Abandoning land transforms nature

View from an abandoned house into the overgrown landscape Photo: Malkolm Boothro
View from an abandoned house into the overgrown landscape Photo: Malkolm Boothroyd
Research team including Göttingen University shows impact on biodiversity of abandoned land

The past 50 years have seen an increased exodus of populations from rural to urban areas and more than half the world’s population now lives in or around a city. This proportion is likely to rise to around 70% by 2050, leading to a rise in the number of abandoned fields, pastures, mines, factories, and even entire villages. Since the 1950s, the amount of abandoned land has grown to around 400 million hectares globally, yet the impact of this changing situation - exacerbated by war and climate change - on nature is not yet entirely clear. Researchers from the University of Göttingen and the International Institute for Applied Systems Analysis (IIASA) in Austria show that abandoning lands could be both an opportunity and a threat for biodiversity. Their review highlights why abandoned lands are critical in the assessment of global restoration and conservation targets. The findings were published in a perspective piece in Science.

Professor Johannes Kamp of the University of Göttingen’s Department of Conservation Biology and his colleague Dr Gergana Daskalova from IIASA took a closer look at abandoned land to explore how biodiversity is influenced, and what this means for ecology and conservation. They observe that the effect on biodiversity can be positive or negative. The biggest wins are likely to be achieved in abandoned areas that were previously intensively farmed and where biodiversity was low. Abandonment allows the return of plant life, birds and insects that can survive in recently disturbed ecosystems. Abandonment causes a reduction in the human activity and can lead to the -rewilding- of landscapes - which allows large herbivores and carnivores to return to areas where they had disappeared earlier. However, not all abandoned land will recover without help, and some intensively farmed land will never return to what it once was. In addition, any gains in biodiversity on abandoned land can be undone, even within a decade, when land is recultivated or repurposed, especially if used for industry, including large-scale bioenergy, wind or solar energy production.

In contrast, areas that have traditionally been used for low-intensity, or subsistence farming over a long period of time, demonstrate how the close ties between the people and the land create interdependent ecosystems that break down after people move away. Here, abandonment can lead to the loss of local rare species or the proliferation of only one or two dominant species at the expense of others.

-The factors that drive depopulation and land abandonment are intensifying due to issues like climate change and the rapidly changing social and geopolitical landscape. The Russian invasion of Ukraine, for example, has already created new abandoned areas,- says Daskalova. -The scale and speed of this global change highlights the importance of this issue.-

-Despite the urgency, the consequences of land abandonment are not completely understood,- says Kamp. -There has been little attention paid to the interactions between abandonment, loss of culture and tradition, and ecological change. But understanding these interactions could bring real opportunities to design future landscapes that improve both quality of life for people and biodiversity conservation.-

Original publication: Daskalova, G.N., & Kamp, J. (2023). Abandoning land transforms biodiversity. Science adf1099