2025/04/23 by Benjamin Seleb, Louis Gonzalez, Seleb, Benjamin +4 · 1 voice · 1 citation
Biochemistry, Genetics and Molecular Biology · #FOS: Biological sciences #Quantitative Methods (q-bio.QM) #q-bio.QM
paper · pdf · doi:10.48550/arxiv.2504.17496
arxiv published 2025/04/23 · arxiv updated 2026/07/04
Terracettes, striking, step-like landforms that stripe steep, vegetated hillslopes, have puzzled scientists for more than a century. Competing hypotheses invoke either slow mass-wasting or the relentless trampling of grazing animals, yet no mechanistic model has linked hoof-scale behavior to landscape-scale form. Here we bridge that gap with an active-walker model in which ungulates are represented as stochastic foragers moving on an erodible slope. Each agent weighs the energetic cost of climbing against the benefit of fresh forage; every hoof-fall compacts soil and lowers local biomass, subtly reshaping the energy landscape that guides subsequent steps. Over time, these stigmergic feedbacks concentrate traffic along cross-slope paths that coalesce into periodic tread-and-riser bands, morphologically analogous to natural terracettes. Our model illustrates how local foraging rules governing movement and substrate feedback can self-organize into large-scale topographic patterns, highlighting the wider role of decentralized biological processes in sculpting terrestrial landscapes.