Scientists from INRAE and ANSES have studied vegetation changes in the margins of 500 agricultural plots across mainland France to assess the impact of climate change and farming practices. Their findings, published in Ecology Letters, reveal that over the past decade, average temperatures in these plots have risen by 1.2°C while soil moisture has dropped by 14%.
As a result, plant communities have shifted, favoring heat- and drought-tolerant species over those adapted to farming-related disturbances, according to a press release.
Field margins, which bridge natural habitats and cultivated fields, play a crucial role in biodiversity conservation. They support a mix of weed species, such as cleavers and creeping thistle, alongside grassland plants like common sorrel and meadow vetchling. These areas also serve as vital ecological corridors, providing refuge for beneficial insects and natural pest regulators. Climate-conscious farming practices — including maintaining plant cover, agroforestry, and reducing agricultural inputs — could help preserve biodiversity and enhance resilience to environmental change.
500-Plot Network Tracks Field Margin Biodiversity
In 2012, the Ministry of Agriculture established the 500 ENI biovigilance network under the Ecophyto Plan to track the unintended impacts of farming on field margin biodiversity. The network includes 500 plots representing various farming systems across mainland France, with 20% being organic, and covers three crop types: arable, vines, and market garden produce. From 2013 to 2021, researchers analyzed botanical data, meteorological information from Météo-France (temperature, soil moisture), and farming practice data provided by farmers, including fertilizer and herbicide use, as well as margin vegetation management through mowing.
Pronounced Effects of Climate Change on Agricultural Plots
Their results showed very pronounced changes in the climate of the 500 plots, with an average temperature rise of 1.2°C and a 14% fall in soil moisture over almost 10 years. At the same time, farming practices on the 500 plots did not change significantly, apart from a slight fall in the frequency of mowing field margins.
Depending on the species and the environment in which they live, plants can adopt three basic strategies:
- stress tolerance, linked to the ability of plants to withstand environmental constraints leading to a lack of resources (aridity, infertile soil, etc.),
- competitiveness, to maximise acquisition of the resources needed for rapid growth in favourable environments,
- and the ruderal strategy, which enables plants to withstand disruption to their environment, due mainly to human activities but also to natural events such as flooding.
Each plant can only adopt one strategy at a time, so plant communities reflect the trade-offs between different strategies based on the environmental pressures they face. Over the study period, as climate conditions changed, scientists observed a shift in field margin plant communities, with species using competitive and ruderal strategies declining, while stress-tolerant species increased.
As plant communities adapt to rising temperatures and aridity, they may become less resilient to conventional farming practices. To help preserve their adaptive capacity, climate change mitigation practices — such as plant cover, agroforestry, and reducing agricultural inputs — could support biodiversity and its ability to adapt.
