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.

Questo articolo esplora i giri e le loro implicazioni.

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