Grazing driven architectural plasticity ameliorates soil microenvironments and uncouples plant production from climate variability

1. Understanding how organismal traits adapt to anthropogenic disturbance and topographic heterogeneity is central to predicting ecological processes. Conventional frameworks often overlook the role of plant architectural plasticity and positive interactions in buffering community biomass under environmental stress.2. Here we conducted a four-year manipulative experiment across a topographic gradient in a typical steppe to examine how grazing shapes architectural traits and plant interactions. We focused on three dominant species including Stipa grandis and Artemisia frigida and Potentilla acaulis representing divergent adaptive strategies.3. Results revealed that while the dominant bunchgrass Stipa grandis suffered structural collapse under grazing the rosette forb Potentilla acaulis exhibited compensatory growth via lateral expansion and densification particularly on steep slopes. This morphological shift represented a trait based functional adaptation rather than a mere symptom of habitat degradation.4. Path modeling indicated that the dense and prostrate architecture of Potentilla acaulis actively engineered local soil microenvironments by enhancing fine particle interception and reducing bulk density.5. Consequently, these modified patches functioned as facilitative resource islands driving a shift in plant interaction intensity from competition to facilitation with increasing slope steepness.6. We conclude that grazing driven architectural plasticity promotes specific functional phenotypes essential for niche construction. These traits mediated facilitative patches act as biological buffers that sustain local plant production and uncouple community biomass from regional climate variability in heterogeneous environments.