Quantifying the impacts of 166 years of land cover change on lowland bird communities

Land cover change for agriculture is thought to be a major threat to
global biodiversity. However, its ecological impact has rarely been
quantified in the Northern Hemisphere, as broad-scale conversion to
farmland mainly occurred until the 1400s-1700s in the region, limiting the
availability of sufficient data. The Ishikari Lowland in
Hokkaido, Japan offers an excellent opportunity to address this issue, as
hunter–gatherer lifestyles dominated in this region until the mid-19th
century and land cover maps are available for the period of land cover
changes, i.e., 1850-2016. Using these maps and a hierarchical community
model of relationships between breeding bird abundance and land cover
types, we estimated that broad-scale land cover change over a 166 year
period was associated with more than 70% decline in both potential
species-richness and abundance of avian communities. We estimated that the
abundance of wetland and forest species declined by >88%, whereas
that of bare-ground species increased by >50%. Our results suggest
that broad-scale land cover change for agriculture has led to drastic
reductions in wetland and forest species and promoted changes in community
composition in large parts of the Northern Hemisphere. This study provides
potential baseline information that could inform future conservation
policies.