Bird richness decreases with the abandonment of agriculture in a rural region of SW Europe

Abstract

Land use affects diversity in human-dominated landscape mosaics. Thus, bird species richness may be affected by the balance between agriculture and rural abandonment in long-term human-dominated landscapes. We explored whether land abandonment is related to species richness and abundance of birds in a rural area of SW Europe. We conducted avian point count surveys and landscape characterization using GIS in 234 (3 ha) plots around 39 small, rural villages. These villages traditionally subsist on agricultural practices and currently exhibit different levels of land abandonment across a total of 150,000 ha in Galicia, Spain. We recorded 1548 bird individuals belonging to 56 species. Both bird species richness and abundance were higher in areas where proportionally more surface is dedicated to agriculture than when successional bushlands dominate the area. The effect of abandonment on species richness was buffered by altitude. At sites of higher elevation, abandonment did not have a negative effect on richness. Our results indicate that a conservation approach that favors traditional practices, such as subsistence agriculture, should be taken to avoid land abandonment and help maintain avian diversity linked to human systems. This approach would also conserve traditional human livelihoods.