Role of tussock morphology in providing protection from grazing for neighbouring palatable plants in a semi-arid Mongolian rangeland

Background: Palatable plants in rangelands may be protected from herbivore grazing by the presence of less palatable neighbouring plants. The protective role of benefactor species on palatable species often collapses under heavy grazing, but the underlying mechanism—the relationship between the reduced protective role and grazing damage to benefactor species—remains unclear.Aims: To clarify whether the protection of surrounding palatable species conferred by a less palatable tussock grass (Achnatherum splendens) is reduced under heavy grazing, focusing on the changes to tussock morphology caused by grazing.Methods: In the Mongolian steppe, we measured the morphological traits of A. splendens tussocks, plant density of palatable graminoids and grazing damage in three A. splendens microhabitats (inside, adjacent to, and outside tussocks) under light and heavy grazing areas.Results: A. splendens tussocks had smaller basal area and culm height, and greater culm density under heavy grazing. The densities of pa...