The potential positive effects of herbivores on plants have been the subject of debates for decades. Whiletraditionally, herbivory was considered to have a negative impact on plants, some studies also reportedpossible mutualism between plants and herbivores. Plant defences, and in particular tolerance and resis-tance, seem to play an important role in shaping plant-herbivore interactions. The aim of this study isto show how a direct plant compensation mechanism translates into apparent compensation, i.e. thelong-term biomass response to herbivory, in simple plant-herbivore models. A special emphasis is thenput on how it interacts with resistance mechanisms. A qualitative study of the proposed models showsthat they can exhibit different plant-herbivore patterns, including neutral, antagonistic (negative appar-ent compensation) and mutualistic (positive apparent compensation) interactions. Moreover, it is shownthat density dependence plays a crucial role since, for a given system, the realized plant-herbivore pat-tern critically depends on the initial plant and herbivore levels. Our study shows the importance of directcompensation for the presence of plant-herbivore mutualism, a finding which we show, has significantimplications both in ecosystems ecology and in agricultural pest management.