The Vena del Gesso Romagnola

🧭 Between geology and nature

From a naturalistic point of view, the Vena del Gesso is precious because the gypsum creates poor, draining and often arid soils, with contrasting exposures and microclimates: this favors a mosaic of habitats (arid grasslands, scrub and thermophilic woods, cooler woods on shady slopes, rocky environments) and therefore a very high biodiversity.

🧂 Brief geological history: the Messinian salinity crisis

The origin of the Vena del Gesso is linked to the Messinian salinity crisis, which occurred about 6 million years ago. In that phase, the reduction of exchanges between the Mediterranean and the Atlantic led to strong evaporation and the deposition of thick evaporitic layers: among these, gypsum (selenite). Clay levels (including bituminous clays) also alternate in the deposits, creating stratifications clearly visible in the natural cuts and walls of the park, which in some points reach considerable heights.

Subsequently, tectonic movements and erosion have "exposed" these levels, transforming the Messinian deposits into a continuous and scenic outcrop, today readable as a true whitish "backbone" in the Apennine landscape.

🌿 Flora and fauna (briefly)

Vegetation varies greatly depending on exposure:

• Warm and sunny slopes (south): species more tolerant to drought, with stretches of thermophilic and shrubby vegetation (scrub, junipers and species typical of arid environments).
• Shady and cooler slopes (north): more humid and continuous woods (oaks and other broad-leaved trees), with rich seasonal blooms.

Also relevant in the park area is the "Augusto Rinaldi Ceroni" Herb Garden (Casola Valsenio), known for the presence of numerous medicinal species.

Fauna

The variety of environments supports a rich fauna:

• Mammals: among those reported in the park areas are fox, hare, roe deer, badger and other carnivores/elusive forest animals.
• Avifauna: raptors and forest species linked to the different types of woods and rocky margins.
• Reptiles and amphibians: present thanks to the coexistence of arid areas and cooler/wetter zones.
• Bats: particularly important in hypogean areas (caves), where they find shelter and wintering/breeding sites.

🕳️ Caves and karst in gypsum (the "underground world")

One of the most fascinating aspects of the Vena del Gesso is karst: gypsum is a relatively soluble rock, and water (on the surface and in depth) digs over time a network of cavities, conduits and halls.

In the park, over 200 caves have been surveyed, with a total underground development of over 40 km. In addition to caves, typical karst forms are frequent: sinkholes, swallow holes, blind valleys, springs and vertical "abysses".

Among the most known cavities (some also linked to routes and guided tours) are cited:

• Grotta del Re Tiberio (among the most famous and visitable),
• Tanaccia,
• Ca’ Toresina,
• Abisso Fantini,
• other cavities and hypogean systems of great speleological interest.

The caves are not just "geology": they are also very delicate habitats (stable microclimates, specialized fauna such as bats) and in several cases have returned traces of ancient human frequentations, making the underground heritage important also from a historical-archaeological point of view.