Using Different Grazing Practices for Increasing Plant Biodiversity in the Dykes and Embankments Along the Rhône River (Southern France).

The research explores the impact of different grazing practices on plant biodiversity in the dykes and embankments along the Rhône River in Southern France. Using a variety of grazing systems, the study finds that extensive grazing can increase plant diversity compared to no management or cutting, with the caveat that these benefits only persist if the grazing practices are sustained and adapted as necessary.

Context and Objective

• The study was carried out in Southern France along the Rhône River where extensive grazing by domestic herbivores has been practiced since the 1980s.
• This practice aims to maintain open habitats and enhance biodiversity in European agro-ecosystems such as semi-natural grasslands, mostly put to use in ecosystems of high cultural value.
• This study, however, examines the effects of grazing management in highly anthropized ecosystems like the new ecosystems created by industrial or urban conversions.
• The objective is to find the best way to maintain and manage these new habitats, created by thousands of hectares of dams and dykes built for navigation and electricity production in the 1950s, and naturally colonized by diverse plant communities.

Methodology

• The study started in 1999 and involved the use of different low-intensity grazing management systems involving rustic breeds of cattle, horses, and goats.
• These systems were implemented on a protected reserve of 1454 hectares located in the lower part of the Rhône river.

Findings

• Observations indicate that extensive grazing, as compared to cutting or no management, positively modified vegetation heterogeneity (beta-diversty), and improved the presence of target grassland species.
• However, the grazing management had no impact on plant species richness (alpha-diversity).

Conclusion and Recommendations

• The research concluded that the benefits of grazing will only be confirmed if low-intensity grazing systems are sustained.
• It was also recommended for these systems to be adaptable, such as the use of mixed stocking and the establishment of multiyear contracts with breeders to ensure the continuity and sustainability of these benefits.