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We investigated how richness and composition of vascular plant species in the understory of a mixed hardwood forest stand varied with respect to the abundance and composition of the overstory. The stand is in central Spain and represents the southernmost range of distribution of several tree and herbaceous species in Europe. Understory species were identified in 46 quadrats (0.25 m 2 ) where variables litter depth and light availability were measured. In addition, we estimated tree density, basal area, and percent basal area by tree species within 6-mradius areas around each plot. Species richness and composition were studied using path analysis and scaledependent geostatistical methods, respectively. We found that the relative abundance of certain trees species in the overstory was more important than total overstory abundance in explaining understory species richness. Richness decreased as soil litter depth increased, and soil litter increased as the relative proportion of Fagus sylvatica in the overstory increased, which accounted for a negative, indirect effect of Fagus sylvatica on richness. Regarding understory species composition, we found that some species distributed preferentially below certain tree species. For example, Melica uniflora was most frequent below Fagus sylvatica and Quercus petraea while the increasing proportion of Q. pyrenaica in the overstory favored the presence of Cruciata glabra, Arenaria montana, Prunus avium, Conopodium bourgaei, Holcus mollis, Stellaria media and Galium aparine in the understory. Overall, these results emphasize the importance of individual tree species in controlling the assemblage and richness of understory species in mixed stands. We conclude that soil litter accumulation is one way through which overstory composition shapes the understory community.

& Key message Small-scale forest interventions (< 0.75 ha) promoted advanced regeneration and woody plant betadiversity without increasing ungulate habitat use and detrimental browsing damage. Rubbing damage by ungulates was higher in the treated areas and no effect was found on woody plant alpha-diversity. & Context Adapted silviculture is needed to promote forest persistence and plant diversity in the current context of wild ungulate overabundance. & Aims This study examines the ungulate effects on tree recruitment and woody plant diversity after silviculture treatments (small-scale regeneration fellings on Pinus species). & Methods We compared tree recruitment, browsing/rubbing damage, and woody plant diversity on 17 pairs of control/treated areas in an ungulate-dominated Pinus halepensis forest. & Results Recruitment levels were significantly higher in the treated areas as compared to intact (control) plots only for large saplings and juveniles (> 130-cm high). Ungulates did not use the treated areas more often than the control plots but caused significantly greater rubbing damage in the treated areas. Silvicultural treatments did not have a significant effect on alpha woody plant diversity but did promote beta-diversity, with a 49.7% woody species turnover. We did not find any clear patterns indicating that the treated areas suffered heavier browsing damage across all woody plant species. & Conclusion This study highlights that small-scale forest interventions (< 0.75 ha) are small enough to avoid greater habitat use and browsing damage by ungulates but sufficiently large to promote advanced regeneration (large saplings and juveniles), with the additional benefit of increasing woody plant heterogeneity and structural diversity.