Description
Introduction
The term natural cave refers to any type of underground void that is not of anthropogenic origin. In most cases, natural caves derive from corrosion processes, chemical dissolution of soluble rocks such as limestone, dolomite, marble, gypsum, rock salt, limestone, as well as physical and mechanical erosion processes.
Less represented, but still ascribable to the type of natural caves, are also tectonic cavities (cavities set along fractures or faults and progressively opened under the action of gravity) and lava 'tubes'.
From a purely speleological point of view, for a cave to be defined as such and to be included in a specific cadastre, it must be passable by man, and must have a linear development greater than or equal to 5 m; in addition to this, the transverse dimension of the entrance must not exceed the depth.
CAVE REGISTER
The establishment of the register of caves and karstic areas in the Province of Trento was provided for by Provincial Law no. 37 of 31/10/1983 (Protection of the mineralogical, palaeontological, palethnological, speleological and karstic heritage); Article 14 of the aforementioned law entrusts the Provincial Council with the issuing of regulations concerning the establishment, operation, updating and access to the register itself
The cadastre of Trentino's caves was officially activated on 14 March 2008 by specific resolution of the Provincial Council (the regulations approved by the Council are attached).
The first news of a certain scientific content concerning the caves in our province can be attributed to distinguished naturalists such as Stenone (n. 1638 - m.1686; Bus della Giazzera near Ronzo -Chienis) and Antonio Stoppani (n. 1824 - m. 1891; Pozzi glaciali di Nago e Vezzano).
Historically speaking, however, the cadastre was started in the early years of the last century, mainly by naturalists and geographers, including Cesare Battisti, and hikers affiliated with SAT speleological groups (among the most active were the Mattarello and Riva cave groups). In the period from the 1950s to the present day, the cadastre was initially taken care of by the Tridentine Museum of Natural Sciences and then by the Tridentine Mountaineers' Society, but currently the direct responsibility, based on the aforementioned regulations, is entrusted to the Autonomous Province of Trento and in particular to the Geological Service.
For several years now, the Geological Service has been acquiring data on caves in the province with the collaboration of the Società Alpinisti Tridentini, on the basis of an initial agreement valid for the three-year period 2005 - 2007.
The data collected was verified, integrated and validated with the data and geological information present in the archives of the Geological Service. All the material was finally used to create a computer database that also includes the digitisation of paper and bibliographic information (surveys, photos, previous studies).
The work to be carried out in the coming years is, however, considerable, as the management of the cave cadastre requires continuous work to update, correct and integrate the data, as these are liable to change following new exploratory discoveries or in-depth scientific knowledge of the provincial territory.
The work of updating, correcting and integrating the cadastre data will also be coordinated in the future by the Geological Survey, as required by current regulations, with the collaboration of SAT.
The historical land register currently managed by the Società degli Alpinisti Tridentini has over 2000 caves already catalogued, and it is estimated that there are another 300-400 caves whose exact location is unknown, but their existence is presumed, at least on the basis of information gathered from the inhabitants of towns and valleys or on the basis of reports from hikers. In total, therefore, there are more than 2300 caves in our province of which we have more or less detailed information.
The official PAT cadastre currently includes 1301 caves (considering the 2024 update).
There are several reasons why it is extremely important to provide for the protection of natural caves.
Firstly, it must be said that they are unique and unrepeatable environmental assets, which generally took several hundred thousand years, if not several million years, to reach their current morphological conformation.
Caves are also often connected with karstic hydrogeological systems of considerable potential and very vulnerable to possible sources of pollution. Many towns in our territory draw their water supply from springs connected with karst aquifer systems (e.g. in the peripheral valleys of the Brenta Group).
Caves also have other important scientific, geological, geomorphological, historical-cultural, palaeontological and palethnological aspects. In fact, there is no lack of examples of caves frequented in prehistoric times (Ernesto's Cave in Grigno, Riparo Gaban in Martignano di Trento), in historical times (Bus dei Preeri in Avio, Covelo di Rio Malo in Lavarone, Il Colo in Pieve Tesino, etc.). Important cave sites with findings of Ursus Spelaeus have also been studied. Finally, recent developments in the field of climate reconstructions of the last 500,000 years on the basis of cave deposits (concretions such as stalactites, stalagmites, flows, etc.) should be mentioned.
In the territory of the Province of Trento, well over 100 caves are more than 100 m long, and at least 15 of them are more than 1,000 m long.
The largest is the Grotta della Bigonda, whose entrance is located in the municipality of Ospedaletto, and which exceeds 40 km in length on the northern slope of the Asiago plateau.
More than 50 caves present significant differences in height, between 50 and 400 m. These include the Abisso di Lamar (Terlago), the Abisso di Aladino (Daone) and the Abisso di Val del Parol (Brentonico).
Recently, several explorations of the Abisso del Laresot in the Brenta Group were conducted, during which a depth of the order of 1000m was reached.
As many as 133 of the most significant caves, due to their scientific, historical and cultural importance, have been included in the Provincial Urban Plan among the invariants, as characteristic elements of our territory from an environmental point of view. Special protection criteria should apply to them, overlapping with those already provided for by the regulations in force for all the natural cavities included in the cadastre. It is estimated that with the inclusion of most of the caves known to exist in the cadastre, the number of karstic cavities included in the PUP as 'invariants' could reach and exceed 200.
As far as future activities within the scope of the Cadastre management are concerned, in addition to data updating activities, the execution of geological and stratigraphic studies within the caves, hydrogeological studies for the control and monitoring of groundwater outflows, the reconstruction of hydrogeological models of the major karstic aquifers, and palaeoclimatic reconstructions from cave deposits has been promoted.