LAUSR

Description Land abandonment is critical when assessing global biodiversity and conservation Land abandonment and rural depopulation are accelerating globally. In less than 50 years, the proportion of the human population living in rural areas has decreased by ∼25% (1). Abandonment takes many shapes, and no single definition has been accepted. Most often, land abandonment refers to a termination of agricultural activities for at least 5 years (to differentiate it from fallow land) and is quantified at the crop-field scale (2, 3). Other types of abandonment have received less attention, such as abandoned pastures, forestry areas, mines, factories, and entire human settlements. Here, “land abandonment” broadly captures the end of human activities. Since the 1950s, abandoned land has accumulated to up to 400 million ha globally (3), an area roughly half the size of Australia. Given this scale, there is an urgent need to develop a vision of how to achieve balanced benefits for biodiversity conservation, ecosystem services, and people’s livelihoods on abandoned land.