Enabling an acceptable and equitable quality of life for all while avoiding dangerous climate change and maintaining a functional biosphere is the existential challenge of our time. A critical problem in the global transformation towards planetary stewardship is the intensifying competition for land. Satisfying the growing human population’s need for housing, food, and energy is shrinking, fragmenting, and degrading natural ecosystems, making human land use the biggest driver of biodiversity declines in terrestrial environments. While well-managed urbanisation may help to minimise environmental degradation, inadequately managed urban land conversions are expected to be an increasingly prominent driver of habitat and biodiversity loss. In addition, while urgently needed to mitigate climate change, transitioning from fossil fuels to renewable energies may further aggravate land competition and undermine biodiversity conservation directly. Impacts of renewable energy developments can directly contribute to habitat conversion and fragmentation, affect the movement of wildlife, and increase land use intensity. Yet, despite these potentially strong adverse effects on biodiversity, conservation strategies and renewable energy expansion are almost always planned in isolation, reducing the effectiveness and momentum of both efforts. While protected areas have been a fundamental pillar of nature conservation, there is a growing realisation that simply ‘setting aside’ isolated areas of intact nature will not suffice given the growing demand for land. Instead, maintaining and restoring ecological permeability is increasingly recognised as critical to mitigate biodiversity loss and enhance ecological resilience in the face of increasing land competition and climate change. However, securing ecological permeability requires an in-depth understanding of when landscapes become impermeable as a consequence of habitat loss, fragmentation, and degradation. A systematic and generalised assessment of permeability at the global scale and across different taxa is missing.
We aim at developing a global in-depth understanding of landscape transitions from permeable to impermeable. To systematically identify state transitions where landscapes lose or regain their permeability, we propose to introduce the concept of Landscape Criticality, which generalises previous percolation-based approaches to capture the spatial configuration of landscapes. CriticaL aims to answer the following questions: (1) How do different regions across the globe vary in their landscape criticality for anthropogenic objects and land use types? (2) What are critical thresholds when landscapes become impermeable to animal movement and the flow of ecological processes? Are these transitions reflected by landscape criticality thresholds? (3) Can we predict these thresholds and, consequently, prevent the loss of ecological permeability? (4) How will the transition to renewable energies impact landscape criticality, and, consequently, ecological permeability? (5) How can we incorporate these findings into land use planning and conservation?
PIK will contribute in an advising role to landscape criticality & poles of inaccessibility (WP1) and in particular investigate methodology/theory (T1.3). Moreover, PIK will research landscape criticality under future scenarios (WP3) with a focus on specific requirements in Germany.
