Like many temperate floodplain forests in Europe, the Leipzig Floodplain Forest (LFF) has been impacted by anthropogenic disturbances, such as historical forestry practices and hydrological alterations. As a result, the forest's tree composition has changed, as evidenced by the declining abundance of typical floodplain species—like pedunculate oak (Quercus robur)—which play an important role in maintaining biodiversity. Notably, oak is not naturally regenerating in the mature forest, situating a need for management intervention to assist oak regeneration. One such management intervention is to plant oak in femels, i.e. small-scale clearings, or canopy gaps. However, it remains unclear whether small femels (<0.5 ha) can ensure effective oak regeneration. Moreover, city foresters aim at reaching 40 % average oak cover in the forest overstory by planting oaks in femels, but uncertainty remains regarding how much of the area would have to be planted with oaks per year to reach this goal.
To explore these questions, we collected forest inventory data from oak femels ranging from 0.1 to 0.6 ha in size and compared oak density, size, growth, and mortality across femel sizes. Furthermore, we used the demographic Perfect Plasticity Approximation (PPA) model to simulate oak overstory cover over time under a femel management regime to assess the percentage of the forest area that should be planted with oaks per year accounting for different groundwater conditions.
