Plant diversity struggles in wake of agricultural abandonment
A century later, plant diversity is still struggling in wake of agricultural abandonment. (Picture: Forest Isbell)
Andropogon gerardii, a tall grass native to the grassland regions in North America. (Picture: Adam Clark)
Although local plant diversity increases over time, plant productivity does not significantly recover from agricultural use.
Based on a media release of the University of Minnesota.
Minnesota/Leipzig. Decades after farmland was abandoned, plant diversity and productivity struggle to recover. This has been shown by a new research, published in the journal Nature Ecology & Evolution. Researchers from the German Centre for Integrative Biodiversity Research (iDiv), the Helmholtz Centre for Environmental Research (UFZ) and the University of Minnesota examined plant diversity and plant productivity on fields that had been ploughed and abandoned for agricultural use. Although local grassland plant diversity increased over time, plant productivity did not significantly recover.
The international team of researchers examined 37 years of data tied to plant diversity (species richness, i.e., number of species) and plant productivity (i.e., biomass or amount of plants) related to 21 grasslands and savannas in Minnesota. Most of these fields had been ploughed and abandoned for agricultural use between one and 91 years prior. The researchers then compared the plots to nearby land that has not been significantly impacted by human activity.
They found that one year after abandonment, the fields had, on average, 38% of the plant diversity and 34% of the plant productivity for the land that was never ploughed. 91 years after abandonment, the fields had 73% of the plant diversity and 53% of the plant productivity. This shows that local grassland plant diversity increased significantly over time, but incompletely recovered. Plant productivity did not significantly recover.
The researchers suggest that the slow and incomplete recovery of species on abandoned farmland in Minnesota is likely happening in ecosystems around the world where land has been cleared for agriculture, logging or other human activities.
“The amount of land being used for agricultural purposes has slowly been decreasing, leaving some 11 million square miles of old fields and recovering forests across our planet,” said co-author Dr Adam Clark, who is currently a postdoctoral researcher with the Helmholtz Centre for Environmental Research (UFZ) and the German Centre for Integrative Biodiversity Research (iDiv). “In these spaces, active restoration efforts may often be needed to restore biodiversity and prevent the extinction of species.”
Restoration tactics can include using prescribed burns, dispersing seeds, using haying to remove nutrients added through fertilization and reintroducing others in the food chain (e.g., herbivores, predators) pushed out of the area.
“When taken at a global scale, fossil records indicate plant species are going extinct at rates hundreds of times faster than the natural extinction rate,” said first author Prof Forest Isbell, assistant professor in the College of Biological Sciences (CBS). “At this localized level, we’re seeing how human activity can impact the loss of species.”
Original publication:
(iDiv scientists bold)
Forest Isbell, David Tilman, Peter Reich, and Adam T. Clark. "Deficits of biodiversity and productivity linger a century after agricultural abandonment". Nature Ecology and Evolution 3:1533–1538, 2019. DOI: 10.1038/s41559-019-1012-1
Contact:
Dr Adam Clark
Physiological Diversity
German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig
Helmholtz Centre for Environmental Research (UFZ)
Email: adam_thomas.clark@idiv.de
Web: www.idiv.de/en/groups_and_people/employees/details/798.html
Kati Kietzmann
Media and Communications
German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig
Phone: +49 341 9733106
Email: kati.kietzmann@idiv.de
