Abstract
Aim of study: This study aimed to determine the influence of topography and stand-structure on the characteristics of shrub communities and tree regeneration in a Mediterranean forest.Area of study: The Navahondona forest in Cazorla mountain range (SE Spain).Material and Methods: Data from 298 inventory plots were analysed by means of Generalized Linear Models (GLM) to test the effects of aspect, altitude and stand basal area on shrub cover and diversity. Likewise, the effects of these three factors plus shrub cover on the recruitment of Spanish black pine (Pinus nigra spp. salzmannii) and two oak species (Quercus ilex and Q. faginea) were analysed by GLMs. Additionally, the influence of topography and forest structure on the specific distribution of shrub species was analysed with multivariate methods.Main results: Shrub cover and diversity were generally low and did not change across the topographic gradient. Tree density was the only study variable affecting (negatively) shrub cover. However, shrub composition changed with aspect and altitude. Both pine and oak regeneration benefited from partial tree cover at intermediate values of stand density, but only oak regeneration was facilitated by shrubs.Research highlights: Altitude, aspect and stand basal area influence the characteristics of shrub communities and tree regeneration. Proactive management of dense pinewoods might be needed to increase shrub and tree diversity.Key words Pinus nigra; Quercus sp.; altitude; aspect; facilitation; Shannon diversity index.
Highlights
Species composition and species interactions are two of the three attributes that describe forest biodiversity, the third being structure (Franklin, 1988)
Material and Methods: Data from 298 inventory plots were analysed by means of Generalized Linear Models (GLM) to test the effects of aspect, altitude and stand basal area on shrub cover and diversity
The Correspondence Analysis (CCA) (Figure 2) revealed that the presence of Lavandula latifolia is associated with North-facing slopes and that Echiospartum boissieri, Berberis vulgaris and Erinacea anthyllis are species from sites located at higher altitude, whereas Rosmarinus officinalis and Cistus sp. are mostly found on South-facing slopes and lower altitude
Summary
Species composition and species interactions (functioning) are two of the three attributes that describe forest biodiversity, the third being structure (Franklin, 1988). Mediterranean mountains attain very high scores of diversity in vascular plants (Médail & Quézel, 1999) In these areas, understory vegetation typically represents a major component of plant diversity (Blanco et al, 1998), and, not surprisingly, it plays an important role in forest ecosystem functioning. It has been shown that tree seedlings generally tend to become established in the vicinity of shrubs in Mediterranean environments, because shrub shade ameliorates the risk of suffering photo-inhibition and/or desiccation (Castro et al, 2004; Gómez-Aparicio et al, 2004; Mendoza et al, 2009a) This represents a plant-plant interaction of facilitation, which net outcome depends on the intensity of abiotic stress and on the phylogeny of the interacting plants (Tíscar & Linares, 2013). Gómez-Aparicio et al (2004) showed that the strength of facilitation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
