A new study published in the journal Nature Communications shows that grassland and arable land could better provide different services at the same time if the use of pesticides and mineral fertilizers is reduced.
According to the researchers from the German Centre for Integrative Biodiversity Research (iDiv), the Helmholtz Centre for Environmental Research (UFZ), Leipzig University (UL) and Martin Luther University Halle-Wittenberg (MLU), these results also apply under possible future climate conditions.
The study is the first to look at different ecological-economic measures of multifunctionality that take into account the preferences of different interest groups for different ecosystem services. For example, farmers place more value on food production than other interest groups. In addition, society as a whole benefits from regulating ecosystem services, such as carbon sequestration or the preservation of water quality.
There are debates about which type of cultivation is best suited to the various interests of society. Intensive farming uses mineral fertilizers and synthetic pesticides to increase yields. Such aids are avoided in extensive farming. Each type of cultivation has its advantages and disadvantages: Intensive farming can lead to higher yields, but also to environmental pollution; extensive farming, on the other hand, may require more land due to the lower yield.
"The design of our study allowed us to investigate the impact of key elements of global change, such as land-use change and climate change, on the provision of various ecosystem services," says first author Friedrich Scherzinger, an alumnus of iDiv and the UL. "These ecosystem services are essential for human well-being. By combining economic and ecological research approaches, we can get a more holistic picture of the many interconnected elements of an ecosystem."
Integrating ecology and economy from the outset
The scientists used a large field experiment facility with five types of land use under two different climate scenarios (current and possible future climate): the Global Change Experimental Facility (GCEF) operated by the UFZ. In order to assess ecological multifunctionality, 14 ecosystem functions were examined, such as nitrogen fixation or above-ground biomass production. To assess economic multifunctionality, the team determined the total financial value of the six ecosystem services of food production, carbon sequestration, water quality, soil health, biodiversity conservation and landscape aesthetics.
"The Global Change Experimental Facility is a unique experiment," says co-author and GCEF coordinator Dr. Martin Schädler, Ecology at UFZ and iDiv. "This allows us to directly compare how different types of land use react to climate change under standardized conditions - without the disruptive effects of unequal local conditions. This is particularly important when we want to compare intensive and extensive systems, as conditions in the real world often differ considerably."
As the scientists took into account the preferences of farmers, residents, environmentalists and tourism associations from the outset, they were able to evaluate the ecosystem services more comprehensively than with a purely economic approach.
"Higher levels of biodiversity have a stabilizing effect on biomass yields and make them less susceptible to disturbances, similar to a diversified investment portfolio," says Martin Quaas, economist at iDiv and UL and senior author of the study. "Our calculations of the natural insurance value of biodiversity are based on this effect."
The results suggest that future climate change and intensive management will reduce the ecological multifunctionality of grassland and arable land. Overall, the economic benefits of ecosystem services are approximately 1.7 to 1.9 times higher with extensive management than with intensive management, for both grassland and arable land. However, if only farmers’ preferences are taken into account, the multifunctionality of grassland increases due to the use of pesticides and nitrogen fertilizers. The results are based on the comparison per unit area; due to the different productivity of intensive and extensive farming, a comparison per unit yield could be different.
Combining soil biodiversity and ecosystem services
The research team also investigated the relationship between soil biodiversity (the diversity of life in the soil) and ecological multifunctionality under different land use types and under current and possible future climate conditions. The results suggest that soil biodiversity may play an important role in an ecosystem’s ability to fulfill multiple functions simultaneously. Ecosystems with low soil biodiversity could be particularly vulnerable under future climate conditions.
"Around 60 percent of all species live in the soil. These soil organisms are not only incredibly diverse, but they are also the functional backbone of our ecosystems," explains Nico Eisenhauer, soil ecologist at iDiv and UL and senior author of the study. "The results of our study show that we can preserve soil biodiversity with targeted management strategies, and thus also the various services that nature provides for us."
The study is an important step towards a holistic and comprehensive approach. The authors emphasize that the social benefits of agriculture could decrease significantly due to climate change, the loss of biodiversity and excessive amounts of agrochemicals.
"Our study shows that farmers with intensive cultivation achieve the maximum yields, but the provision of ecosystem services is highest with extensive cultivation," says Scherzinger. "Traditionally, it is the farmers who cultivate the land. The social benefit can therefore only be optimal if a system is created that offers farmers incentives and compensates for the difference between the income from intensive and extensive farming."
However, the study does not take all relevant aspects into account, such as landscape diversity or the area required per yield unit. This makes it difficult to draw comprehensive conclusions regarding the optimal management type.
"Future research should focus on the provision of ecosystem services at the landscape level and the role of landscape heterogeneity for an optimal societal outcome," concludes Scherzinger.
Original publication
(Scientists with iDiv affiliation and alumni in bold)
Scherzinger, F., Schädler, M., Reitz, T., Yin, R., Auge, H., Merbach, I., Roscher, C., Harpole, S., Marder, F., Blagodatskaya, E., Siebert, J., Ciobanu, M., Eisenhauer, N., Quaas, M. (2024). Sustainable land management enhances ecological and economic multifunctionality under ambient and future climate, Nature Communications, DOI: 10.1038/s41467’024 -48830-z
