Abisso Bonetti ("Bonetti Abyss") is a Karst cave in the

municipality A municipality is usually a single administrative division having corporate status and powers of self-government or jurisdiction as granted by national and regional laws to which it is subordinate. The term ''municipality'' may also mean the go ...

Doberdò del Lago Doberdò del Lago ( sl, Doberdob; Bisiacco: ; fur, Dobardò) is a ''comune'' (municipality) in the Italian region Friuli-Venezia Giulia, located about northwest of Trieste and about southwest of Gorizia, and borders the following municipalit ...

(

Gorizia Gorizia (; sl, Gorica , colloquially 'old Gorizia' to distinguish it from Nova Gorica; fur, label= Standard Friulian, Gurize, fur, label= Southeastern Friulian, Guriza; vec, label= Bisiacco, Gorisia; german: Görz ; obsolete English ''Gori ...

, Friuli-Venezia Giulia, Italy), SE from the small village of ''Bonetti'', near Slovenian border (village of '' Nova vas''). The cave is one of the most famous cavities in the

Karst. Anyway, due to its dangerous pit opening, entry is allowed only to expert

cavers Caving – also known as spelunking in the United States and Canada and potholing in the United Kingdom and Ireland – is the recreational pastime of exploring wild cave systems (as distinguished from show caves). In contrast, speleology is ...

with the necessary

equipment Equipment most commonly refers to a set of tool A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task. Although many animals use simple tools, onl ...

for single-rope descend.

Morphology

Abisso Bonetti is one of the biggest and most well-known cavities in the

Karst. It opens above sea level, on a small plateau north of Jamiano (

), near Slovenian border. Overall, it is long and deep. Peculiarity of the cavity is its impressive opening, a deep, for wide abyss, that's an open pit in direct connection with the external environment. The cave has another entrance, that's a partially artificial gallery connected with the pit. During

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

Austro-Hungarian Army The Austro-Hungarian Army (, literally "Ground Forces of the Austro-Hungarians"; , literally "Imperial and Royal Army") was the ground force of the Austro-Hungarian Dual Monarchy from 1867 to 1918. It was composed of three parts: the joint arm ...

built a shelter in the gallery. The bottom part of the open pit contains a rubble slope where detritus,

plant material Vascular tissue is a complex conducting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. There ...

s and animal carrions, fallen down from the external environment, are collected. The innermost part of the cave is made up of an underground gallery after that, passing through a tight passage, a big hall is reached. The hall contains collapsed bedrocks and

cave formations A speleothem (; ) is a geological formation by mineral deposits that accumulate over time in natural caves. Speleothems most commonly form in calcareous caves due to carbonate dissolution reactions. They can take a variety of forms, depending on ...

, including a column that seems like holding up the weight of the ceiling. Abisso Bonetti shows a

climatic Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorological ...

peculiarity. The innermost part of the cave has a stable temperature (, that's the annual mean temperature in the place where the cave opens), a typical feature of cavities. In the bottom part of the open pit, the temperature varies between in summer and in winter. This part of the cave can be considered a

cold trap In vacuum applications, a cold trap is a device that condenses all vapors except the permanent gases into a liquid or solid. The most common objective is to prevent vapors being evacuated from an experiment from entering a vacuum pump where they ...

History

During

, between 1916 and 1917,

used the cave as a shelter and as a field hospital, and adapted it through opening a new entrance in the gallery next to the pit. Because of the present of a number of

pigeons Columbidae () is a bird family consisting of doves and pigeons. It is the only family in the order Columbiformes. These are stout-bodied birds with short necks and short slender bills that in some species feature fleshy ceres. They primarily ...

Austro-Hungarians Austria-Hungary, often referred to as the Austro-Hungarian Empire,, the Dual Monarchy, or Austria, was a constitutional monarchy and great power in Central Europe between 1867 and 1918. It was formed with the Austro-Hungarian Compromise of 1 ...

called the cave ''Taubenloch Höhle'' or ''Taubenschlucht'' ("Pigeons Hole"). The same name ( Slovene: ''Golobinka'') was also used by Slovenian people living in the area. In the spring of 1917,

Italian Army "The safeguard of the republic shall be the supreme law" , colors = , colors_labels = , march = ''Parata d'Eroi'' ("Heroes's parade") by Francesco Pellegrino, ''4 Maggio'' (May 4) ...

occupied the whole area and used the cave as a shelter. In 1946, the ''Rastrellatori'' ("

bomb disposal Bomb disposal is an explosives engineering profession using the process by which hazardous explosive devices are rendered safe. ''Bomb disposal'' is an all-encompassing term to describe the separate, but interrelated functions in the milita ...

") unit extracted a number of explosive remnants of war from the cave. However, some remnants of

can be found in the cave yet. In addition to the military use, the cave has drawn

speleologists Speleology is the scientific study of caves and other karst features, as well as their make-up, structure, physical properties, history, life forms, and the processes by which they form (speleogenesis) and change over time (speleomorphology). ...

' attention. The first

survey Survey may refer to: Statistics and human research * Statistical survey, a method for collecting quantitative information about items in a population * Survey (human research), including opinion polls Spatial measurement * Surveying, the techniq ...

of the cavity was realised by

Colonel Colonel (abbreviated as Col., Col or COL) is a senior military officer rank used in many countries. It is also used in some police forces and paramilitary organizations. In the 17th, 18th and 19th centuries, a colonel was typically in charge o ...

Italo Garibotti (SAG) in January 1923. The survey was reviewed by Ugo Stocker (Gruppo Speleologico

Monfalcone Monfalcone (; Bisiacco: ; fur, Monfalcon; sl, Tržič; archaic german: Falkenberg) is a town and ''comune'' of the province of Gorizia in Friuli Venezia Giulia, northern Italy, located on the Gulf of Trieste. Monfalcone means 'falcon mountain ...

se) on 16 June 1968. During last decades, many speleology schools have used the cave in their first-level courses. Since the 80ths, scientist have carried out a number of botanical, zoological and geological studies and researches in the cave.

The fauna

Abisso Bonetti represents one of the four localities where the

ground beetle Ground beetles are a large, cosmopolitan family of beetles, the Carabidae, with more than 40,000 species worldwide, around 2,000 of which are found in North America and 2,700 in Europe. As of 2015, it is one of the 10 most species-rich animal f ...

'' Typhlotrechus bilimeki tergestinus'', a troglobious, depigmented and anophthalmic

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

species, can be observed. Other species hosted in the cave are cave dwelling species typical of the Karst area.

Troglobites A troglobite (or, formally, troglobiont) is an animal species, or population of a species, strictly bound to underground habitats, such as caves. These are separate from species that mainly live in above-ground habitats but are also able to live u ...

include the spider '' Mesostalita nocturna'', the

woodlouse A woodlouse (plural woodlice) is an isopod crustacean from the polyphyleticThe current consensus is that Oniscidea is actually triphyletic suborder Oniscidea within the order Isopoda. They get their name from often being found in old wood ...

s ''Alpioniscus strasseri'' and ''Androniscus stygius'', and the

round fungus beetle Leiodidae is a family of beetles with around 3800 described species found worldwide. Members of this family are commonly called round fungus beetles due to the globular shape of many species, although some are more elongated in shape. They are g ...

''Bathysciotes khevenhulleri tergestinus''. Troglophiles include the

millipede Millipedes are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments; they are known scientifically as the class Diplopoda, the name derived from this feature. Each double-legged segment is a resu ...

'' Brachydesmus subterraneus'', two centipede lithobid species, the

cave cricket The orthopteran family Rhaphidophoridae of the suborder Ensifera has a worldwide distribution. Common names for these insects include cave wētā, cave crickets, camelback crickets, camel crickets, Hogan bugs, spider crickets (sometimes shorte ...

''Troglophilus neglectus'', the

moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...

Triphosa dubitata ''Triphosa dubitata'', the tissue, is a moth of the family Geometridae. The species was first described by Carl Linnaeus in his 1758 10th edition of ''Systema Naturae''. It is found from north-west Africa across the Palearctic to Japan. The w ...

'', the fly '' Limonia nubeculosa'' and an unidentified

phorid fly The Phoridae are a family of small, hump-backed flies resembling fruit flies. Phorid flies can often be identified by their escape habit of running rapidly across a surface rather than taking to the wing. This behaviour is a source of one of thei ...

species, the

'' Laemostenus cavicola'', and the

rove beetle The rove beetles are a family (Staphylinidae) of beetles, primarily distinguished by their short elytra (wing covers) that typically leave more than half of their abdominal segments exposed. With roughly 63,000 species in thousands of genera, the ...

s ''Atheta spelaea'' e ''Quedius mesomelinus''''.'' In addition,

bat Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most ...

s (in particular the

greater horseshoe bat The greater horseshoe bat (''Rhinolophus ferrumequinum'') is an insectivorous bat of the genus '' Rhinolophus''. Its distribution covers Europe, Northern Africa, Central Asia and Eastern Asia. It is the largest of the horseshoe bats in Europe an ...

''Rhinolophus ferrumequinum'') and birds (e.g. some specimen of

tawny owl The tawny owl (''Strix aluco''), also called the brown owl, is commonly found in woodlands across Europe to western Siberia, and has seven recognized subspecies. It is a stocky, medium-sized owl, whose underparts are pale with dark streaks, a ...

) use the first part of the cavity as a refuge. The bottom part of the open pit hosts a number of

trogloxene Trogloxenes or subtroglophiles, also called cave guests, are animal species which periodically live in underground habitats such as caves or at the very entrance, but cannot live exclusively in such habitats."Cave Plants and Animals". 9 December Am ...

insects, spiders, amphibians and reptiles. In summer, these animals are attracted by low temperature and

humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity dep ...

coming from the pit and fall down. However, if they survive the fall, they stay trapped and cannot return to the external environment.

The flora

In general, the lack of sunlight in caves prevents

photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...

and plant growth. However, the particular morphology of Abisso Bonetti (a deep pit with a large opening) lets a certain amount of light penetrate the pit, allowing the growth of some plant species. Vegetation in Abisso Bonetti can be divided in four vegetational zones, that are from the top (extern) to the bottom (intern) of the pit: * liminal zone (): this well-lighted zone hosts trees and herbs growing in the external environment (typical plants of '' Seslerio- Ostryetum''), and some

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes exce ...

species (genera ''

Asplenium ''Asplenium'' is a genus of about 700 species of ferns, often treated as the only genus in the family Aspleniaceae, though other authors consider '' Hymenasplenium'' separate, based on molecular phylogenetic analysis of DNA sequences, a different ...

'' and ''

Polypodium ''Polypodium'' is a genus of ferns in the family Polypodiaceae, subfamily Polypodioideae, according to the Pteridophyte Phylogeny Group classification of 2016 (PPG I). The genus is widely distributed throughout the world, with the highest ...

'') * sub-liminal zone (): this zone hosts phanerogames (

common hazel ''Corylus avellana'', the common hazel, is a species of flowering plant in the birch family Betulaceae. It is native to Europe and western Asia. It is an important component of the hedgerows that were the traditional field boundaries in lowland En ...

, balm-leaved archangel, wall lettuce,

cyclamen ''Cyclamen'' ( or ) is a genus of 23 species of perennial flowering plants in the family Primulaceae. ''Cyclamen'' species are native to Europe and the Mediterranean Basin east to the Caucasus and Iran, with one species in Somalia. They gro ...

, drooping bittercress),

s ( maidenhair spleenwort and hart's-tongue), mosses (especially ''Thamnobryium alopecurum'') and the first green algae colonies * sub-dark zone (): this zone, where light is strongly reduced, hosts mosses, hepatics and some remaining

s ( maidenhair spleenwort) * dark zone (): only bacteria and green algae colonies can survive here, where light is absent but humidity is high; moreover,

mold A mold () or mould () is one of the structures certain fungi can form. The dust-like, colored appearance of molds is due to the formation of spores containing fungal secondary metabolites. The spores are the dispersal units of the fungi. Not ...

s and

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

(non-photosynthetic organisms) grow on decomposing substances

Geology

In the 90ths, two minerals was found for the first time in an Italian cave. These are

crandallite Crandallite is a calcium aluminium basic phosphate mineral. It has ideal formula . Crandallite was named after Milan L. Crandall, Jr, who worked for Knight Syndicate. This mineral is found in laterite and in alteration products of phosphate rich ...

and

octacalcium phosphate Octacalcium phosphate (sometimes referred to as OCP) is a calcium phosphate with a formula Ca8H2(PO4)6⋅5H2O. OCP may be a precursor to tooth enamel, dentine, and bones. OCP is a precursor of hydroxylapatite (HAP), an inorganic biomineral that ...

(OCP).

References

External links

Infos about the cave on Friuli-Venezia Giulia cave registry
*{{in lang, it}
Survey of the cave
Caves of Italy Limestone caves Landforms of Friuli-Venezia Giulia Province of Gorizia