Fig. 1. Bird population change and habitat gradients Univariate relationships
between population change of 34 farmland bird species in the Czech Republic
estimated from 1985–1989 to 2001–2003 and positions of particular species along
two habitat gradients: (a) from open habitat to shrub and trees, (b) from arable land
to grassland. Species’ positions along the gradients were calculated by canonical
correspondence analysis (see Section 2.3 for more details). Population changes
were expressed at a common scale for all species from
2 to 2 (see Section 2.2 for
more details). Note that the relationships are not adjusted for the effects of other
predictors.