Working hard or hardly working? Modelling success of current grassland agri-environment schemes

Shortlisted for the Georgina Mace Prize 2023

In this blog post, author Bede West describe his team’s study analysing the potential for agri-environment schemes to achieve positive changes in plant biodiversity.

Plants and soils are the trophic foundations of most temperate terrestrial ecosystems but they are being progressively impacted by climate change, biodiversity loss and a plethora of other environmental impacts. These issues must be tackled across scales, from plot to farm, to region to country and beyond, in order to preserve and enhance the benefits ecosystems provide us.

Agri-environment schemes (AES) are a key policy tool to help achieve this as governments pay land managers to implement specific management interventions that are designed to better restore and maintain biodiversity on their land.

Despite their initial promise, doubt has been recently cast on how effective these schemes and whether they are cost-effective to help address climate change and the biodiversity crisis.

Methodological approach

In an attempt to answer this, our research modelled the potential for AES-prescribed management practices to achieve positive changes in plant diversity in grasslands across Wales, UK, by applying scenarios of change in soil conditions and climate change.

We first constructed a modelling workflow using a baseline 2016 dataset, local plant records, data from literature reviews to construct soil change models, predicted climate variables and an established plant taxa ensemble ecological niche model.

Using this workflow construct, we then modelled the response of plants and soils to the predicted effects of AES over a 13-year time interval, applying change scenarios to represent three different AES management options. We also applied two climate scenarios to determine the extent to which it may modify the impact of AES interventions on plant species compositional turnover.

Modelling workflow. Numbered boxes refer to sections in the research articles methodology. Green boxes represent a coded process (GLMM = Generalised linear mixed effect models); grey boxes represent model runs; white boxes are datasets; white boxes with dashed outlines represent input data

The results suggested that neither the AES-prescribed management or climate change effects would have much impact on grasslands in the next few years. Given that AES prescription agreements are typically arranged for 5 years, this is not long enough to elicit any major changes and the scheme therefore may be considered a not very successful.

However, the modelled scenarios did indicate that in a decade or longer, AES practices would promote conditions suitable for desirable plant assemblages more typical of lower fertility habitats.

Climate change impacts over the modelled time period (2016-2029) were also shown to be much lower than the effects of the prescribed management, though this was a reflection of the relatively short time interval used for climate.

Based on our findings, we suggest that governments should be funding longer and better targeted management options for grassland AES to be successful. This is consistent with other research that suggested management must carry on for longer to see change and interventions should be more impactful per unit of time under agreement.

Read the full article: “Model-based assessment of the impact of agri-environment scheme options and short-term climate change on plant biodiversity in temperate grasslands” in Ecological Solutions and Evidence

Find the other early career researchers and their articles that have been shortlisted for the Georgina Mace Prize 2023 here!