Réserve naturelle régionale des cheires et grottes de Volvic: A Volcanic Landscape and Protected Bat Habitat

The reserve is best known for combining two distinctive features of the Auvergne volcanic landscape: the rough cheires lava flows of the Puy de la Nugère, and a network of historic underground quarries that have become the most important hibernation roost for bats in all of Auvergne. It is also recognized for safeguarding key catchment areas that supply the Volvic natural mineral water, making geology, cave ecology, and hydrology tightly linked conservation concerns within a very compact area.

The history of the reserve begins not with nature protection but with stone quarrying. The trachy-andésite stone of the region, marketed throughout France as Pierre de Volvic, was extracted from underground quarries cut into the lava flows of the Puy de la Nugère, with major workings underway before the 19th century. Because the lava cooled around the galleries rather than collapsing, the quarries remained intact long after extraction slowed and gradually turned into stable cavities of archaeological, geological, and ultimately ecological interest.

Recognition of the site's natural and heritage value led to a coordinated protection effort in the early 2010s, culminating in a decision by the Auvergne regional council on 23 September 2014 to classify the area, with formal creation of the reserve on 2 October 2014. The LPO Auvergne was chosen as the managing organization, bringing its regional expertise in ornithology and species conservation to bear on a site where bat conservation was the most urgent ecological priority. Since then, the reserve has functioned as both a conservation site and an outdoor education resource, welcoming visitors on marked paths while keeping the bat caves themselves carefully closed to public access.

The reserve's landscape is defined by the volcanic geology of the Chaîne des Puys. The Puy de la Nugère, a scoria and lava cone typical of the Massif Central, produced the trachy-andésite flows that the reserve protects. These flows, locally known as cheires, form a jagged terrain of dark volcanic rock blocks with thin soils, creating an open, harsh upper surface that contrasts sharply with the gentler farmland and woodland around Volvic.

The surface area combines rocky outcrops and cheires with patches of young forest and small natural meadows. The mineral substrate explains both the slow colonization by vegetation and the unusually rich bedrock scenery. Below this visible terrain, the underground dimension is just as important: three separate quarry systems tunnel through the lava flows, creating a series of stable subterranean cavities that today's visitors do not normally enter but that define the reserve's broader geological identity.

Ecologically, the reserve protects a compact but layered set of habitats. On the surface, the cheires support open, sun-exposed pioneer vegetation and scattered young woodland, while the deeper pockets within the reserve include closed-canopy young forest, small meadows, and rocky microhabitats. The combination of volcanic soils, varied exposure, and protected status gives the site a botanical interest that goes beyond its more famous underground fauna.

Hydrologically, the reserve is tied to the catchment system of the Volvic natural mineral water, with the protected area encompassing parts of the infiltration and recharge zones that feed the famous springs at Volvic. This means the reserve is not only a biodiversity site but also a functional piece of regional water infrastructure, and disturbance or contamination at the surface can have direct implications for the quality of groundwater captured at depth. The ecological value of the reserve lies precisely in this overlap between volcanic geology, cave ecosystems, surface vegetation, and groundwater protection.

The single most important wildlife value of the reserve is its bat population. The three quarries together host around 500 individual bats from roughly fifteen species, of which about nine appear regularly. The dominant species include the greater mouse-eared bat (Myotis myotis), the lesser horseshoe bat, and the greater horseshoe bat. Less common but ecologically important species include the Mediterranean horseshoe bat and Geoffroy's bat, contributing to a chiropteran community of regional significance for hibernation.

Above ground, the reserve also supports a community of forest mammals such as the genet and the European wildcat, both of which depend on the mature and semi-mature woodland elements of the site. The bird community is similarly diverse for such a small protected area and includes woodland species such as the Eurasian treecreeper and the wood warbler, which together signal the value of the reserve's young but structurally varied forest cover. The combination of cave-dwelling bats, forest mammals, and breeding woodland birds gives the reserve a notably broad faunal profile despite its limited area.

From a conservation standpoint, the reserve is significant less for its size than for the rarity of the assets it protects. The hibernation caves hold what is recognized as the most important bat hibernation site in Auvergne, with a species mix that includes protected taxa of European concern. Because the caves are physically closed to public access, the reserve offers bats a hibernation environment shielded from disturbance, an increasingly rare condition in densely populated European landscapes.

At the same time, the reserve contributes to the protection of a strategic groundwater resource. Volvic's mineral water is closely linked to regional identity and to the broader Chaîne des Puys ecosystem, and zonal protection of the recharge area is a fundamental part of how that watershed is managed. Combining strict bat conservation with watershed stewardship makes the reserve a small-scale example of integrated landscape protection in a volcanic region where surface and underground environments are tightly connected.

The cultural dimensions of the reserve are inseparable from the volcanic landscape. The name 'Volvic' is itself a brand of stone and of mineral water, and the quarrying of trachy-andésite before the 19th century gave the region durable architecture, including elements of many historic French monuments. The reserve's caves are therefore not only natural cavities but also a piece of the industrial heritage of central France.

Local terminology reinforces this identity. The word 'cheire,' used in the reserve's official name, is itself a regional Occitan-influenced term for the lava fields of the Chaîne des Puys and carries an identity tied to the Massif Central communities that have lived alongside these flows for centuries. The reserve thus preserves a small but meaningful cultural and emblematic piece of Auvergne's volcanic country, recognized not only for its wildlife but also as part of the heritage character of the Volvic area.

Key points of distinction for the reserve include the protected cheires of the Puy de la Nugère, the three historic underground quarries that now shelter Auvergne's principal bat hibernation colony, and the protected catchment feeding the well-known Volvic natural mineral water. With its young forest, scattered meadows, bat caves, and small surface area, the reserve is a compact example of how volcanic geology, cave biology, and hydrological protection can coexist in a single protected site in the Auvergne region.

As a small protected area with walking trails and closed bat caves, the reserve is most rewarding in spring and summer when the young forest, scattered meadows, and woodland bird community are most active. Spring brings breeding forest birds such as the wood warbler and Eurasian treecreeper into song, while summer offers the best conditions for appreciating the open cheires landscape and the contrast between rugged volcanic terrain and greener surrounding countryside. Autumn is particularly atmospheric for experiencing the volcanic scenery in more muted light. Because the underground bat-bearing cavities are not open to the public, the surface experience changes relatively little across seasons, but wildlife viewing is generally stronger from late spring through early autumn.