Ornis Hungarica. vol.2. (1992) p.45-60.
Bird-vegetation relationships along ecological gradients: ordination and plexus analysis
Breeding birds were counted and vegetation structure was recorded along two seres of forest succession, in beech forest (Aconito-Fagetum) and oak forest (Quercetum petraeae-cerris) in Central-Europe. Bird-vegetation relationships were analyzed by two multivariate techniques: canonical correspondence analysis (CCA) and multivariate plexus analysis (MPA). The two methods revealed different aspects of bird-vegetation relationships. CCA demonstrated the dynamical aspect of changes in community structure. In both habitats it revealed two gradients which are important in bird-vegetation relationships. The first axis was interpreted as the successional gradient and the second as the closeness-openness gradient. Results of MPA revealed the association,structure between individual bird species and vegetation components. Multiple regression analysis showed that MPA is sensitive to the detection of both the linear and the non-linear features of bird-vegetation relationships. CCA and MPA gave some new insights into bird-vegetation relationships across the forest succession. They are not alternatives of each other, they revealed different aspects of the relationships.