The forest understorey, composed of herbs, ferns, grasses and dwarf shrubs, is an important functional component of temperate forest ecosystems, influencing tree regeneration rates, and carbon, water and nutrients cycles. This vegetation layer is, however, often ignored when modelling the impacts of climate change on forests, while past observational and experimental studies have already shown that understoreys are indeed sensitive to climate change. Our mechanistic understanding of this understorey response to climate change is, however, limited and makes it hard to predict future changes, and to adapt forest management practices to mitigate impacts. In this project, we aim for a better understanding of how climate warming impacts the understorey and, more specifically, understorey plant height, one of the crucial traits influencing competitive processes but also the functioning of the understorey. By integrating individual plant responses to warming, inferred from experimental and observational data, in a process-based model to predict understorey community dynamics, we will be able to gain a more mechanistic understanding of understorey responses to climate warming. By simulating a range of alternative management practices under different warming scenarios, the project aims to support the design of forest management practices that can mitigate adverse effects of climate warming in the understorey.