Ixodes ricinus (L.), known as the sheep tick, is a tick of considerable significance as a vector of both livestock and human diseases. In Europe, I. ricinus is the principal vector of Lyme disease. This is a potentially serious illness caused by the bacterium Borrelia burgdorferi, which is transmitted to humans during the blood meal of Ixodes ticks. Because risk of human exposure to the disease increases with increasing abundance of the vectors, it is important to better understand the biotic and abiotic factors regulating tick abundance. This insight is especially relevant in the Kempen (Flanders, Belgium) where forest conversion will take place over the next decennia. This research attempts to advance our understanding of the impact of forest conversion on tick abundance through influence of microclimate and food supply for small-sized mammals such as mice and voles, which serve as the main hosts for the immature ticks. Relationships between vertical forest structure, food supply and tick abundance will be examined experimentally. Ticks will be collected by flag sampling of the vegetation and abundance of small mammals will be determined using capture-recapture techniques. The knowledge gained in this study will enable us to determine the risk periods and zones for humans, and will help us to evaluate the implications of forest conversion on public health.