The large-scale conversions of forest to agricultural land and subsequent afforestation represent a major disturbance across western European and eastern North-American landscapes during the past centuries. In certain landscapes up to 80% of the present forest area is recovering from former agricultural land use. Following the afforestion of agricultural land herb species need to establish again through recolonisation. However, it is thoroughly documented that forest herbs have low abilities to recolonise post-agricultural forest (20-100m per century). Forest herb diversity and the value for nature conservation of these recent forests is therefore much lower compared to ancient forest, i.e. forest that has never been cleared for agriculture at least since the oldest land use maps. There is an overwhelming amount of evidence that the low dispersal capacity of many forest herbs in space and time (seedbanks) partly accounts for this slow recovery. In addition, it is more than likely that persistently altered habitat conditions including higher nutrient availability further hampers forest herb layer recovery. The general aim of this project is to evaluate which forest herb communities are able to develop in recent forests established on phosphorous enriched soils (former agricultural land). Specific aims of this project are: (1) To determine if phosphorus and light availability actually have an effect on the production of biomass and the composition of a forest plant community. (2) To compare plasticity in allocation and performance between contrasting forest herbs with respect to phosporus availability and light. The relation with colonisation capacity is also checked. (3) To evaluate whether allocation and performance of forest herbs changes during forest development on former agricultural land as bioavailability of phosphorus changes.