Pinus nigra Arn. ssp salzmannii seedling recruitment is affected by stand basal area, shrub facilitation and climate interactions
Le recrutement de semis de Pinus nigra Arn. ssp salzmannii est fonction de la surface terrière, de la facilitation par les buissons et de l'interaction avec le climat
Résumé
Spanish Black pine forests in the Cuenca Mountains (Spain) have traditionally been managed using the shelterwood method. However the lack of natural regeneration has been one of the most important problems since the end of the 19th century, sometimes jeopardizing stand persistence. On this context, nurse shrubs and an adequate overstorey density may have facilitative effects by increasing seed emergence and seedling survival in harsh environments. The main objective of this work was to evaluate the influence of stand basal area (15-20; 25-30 seedling recruitment of Spanish black pine. The study showed that the success of Spanish black pine recruitment results from complex interactions between stand basal area and shrub protection, indeed modulated by the climatic conditions of the given year. Shrub facilitation is only obvious the drier years under moderate light, whereas seedling survival is favoured by higher light availability the wet years.