EcoScape: Species-specific Functional Habitat Connectivity Via Efficient Parallel Propagation Simulations

Natalia Ocampo-Peñuela, Luca de Alfaro , Jasmine Tai, Natalie Valett, Coen Adler, Artie Nazarov, Montague Neate-Clegg

Well-connected habitats sustain viable populations through gene flow, repopulation potential, and functional habitat extent. Conserving and enhancing habitat connectivity has been identified as a priority to halt extinctions and safeguard 30% of the planet. Conservation prioritization would therefore benefit from habitat connectivity modeling that is applicable at broad spatial and taxonomic scales. We introduce EcoScape, a species-specific computational tool capable of efficiently modeling habitat connectivity across large geographical areas. We describe how it estimates connectivity and flow relative to existing models. To evaluate its outputs, we map connectivity for three avian species across the contiguous United States, and we validate the resulting estimates against community-science occurrence data from eBird.

EcoScape performs hundreds of GPU-parallelized dispersal simulations seeded randomly in habitat, with propagation informed by each species' dispersal ability and habitat preferences. Connectivity is the probability that a habitat pixel can be repopulated from other habitat locations; flow is a pixel's contribution to downstream repopulation, highlighting matrix elements that facilitate connectivity. We demonstrate EcoScape on a synthetic landscape, then map both connectivity and flow layers for Acorn Woodpecker, Pileated Woodpecker, and Steller's Jay from Area of Habitat maps, habitat preferences, and dispersal abilities derived from a global trait dataset. We then use eBird checklists across each species' range to test whether connectivity predicts local occurrence and abundance after controlling for observer effort and habitat patch size.

In the synthetic landscape, we show how EcoScape predicts higher connectivity in larger and better-connected habitat patches, while flow between habitat is higher in a more permeable matrix. For the three focal species, we show that the computed connectivity positively predicts both local abundance and probability of occurrence in habitat grid cells beyond habitat patch size alone. We show that simulations can be efficiently performed in parallel on GPUs, leading to fast computation times that make it feasible to compute connectivity at continental scales.

EcoScape can be applied to any species with sufficient input data, is computationally efficient, and can be validated with readily available data. These advantages enable habitat connectivity mapping at large spatial scales and fine resolutions for hundreds of species, offering guidance for current and future conservation efforts.