Ecological Emergency: Protecting Pollinators to Preserve Biodiversity and Human Life
The massive decline in insect populations, particularly pollinators, in agricultural areas is primarily caused by the intensification of agriculture, including the use of pesticides.[1] This phenomenon constitutes one of the major catastrophes of recent decades.[2] Yet, pollinators play a crucial role for humanity by enabling the reproduction of many flowering plants on which we are essentially dependent.[3] Indeed, many of these plants end up on our plates and depend on pollination, which is mainly carried out by Hymenoptera (bees and wasps).
Vullierens: A Refuge for Threatened Bees
The diversity of pollinators at the castle remained insufficiently documented, and few actions had been taken until now to protect them.[4] To remedy this situation, the Hoffmann family, in conjunction with the castle owners, decided to commission an environmental engineering firm to conduct a study of the site.[5]
Threatened Species
The Vullierens estate is home to five bee species whose status is of concern.[6] Among them:
- Near Threatened (NT) in Switzerland[7]:
- Andrena florea (Bryony Mining Bee)
- Colletes daviesanus (Common Colletes)
- Lasioglossum pygmaeum
- Vulnerable (VU) in Switzerland[8]:
- Andrena fulvida
These last two species are also listed as Near Threatened on the European Red List.[9] Finally, Andrena ovatula is classified as Near Threatened at the European level but remains of least concern in Switzerland.[10]
Fragile Habitats
The majority of these bees are threatened by the fragmentation and decline of their natural habitats. Andrena fulvida and Lasioglossum pygmaeum, for example, have seen their geographical distribution decrease in the country since 2000.
A crucial issue
Preserving and restoring natural habitats beneficial to this group is essential to ensure the survival of these species, while contributing to the overall preservation of biodiversity. Indeed, insects are often at the base of the food chain in ecosystems and therefore represent a very important link for them. With this in mind, Vullierens aims to adopt a more ecological approach and thus participate in the protection of pollinator biodiversity.
The Vullierens environment: An asset for bees
The Vullierens estate is distinguished by its varied natural environments, which constitute a valuable refuge for many bee species. Among them, some are ground-nesting and have very specific diets. [11] For example, Andrena florea depends on bryony (Bryonia), a plant common in the surrounding hedges. [12] Colletes daviesanus, on the other hand, feeds mainly on Asteraceae such as yarrow (Achillea) or chamomile (Tripleurospermum), which are found in iris crops or ornamental gardens. [13]
A correlation between floral richness and bees
The garden of Vullierens Castle has a wide variety of flowers, including, among the most abundant plants, roses, irises, lilies, and daylilies. The roses offer a diversity of varieties and colors, while the irises are present with different species and forms. Lilies, with their large flowers, and daylilies, which generally bloom during the day, also add to the floral diversity.
A positive correlation has been observed between the number of bee species and the diversity of flowering plants on the estate [JR1]. [14] This means that areas rich in floral varieties also tend to harbor larger bee populations. [15] This link is explained by the specific dietary preferences of certain species, known as oligolectic bees. [16]
The more diverse an environment is in flowering plants, the more likely it is to meet the needs of these specialized bees. [17]
Vullierens: Actions underway for the protection of biodiversity
Since 2019, Vullierens Castle has been actively involved in promoting biodiversity by providing resources and shelter to the animal and plant species that contribute to the balance of its gardens (Château de Vullierens, 2024). [18] By continuing to promote environmental management that respects and supports floral diversity, Vullierens will contribute to the preservation of species and the strengthening of biodiversity. The protection of these fragile ecosystems is crucial.
[1] Ollerton, 2017 P.2- and “Determination of environmental variables influencing the biodiversity of pollinating Hymenoptera at Vullierens Castle (VD) and proposal of measures” – Julie ROSSIER
[2] Ollerton, 2017 P.2-“Determination of environmental variables influencing the biodiversity of pollinating Hymenoptera at Vullierens Castle (VD) and proposal of measures” – Julie ROSSIER
[3] (Müller & Pfiffner, 2016) and P.2-“Determination of environmental variables influencing the biodiversity of pollinating Hymenoptera at Vullierens Castle (VD) and proposal of measures” – Julie ROSSIER
[4] [4] P.3-“Determination of environmental variables influencing the biodiversity of pollinating Hymenoptera at Vullierens Castle (VD) and proposal of measures” – Julie ROSSIER
[5] [5] P.3-“Determination of environmental variables influencing the biodiversity of pollinating Hymenoptera at Vullierens Castle (VD) and proposal of measures” – Julie ROSSIER
[6] P.34-“Determination of environmental variables influencing the biodiversity of pollinating Hymenoptera at Vullierens Castle (VD) and proposal of measures” – Julie ROSSIER
[7] IUCN, 2023 and P.34-“Determination of environmental variables influencing the biodiversity of pollinating Hymenoptera at Vullierens Castle (VD) and proposal of measures” – Julie ROSSIER
[8] IUCN, 2023 and P.34-“Determination of environmental variables influencing the biodiversity of pollinating Hymenoptera at Vullierens Castle (VD) and proposal of measures” – Julie ROSSIER
[9] P.34-“Determination of environmental variables influencing the biodiversity of Pollinating Hymenoptera of the Château de Vullierens (VD) and proposed measures – Julie ROSSIER
[10] IUCN, 2023 and P.34 – “Determination of environmental variables influencing the biodiversity of pollinating Hymenoptera at the Château de Vullierens (VD) and proposed measures” – Julie ROSSIER
[11] P35 – “Determination of environmental variables influencing the biodiversity of pollinating Hymenoptera at the Château de Vullierens (VD) and proposed measures” – Julie ROSSIER
[12] P35 – “Determination of environmental variables influencing the biodiversity of pollinating Hymenoptera at the Château de Vullierens (VD) and proposed measures” – Julie ROSSIER
[13] P35 – “Determination of environmental variables influencing the biodiversity of pollinating Hymenoptera at the Château de Vullierens (VD) and proposed measures” – Julie ROSSIER
[14] P41 – “Determination of environmental variables influencing the biodiversity of pollinating Hymenoptera at the Château de Vullierens (VD) and proposed measures” – Julie ROSSIER
[15] P41 – “Determination of environmental variables influencing the biodiversity of pollinating Hymenoptera at the Château de Vullierens (VD) and proposed measures” – Julie ROSSIER
[16] P41 – “Determination of environmental variables influencing the biodiversity of pollinating Hymenoptera at the Château de Vullierens (VD) and proposed measures” – Julie ROSSIER
[17] P41 – “Determination of environmental variables influencing the biodiversity of pollinating Hymenoptera at the Château de Vullierens (VD) and proposed measures” – Julie ROSSIER
[18] [18] P.2 – “Determination of environmental variables influencing the biodiversity of pollinating Hymenoptera at the Château de Vullierens (VD) and proposed measures” – Julie ROSSIER