Guirado M., Pino J., Rodà F., Basnou C. (2008) Quercus and Pinus cover are determined by landscape structure and dynamics in peri-urban Mediterranean forest patches. Plant Ecology. 194: 109-119.EnllaçDoi: 10.1007/s11258-007-9278-9
Successional dynamics in Mediterranean forests have been modulated by anthropogenic disturbances during thousands of years, especially in areas densely populated since ancient times. Our objective is to determine whether pine tree cover (early-successional species) and oak tree cover (late-successional species), used as a surrogate of successional stage of peri-urban fragmented forests in the Vallès lowlands (Catalonia, NE, Spain), are primarily determined by (1) climate and topography; (2) anthropogenic disturbances; (3) patch structure; or (4) patch dynamics from 1956 to 1993. Quercus spp. and Pinus spp. tree cover were separately recorded on 252 randomly selected plots of 100 m2, within forest patches ranging in size from 0.25 to 218 ha. Multiple linear regressions indicated that forest patch history is the most important variable determining oak and pine tree cover: new forest patches showed higher pine and lower oak tree cover than recently split patches (i.e. those that became fragmented from large forest areas after 1956). Patches already existing as such in 1956 (pre-existent patches) showed higher pine cover than recently split patches. Oak cover increased and pine cover decreased with increasing forest connectivity of the patch. Finally, highly frequented forests were related to high cover of pines. Climatic and topographic variables were not significant. We conclude that pine and oak cover in these peri-urban forests are mainly determined by recent patch dynamics, but also by the spatial pattern of patches. However, human-induced disturbance can modulate this as there is some evidence for pine being associated with a high human frequentation. © 2007 Springer Science+Business Media, Inc.
Santos K.C., Pino J., Rodà F., Guirado M., Ribas J. (2008) Beyond the reserves: The role of non-protected rural areas for avifauna conservation in the area of Barcelona (NE of Spain). Landscape and Urban Planning. 84: 140-151.EnllaçDoi: 10.1016/j.landurbplan.2007.07.004
This paper explores the association of a set of land variables with bird species richness in the area of Barcelona, subgrouped into nesting and wintering, and three classes of conservation concern: total species, species of European Concern (SPEC 2 and 3), and species included in the Birds Directive. It also analyzes the association of the species richness among these groups, and compares their values inside and outside of the protected areas. Bird data were obtained by field sampling within 1700 l km × l km UTM grid cells, which were sampled between 1990 and 1998 until the entire study area had been assessed. For each cell, derivatives of the following variables were calculated: climate, relief, landscape, geographic position, and human settlement. Relative forest and cropland covers and landscape diversity were the main positive correlates of total species richness, while the average elevation was the prime negative correlate for wintering species. SPEC and Birds Directive species richness were negatively related to forest and urban covers, and positively related to that of croplands and shrublands-grasslands. The species richness of birds of no conservation concern (non-listed) was generally positively related to those of SPEC and Birds Directive species, regardless of whether they were wintering or nesting. There was significantly more bird richness outside the reserves in all but one of the classes of conservation concern-nesting Birds Directive. The study confirms the importance of open habitats and heterogeneous rural landscapes for bird species richness in the study area, and provides conservation guidelines based on regional policy. © 2007 Elsevier B.V. All rights reserved.
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