, and meta-population retention, thus represent refugia for biodiversity. In contrast, areas impacted by human activities are viewed as unlikely to hold sufficient connectivity value for many key elements of biodiversity 78 .…”

“…Foremost, natural habitats have exceptional value for both connectivity and biodiversity 78,79 -they maximize animal mobility, contain higher taxonomic diversity, higher genetic diversity, and meta-population retention, thus represent refugia for biodiversity. In contrast, areas impacted by human activities are viewed as unlikely to hold sufficient connectivity value for many key elements of biodiversity 78 . Human-modified landscapes are also susceptible to frequent land use changes, one of the primary sources of decline for both amphibians and reptiles 55,80,81 .…”

“…Human-modified landscapes are also susceptible to frequent land use changes, one of the primary sources of decline for both amphibians and reptiles 55,80,81 . It is generally agreed that avoiding degradation of existing habitat is a better strategy than restoration, as the latter implies increased costs and is unlikely to lead to full recovery 78,82 ; corridors generally imply substantial financial efforts and, as a result, their implementation has been met with resistance throughout Europe 83 . Human-modified landscapes could be included within the network in a stepping-stone manner 84 , but this would require a case-by-case analysis and consultations with the stakeholders, both of which are beyond the scope of this manuscript.…”

“…providing connectivity) that are outside any type of protection; these areas are composed entirely of natural blocks of land that, in the context of today's anthropogenic intervention, may soon disappear. These IACs could also be vital for amphibians and reptiles for adaptation under anthropogenic climate change, as they would allow populations to track their preferred microclimates 38,78 .…”