Structural characterization and analysis of the regeneration of woodlands dominated by Juniperus oxycedrus L. in west-central Spain
Jovellar Lacambra, L. C. | Fernández-de-Uña, L. | Mezquita Santos, M. | de Lerma, F. B. L. | Escudero San Emeterio, V.
This work addresses the structural characterization of Juniperus oxycedrus-dominated woodlands in west-central Spain, as well as the analysis of the regeneration of this species in the presence of other species (mainly Quercus ilex) as a function of different environmental and land-use factors. The two densest populations of the species were sampled and different physiographic and land-use parameters were obtained. First, a structural characterization, specifically focused on regeneration, was carried out, based on the count of individuals and their classification according to their size (seedlings, saplings, or adults) and position (either beyond or below the canopy). The use of Generalized Linear Models (GLM) and Regression Trees permitted the identification and analysis of environmental and land-use variables significantly related to regeneration. Juniper woodlands in this part of Spain generally show a remarkable level of regeneration, although some significant differences were detected between the two existing populations. Of the factors studied, time since regeneration started, elevation, and soil rock surface cover influence J. oxycedrus regeneration at most of the individual classes considered, indicating the significance of these variables in this species regeneration. Canopy cover and depth of the organic layer and zone also affect several of the recruitment classes. Furthermore, radiation, the time elapsed since regeneration started, elevation, and aspect affect stand structure to a significant extent. The results of this study enlarge the knowledge on J. oxycedrus regeneration and woodland structure, providing helpful information for the conservation of these protected habitats. © 2012 Springer Science+Business Media Dordrecht.
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