Percolation
The mathematics of connectivity thresholds, where a system suddenly becomes traversable end to end.
Why it matters now
Below a critical density nothing crosses; just above it, everything does. Fire crosses a landscape, disease crosses a herd, water crosses a soil, an idea crosses a society. Habitat fragmentation has a percolation threshold, and knowing where it sits tells a planner exactly how much corridor is enough.
Where this is happening on Earth
- North AmericaHabitat fragmentation thresholds in North American forestsConnectivity collapses abruptly below roughly sixty percent remaining habitat in many model landscapes.
- South AmericaAmazon forest fragmentation and fire percolationCleared edges let fire cross forest that would otherwise not burn.
- EuropeGroundwater flow through fractured karst, Balkans and AlpsContaminant transport governed by whether fracture networks connect.
- AsiaPeat fire spread through drained Indonesian landscapesOnce moisture falls below a threshold, fire percolates underground across enormous areas.
- AfricaRangeland connectivity for wildlife across fenced southern AfricaFence density determines whether large mammal movement remains possible at all.
The idea itself
The encyclopedia entry first, then live searches at journals and magazines that keep returning current work on this specific idea.
Current reporting from around the world
Standing feeds at reputable periodicals. These stay fresh on their own, which is why they are here instead of a list of articles that would be out of date within a season.