‘Depopulation’ refers to a process in which the population density of an area decreases steadily over time. Increased human population is certainly a threat to environmental sustainability, but local phenomena of depopulation may be seen also as threats to local environmental sustainability. They will become more and more frequent as the human population (fortunately) reaches its peak towards 2050 at less than 9 billion people.
During industrialisation, cities expand rapidly, concentrating the location first of industry and then services. This expansion draws labour in from rural areas, where at the same time the mechanisation of farm activities encourage further rural-to-urban migration. Rural depopulation processes affect regions where the rural exodus outstrips natural growth, reducing the total number of inhabitants to a critical level and causing an ageing of demographic structures. Nevertheless, depopulation may also be caused by displacement because of large infrastructure investments.
This process of depopulation provokes a range of environmental impacts. It can actually increase negative environmental pressures on biodiverse agricultural production through increased soil erosion and invasions by pests and weeds, leading to reduction of biodiversity. As people leave an area, one dominant habitat comes to take over from the diverse mosaic of human-maintained landscapes. This ‘ecological homogenisation’ can lead to a decrease in biodiversity at a local level. Other ecological impacts include soil degradation resulting from inadequate terrace maintenance in mountainous areas, as is the case across large swathes of Mediterranean and Southeast Europe.
Another phenomenon that may be related to depopulation is increased frequency of forest fires. Rural depopulation also transforms territory, sometimes leading to a loss of valued cultural landscapes. Nevertheless, the rural–urban shift may have positive implications for consumption patterns. Dense urban areas offer relatively more integrated service provision such as waste collection and collective transport.
For further reading:
Jacob, Aerin, L., Vaccaro, Ismael, Hartter, Joel, Chapmans, Colin, A. (2008) Integrating landscapes that have experienced rural depopulation and ecological homogenization into tropical conservation planning. Tropical Conservation Science Vol.1 (4) 307-320,
MacDonald et al. (2000) Agricultural abandonment in mountain areas of Europe: environmental consequences and policy response, J. Environ. Manag. 59, pp. 47–69
This glossary entry is based on a contribution by Leah Temper
EJOLT glossary editors: Hali Healy, Sylvia Lorek and Beatriz Rodríguez-Labajos