Forest restoration has become a primary task, not only to cope with an increasing demand on forest products, but also to fi ghtclimate change and compensate for an accelerated global deforestation. However, many of the current practices used in forestrynurseries to produce forest planting stock have adverse effects on the environment. The main objective of the ZEPHYR project,funded by the European Commission under the Seventh Framework Programme (FP7), is to develop an innovative zero-impacttechnology for the pre-cultivation of forest regeneration materials that is not affected by the outdoor climate. Among the maincomponents to be improved are artifi cial lighting sources used for cultivation. Traditional fl uorescence lamps are to be replacedby LED grow lights with spectra tailored to the seedlings’ needs. The present work investigates biological responses of Piceaabies and Pinus sylvestris to six different light spectra. The pre-cultivation has been done following standard growth protocolsduring 5 weeks with a photoperiod of 16 h at 100 μmol/m2/s. This has been done under controlled closed conditions with a roomtemperature of 20 °C and a relative humidity of 60%. The analyses have shown clear differences among the treatments and theiradapting capacity when transplanted.