Local and Landscape Scale Effects of Heterogeneity in Shaping Bird Communities and Population Dynamics
Résumé
Farmland landscapes support very high
biodiversity (Pimentel et al., 1992), including
functional species that provide ecosystem services
(Tscharntke et al., 2005) and flagship species
for wider ecosystems. However, over the
past 50 years, biodiversity has strongly declined
in agricultural areas, with major losses in plants,
amphibians, reptiles, arthropods, mammals,
and birds, and these losses have been attributed
to agricultural intensification (Robinson and
Sutherland, 2002; Inger et al., 2015). Agriculture
intensification refers to the combination of rapid
land use changes with, e.g., the replacement of
natural habitats by crops, and more intensive
use of existing farmland (Krebs et al., 1999;
Robinson and Sutherland, 2002; Stoate et al.,
2001). About 50% of all European bird species
live in rural landscapes (Tucker, 1997), but
farmland birds have declined in Europe much
faster (57% on the European Union farmland
bird indicator between 1980 and 2013, EBCC,
2017) than in other ecosystems, i.e., birds were
more or less stable in forests during the same
period (EBCC, 2017). Farmland bird specialist
species, even extremely common species such
as the skylark Alauda arvensis, have declined
by more than 50% in the past 30 years (Gregory
et al., 2005, Vorísek et al., 2010). Although the
main service expected in farmland is obviously
food production, species and habitat conservation
in agroecosystems are important issues,
since farmland species provide other ecosystem services and are often the elements of biodiversity
that are most accessible to humans close
to urban areas (Power, 2010). Biodiversity
loss has therefore additional consequences for
ecosystem function and, ultimately, societal
repercussions.