In ecological research and agricultural policy, plots are typically classified into categories such as "conventional", "organic/extensive" or "semi-natural". For organic use there is even a certificate (SKAL), but for the other categories there are no certificates or guidelines. In a new study based on eighteen grasslands (in the Ooijpolder near Nijmegen), scientists examined how well the pre-assigned management categories corresponded to what the management data actually showed.
Researcher Rosa Boone: 'We saw that the categories we had assigned in advance did not fully overlap with what the management data showed. Some plots that had been labelled "extensive" were, in the data, much closer to "semi-natural". This is because farmers make their decisions based on local conditions, economic pressures and personal considerations. Two farmers in the same management category may do very different things in practice, which has consequences for soil biodiversity and ecosystem processes.'
Continuous scale
In their study, the researchers present a new, data-driven method that allows for an objective assessment of how land-use intensity can best be described. This method uses a continuous scale, or gradient, that aligns with satellite measurements via Sentinel-2 as independent validation. This indicates that the model approximates reality more closely than the original categories of the grasslands studied.
Implications for farmers, policy and monitoring
'If we use categories that do not accurately describe reality, we may draw the wrong conclusions about the state of nature and soil. Our new approach offers a transparent, data-driven way to describe land-use intensity,' Rosa Boone explains. 'This is relevant not only for future research, but also for improving monitoring programmes and policy for the agricultural landscape. Moreover, a gradient gives more room to farmers who are not yet able to switch to a different category, but who do, for example, manage their land more extensively or more naturally than what is currently regarded as conventional.'