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P. González-Moreno et al. 2010. The influence of spatial structure on natural regeneration and biodiversity
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larger plot: a 5-m radius circle to measure the number of saplings (DBH = 2.5-7.5 cm) and
seedlings (DBH < 2.5 and height < 1.3 m) of tree species, and a 10-m radius plot to measure the
species composition and abundance by the Braun-Blanquet cover-abundance scale.
Regeneration within pine plantations was measured as seedling abundance. The species
considered in the analysis was Quercus ilex subsp. ballota (Desf.) Samp. (Q. ilex). Other major
species were not considered due to their low abundance in the inventory. Saplings were not
considered, since oak saplings could have been established before the establishment of the pine
plantation, and pine “saplings” could be suppressed old planted individuals. Plant diversity was
measured using the Shannon diversity index for the total of species and considering only
herbaceous species, only flesh-fruited woody species or only dry-fruited woody species. The
distinction among woody species was considered in order to account the differences in dispersal
syndrome. Flesh-fruited woody species usually have endozoochorous syndromes whilst rest of
species can have other syndromes such as exozoochorous or anemochorous. This distinction
was not made for herbaceous species because most of them (> 95 %) have dry fruits and abiotic
dispersal.
A simplification of the forest vegetation map of Andalusia 1:10 000 (CMA 2001) was used to
identify pine plantation areas and calculate patch geometry and vegetation context variables.
The different vegetation classes used were selected according to their possible contribution to
regeneration and plant diversity in pine plantations. The vegetation classes considered were: (1)
pine plantation (> 50 % tree cover and > 75% conifers), (2) Oak and broadleaved species (> 5 %
tree cover and oak presence), (3) shrublands (< 5 % tree cover, > 20 % shrub cover and