In forest openings, increases in resources like light and nitrogen stimulate the growth of competing shade-intolerant forbs. Consequently, a higher occurrence of tree seedlings below the canopy of adult trees could be observed. These patterns may be explained by indirect facilitation. Here, we test the indirect facilitation model in mountain forest openings and explore the relationship that may exist between species response to indirect interactions and spatio-temporal sticking at the level of forest landscape. Three coniferous species (Abies alba, Picea abies and Larix decidua) and two deciduous broad-leaved angiosperms (Fagus sylvatica and Acer pseudoplatanus) were planted in four forest openings invaded by a tall forb, Epilobium angustifolium. Seedlings were grown for three growing seasons, with and without competing forbs, and with and without a 50% shade cloth that simulated the canopy of the surrounding forests. The initial result showed that the survivorship of larch with neighbors, under or not under artificial shade, was very low. Moreover, the direct effects of shade were negative for all species, but the conifers were much more negatively affected by shade than the angiosperms. Shade strongly reduced aboveground biomass of competing forbs, which improved the availability of nitrogen for the tree seedlings. For deciduous species, our shade treatment induced an indirect positive effect on the survival of these species, likely through the indirect increase in nitrogen availability. This effect was greater than the direct negative effect of shade, so the net effect of shade was positive and there was an indirect facilitation. However, because the indirect positive effect of competition release was outweighed by the direct negative effect of light reduction, the net effect was negative for coniferous species. We conclude that species traits may determine how a species responds to indirect interactions, but that further studies are needed to explore the real potential of indirect facilitation to determine patterns of tree seedling distribution.