The research, conducted by Jacopo Franzoni, Dania Cruz-Tejada, Angelino Carta and Lorenzo Peruzzi of the University of Pisa for the first species, and by Franzoni, Antonio Giacò and Peruzzi for the second, forms part of an ongoing series documenting chromosome numbers for the Italian flora. Italy is one of Europe’s richest countries for plant diversity, yet the chromosome counts of many of its species rest on old literature, ambiguous records, or no data at all. Each verified count is a data point that feeds into larger questions about how plants evolve, diversify, and sometimes vanish.

The first target, Crepis suffreniana, is a small annual in the sunflower family with a strikingly fragmented distribution. It occurs in three main areas: the maritime regions of south-western France, parts of south-eastern France, and a single Italian population confined to the Migliarino-San Rossore-Massaciuccoli Regional Park in Tuscany, near Pisa. That Italian population is the species’ entire national foothold, which makes every biological detail about it matter for conservation. The researchers obtained seeds, germinated them, and examined the dividing cells of young root tips—standard practice in plant cytogenetics, because root tips are where cell division is abundant and chromosomes are easiest to observe.

The laboratory protocol is a beautifully tuned routine. Root tips were pre-treated with 0.4% colchicine for three hours, a chemical that halts cell division at metaphase, when chromosomes are most condensed and countable. The tips were then fixed in Carnoy solution, a mixture that preserves cellular architecture, hydrolysed in 1 normal hydrochloric acid at 60 degrees Celsius to soften the tissue, and finally stained with leuco-basic fuchsine, a dye that renders chromosomes a deep, unmistakable purple. Squash preparations—literally flattening the stained tip onto a slide—spread the chromosomes into a single optical plane where they can be tallied one by one.

The verdict for the Tuscan plants: 2n = 8, meaning eight chromosomes in the somatic cells. That number agrees with the classic account published by the great Crepis specialist Babcock in 1947, but it carries a crucial new significance. Babcock never specified whether his original count came from French or Italian material, leaving the Italian population’s cytology undocumented for nearly eight decades. The genus Crepis is famous among cytologists for its chromosomal diversity: within the section Phytodesia, which includes C. suffreniana, eight out of ten species share 2n = 8, while two relatives, C. capillaris and C. fuliginosa, dip to 2n = 6. The new count confirms the Tuscan population sits squarely within the standard pattern of its group, yet it is the first count ever formally documented from Italian plants of this species.

The second result is the one that made botanists sit up. Dianthus furcatus subsp. furcatus, a Mediterranean mountain plant or orophyte of the western Alps, was previously reported in the literature as tetraploid, with 2n = 60 chromosomes—records dating back to Darlington and Wylie’s landmark chromosome atlas of 1956 and Carolin’s work the following year. Those old citations referred generically to Italy and the Alps, without pinpointing populations. When the team counted chromosomes from plants collected on the southern slope of Monte Frontè in Liguria, at an altitude of 1,668 metres among grasslands with protruding rocks, they found a number nobody expected: 2n = 90.

Ninety chromosomes corresponds to a hexaploid level—six complete sets of the basic genome—in this genus, a level not previously documented for the species. Polyploidy, the possession of multiple whole genome copies, is one of the dominant forces in plant evolution, and discovering which ploidy level a population carries can reshape how scientists draw species boundaries, reconstruct migration histories, and design conservation strategies. The hexaploid finding contrasts sharply with previous studies of D. furcatus in the broad sense from the Italian Alps, which had documented only the diploid level, and with the tetraploid reports inherited from mid-twentieth-century compendia. The Corsican endemic D. gyspergerae, considered by some authors a subspecies of D. furcatus, is reported as diploid, further enriching the picture of chromosomal variation across this tangled species complex.

The Italian populations of D. furcatus are organized into three subspecies: the typical form spanning the western Alps, D. furcatus subsp. dissimilis known only from Vallone degli Alberghi in the Maritime Alps of Piedmont, and D. furcatus subsp. lereschii in the Graian Alps. A hexaploid count in the typical subspecies now raises tantalizing questions. Are the populations of subsp. furcatus uniformly hexaploid, or do ploidy levels vary across the Alpine arc? Could older tetraploid records have been based on misidentified material, or on populations that have since been reinterpreted taxonomically? Answering those questions will require the kind of population-by-population sampling this study exemplifies, and it may ultimately require genome size measurements and molecular markers to trace how the polyploid lineages arose and spread.

What makes these two counts compelling beyond specialist circles is the contrast they present. One species shows textbook stability: its eight chromosomes match an eighty-year-old expectation, and the interest lies in finally pinning the record to the plant’s most vulnerable Italian stronghold. The other shows textbook revision: a number enshrined in reference works since the 1950s dissolves on contact with fresh material from a specific Ligurian mountain. Both outcomes are essential. Verified chromosome numbers underpin karyological databases, inform cytotaxonomic treatments of difficult groups, and provide baselines for detecting hybrids and polyploid ecotypes that standard morphology can miss.

The work also highlights the quiet infrastructure of biodiversity science. Each count is anchored to a voucher specimen—catalogued and preserved in the herbarium of the University of Pisa—collected at a precisely recorded location and date, so that any future researcher can retrace the evidence. The Pisa group actively invites contributions of new chromosome data, with submissions directed to Antonio Giacò and required to include voucher details and methods. In an era when genome sequencing grabs headlines, the humble squash preparation of a root tip continues to deliver results that no database can substitute: a direct, physical count of the hereditary units of a living plant. For Crepis suffreniana and Dianthus furcatus subsp. furcatus, those counts now exist on firm ground, and the Italian flora’s genetic atlas is one step closer to complete.

Subject of Research: Chromosome counts of two native Italian plant species, Crepis suffreniana and Dianthus furcatus subsp. furcatus

Article Title: Chromosome numbers for the Italian flora: 18

Article References: Franzoni, J., Cruz-Tejada, D., Carta, A., Giacò, A., & Peruzzi, L. (2026). Chromosome numbers for the Italian flora: 18. Italian Botanist, 21, 233-236. https://doi.org/10.3897/italianbotanist.21.200391

Image Credits: AI Generated

DOI: 10.3897/italianbotanist.21.200391

Keywords: cytogenetics, chromosome numbers, Italian flora, Crepis suffreniana, Dianthus furcatus, polyploidy, hexaploid, plant taxonomy, conservation botany, western Alps, Tuscany, Italian Botanist

The work, published in the journal Scientific Drilling, describes a series of active seismic experiments carried out in the Ossola Valley in support of the International Continental Scientific Drilling Program project known as DIVE, short for Drilling the Ivrea–Verbano zonE. Led by Andrew Greenwood of the University of Lausanne and Montanuniversität Leoben, together with colleagues from Switzerland, Italy, and Austria, the campaign was designed to characterize the subsurface at two proposed borehole sites, one near the town of Ornavasso and another at Megolo di Mezzo. The planned boreholes, each roughly one kilometer long, will penetrate the upper reaches of the lower continental crust, a zone that normally lies hidden many tens of kilometers beneath our feet.

The scientific stakes are considerable. Drilling is the only way to recover continuous fresh rock cores from the deepest, non-exposed portions of the Ivrea crustal section, and the DIVE project aims to answer long-standing questions about the composition, structure, and physical and chemical properties of the lower continental crust. The project also intends to explore potential microbiological niches in these deep rocks, probing for life in one of the planet’s most extreme rock environments. Phase I of DIVE targets two complementary sections of the lower crust, while a future phase II in the neighboring Sesia Valley aims even higher, with plans to drill through the crust–mantle boundary itself, the Moho.

Before any of that could happen, the team needed to know exactly what lies beneath the valley floor. Surface geology is mapped in exquisite detail in the Ivrea–Verbano zone, and the steep topography allows some downward extrapolation of structures, but the researchers needed to bridge a stubborn gap in scale between regional geophysical images, which resolve features on the scale of kilometers, and the centimeter-to-meter scale information that borehole instruments will eventually provide. Active seismic reflection surveying, in which a controlled seismic source sends waves into the ground and geophones record the echoes that bounce back from subsurface layer boundaries, was the tool of choice.

Conducting the surveys, under the project name MicrO-SEIZE, was no simple matter. The Ossola Valley is a deep glacial valley flanked by steep mountain slopes inclined at roughly 25 to 30 degrees and cloaked in dense vegetation. The valley floor hosts pastures, the Toce River, major roads, railways, and water canals, all of which constrain where instruments could be placed and all of which generate anthropogenic noise that contaminates seismic recordings. Over 12 days in June 2019, the team deployed a 12,247-kilogram EnviroVibe vibrator truck, sweeping frequencies from 12.5 to 150 hertz over 12 seconds at each source point. Geophones with a resonant frequency of 15 hertz were planted along roads, disused highways, and open fields, connected to cabled acquisition systems totaling hundreds of channels.

To cope with the complex, steeply dipping geology, the team employed a crossed-array method, combining a central receiver line oriented across the strike of the target structures with shorter orthogonal crosslines. This arrangement provided sparse three-dimensional coverage and allowed the researchers to capture reflections dipping obliquely to the main profile. Where sources and receivers were closely co-located, the seismic fold, a measure of how many independent measurements contribute to each image point, reached values as high as 70, and up to 195 at the center of the Ornavasso primary profile. A supplementary ultra-high-resolution survey, dubbed nanO-SEIZE, used a 35-kilogram portable vibrator and geophones spaced just 1.5 meters apart to characterize the immediate vicinity of the Ornavasso drill site right up to an adjoining cliff face.

The processing chain was rigorous and iterative. After vibroseis correlation, trace editing, filtering, deconvolution, and velocity analysis, the team built site-specific velocity models for each profile. Refraction analysis of first-arrival times revealed a simple two-layer near-surface structure: a thin veneer of dry sediments, only about 5 to 10 meters thick, overlying water-saturated sediments with an average velocity of 1,520 meters per second. Constant-velocity stack tests refined the stacking velocities, and a velocity gradient of 0.00167 per meter proved capable of coherently imaging horizontal reflectors down to roughly 500 meters. For the Megolo profile, which runs nearly parallel to the valley walls and to the dipping rock fabric, the team went further and constructed a full three-dimensional velocity model, using a representative metagabbro velocity of 7,000 meters per second derived from field samples and published laboratory measurements.

The results delivered a striking picture of the valley itself. Along the transect running from Premosello–Chiovenda toward Megolo, the seismic sections revealed a wide, U-shaped glacial valley carved into crystalline bedrock, with the trough centered beneath the middle of the Ossola Valley. The base of the Quaternary glacial and glacioflacial sediments sits at approximately 550 meters depth, equivalent to about 300 meters below sea level. Within the sedimentary fill, the reflectors are far from simple: irregular, onlapping layering points to thick proglacial lake sediments preserved from older glacial cycles, along with evidence of paleochannels left behind as the Toce River meandered across the valley floor. At the two drill sites themselves, the sedimentary overburden was found to be up to 50 meters thick, and the surveys prompted a practical adjustment: the Ornavasso borehole location has been moved roughly 20 meters closer to an exposed bedrock cliff to minimize the amount of soft sediment the drill must pass through and to better target the axis of the tightly folded Massone Antiform.

Equally important was what the surveys revealed about the drilling targets themselves. At Megolo, where an inclined borehole is planned to cross the flank of the broad Proman Anticline, the seismic data confirmed the east-southeast dip of the metagabbroic rocks at roughly 20 degrees and guided the planned borehole inclination of 15 to 20 degrees from vertical, ensuring the hole will cross the rock layering as orthogonally as possible and reach the deepest structural levels achievable. At Ornavasso, the target is the hinge of the narrow Massone Antiform, and a near-vertical borehole is planned. Critically, the surveys found no evidence of major geological drilling hazards: no shallow-dipping reflectors indicative of large open-fracture systems, fault zones, or cataclastic zones were observed in the crystalline basement at either site, although the geometry of the surveys means that steeply inclined faults cannot be entirely excluded.

The surveys also exposed a fundamental challenge of imaging crystalline terrains. The Ivrea lower crustal rocks have very low acoustic impedance contrasts between conformable layers, with reflection coefficients below 0.05, so the basement rocks return almost no coherent specular reflections. Only the gently dipping fabric of the Proman Anticline, where the target rocks lie close to the surface, could be directly imaged. Elsewhere, the team relied on secondary indicators such as diffraction tails from steeply dipping irregular surfaces and sharp terminations. With the borehole geometries now determined and agreed upon, drilling can proceed, and the seismic database will serve as an essential reference for interpreting the forthcoming borehole logging results, complemented by two years of passive seismic monitoring from the DIVEnet network of 12 stations surrounding the sites. What began as a practical site-characterization exercise has thus produced a detailed portrait of a glacial valley and its hidden bedrock, setting the stage for humanity’s closest look yet at the deep roots of the continents.

Subject of Research: Active seismic characterization of drilling targets in the Ivrea–Verbano zone for the ICDP DIVE continental drilling project

Article Title: Active seismic surveys for drilling target characterization in Ossola Valley: International Continental Scientific Drilling Program (ICDP) project Drilling the Ivrea–Verbano zonE (DIVE) phase I

Article References: Greenwood, A., Hetényi, G., Baron, L., Zanetti, A., Müntener, O., & the MOS field team (2024). Active seismic surveys for drilling target characterization in Ossola Valley: International Continental Scientific Drilling Program (ICDP) project Drilling the Ivrea–Verbano zonE (DIVE) phase I. Scientific Drilling, 33(2), 219-236. https://doi.org/10.5194/sd-33-219-2024

Image Credits: AI Generated

DOI: 10.5194/sd-33-219-2024

Keywords: Ivrea–Verbano zone, scientific drilling, ICDP, seismic reflection, lower continental crust, Ossola Valley, DIVE project, glacial sediments, Moho, geophysics, borehole characterization, Western Alps

The mines at Crocette and Pestarena tell a story that stretches back to the end of the thirteenth century, when the first official documents recorded underground gold mining in the valley. Operations continued into the mid-twentieth century, ending at Pestarena in 1961 as ore grades declined and costs rose. The gold was locked in quartz-carbonate veins hosted in paragneisses and micaschists at Pestarena and in orthogneisses at Crocette, where it occurred alongside sulfide minerals, chiefly pyrite and arsenopyrite, with lesser galena, sphalerite, pyrrhotite and chalcopyrite. Extraction relied on mercury amalgamation and, from the late 1880s, cyanidation, both of which generated enormous quantities of waste rock and fine-grained tailings that were dumped around the processing plants with little regard for the consequences.

That carelessness left a lasting mark. Sulfide minerals in the exposed waste oxidize when they meet air and water, generating acid or neutral mine drainage that mobilizes potentially toxic elements into soils, groundwater and streams. Previous investigations had already documented alarming conditions: soils near Crocette with arsenic concentrations ranging from 145 to more than 40,000 milligrams per kilogram, a natural background value for the area calculated at 477 milligrams per kilogram against an Italian regulatory threshold of just 20 to 50, and surface waters in the most contaminated samples reaching 279 micrograms of arsenic per liter, far above the Italian limit of 10. A 2025 study by members of the same team found that three quarters of groundwater and surface water samples at the two sites were contaminated with arsenic, with other elements exceeding thresholds in groundwater downstream of the tailings.

To build a complete picture, the researchers merged decades of earlier geochemical and mineralogical data with a new sampling campaign conducted in May and July 2024, collecting 28 fresh samples of waste rock, tailings, soil and sediment from depths of up to 30 centimeters. The new material was analyzed at an accredited laboratory using a four-acid digestion followed by inductively coupled plasma emission spectroscopy and mass spectrometry, covering more than fifty elements, while mineralogy was resolved with X-ray powder diffraction and scanning electron microscopy. Because decades of erosion and dispersion have blurred the boundary between waste and native soil, the team classified every sample under two scenarios: a conservative one counting only material clearly located on waste dumps, and a broader one that also included adjacent, vegetation-free or chemically distinctive material, mirroring the distinction between indicated and inferred resources in resource estimation.

The mineralogical work revealed the fingerprints of intense chemical weathering. Alongside the dominant quartz, feldspars and micas inherited from the host rocks, the waste contains secondary minerals that record the breakdown of the original sulfides: scorodite, formed from the alteration of arsenopyrite; jarosite, precipitated as pyrite and pyrrhotite oxidize; and alunite, produced during the alteration of aluminosilicates. Electron microscopy also identified grains of monazite-(Ce), a phosphate mineral that can carry up to seventy percent rare earth oxides, dominated by cerium with significant lanthanum, praseodymium and neodymium, along with traces of residual arsenopyrite, ilmenite, zircon and barite. Scheelite, a calcium tungstate and one of the world’s principal tungsten ores, appeared among the minor minerals, a hint of the critical metals hiding in plain sight.

When the researchers normalized their measured concentrations against the composition of the upper continental crust, the scale of the enrichment became striking. At Pestarena, arsenic in the waste is a median of roughly 1,700 to 2,000 times more abundant than in average crustal rock, while bismuth, tungsten and antimony show median enrichments of about 100, 35 and 15 respectively, with slight enrichment of beryllium and of the light rare earth elements lanthanum, cerium, praseodymium and neodymium. At Crocette the picture is even more dramatic: arsenic reaches a median enrichment of around 4,000 times crustal values, followed by tungsten at 50, antimony at 40 and bismuth at 26. These figures matter because arsenic, bismuth, antimony and tungsten all appear on the European Union’s list of critical raw materials, the strategic elements underpinning semiconductors, photovoltaics, clean energy technologies and defense applications.

The same waste that concentrates these valuable elements also drives the environmental damage, and the team quantified that damage using standard contamination indices. River sediments collected away from the mine workings proved uncontaminated, but sediments from the drainage channels of the mine tunnels and the tailings outflows showed heavy to extreme arsenic contamination, moderate to heavy lead contamination and high ecological risk, driven overwhelmingly by arsenic. In the surrounding soils, the geo-accumulation index placed Pestarena in the heavily to extremely contaminated category for arsenic, with a mean value of 3.5 and individual samples exceeding 5.0, alongside moderate lead contamination, while Crocette soils fell in the moderately to heavily contaminated range. The potential ecological risk index, which weights each element by its toxicity, averaged 296.4 at Pestarena and 251.1 at Crocette, both within the moderate risk category, with arsenic contributing the dominant share, followed by lead and cobalt.

What elevates the study beyond a conventional contamination survey is its economic framing. By estimating the volumes of waste rock and tailings at each site from field observations and stratigraphic data, and applying bulk densities of 1.5 grams per cubic centimeter for waste rock and 1.8 for tailings, the researchers calculated the residual quantities of arsenic, bismuth, antimony and tungsten still locked in the dumps. They then multiplied these quantities by plausible recovery rates of 60 to 80 percent, consistent with efficiencies of 77 to 99 percent reported for tungsten, 81 to 99 percent for arsenic, up to 98 percent for antimony and 76 to 99 percent for bismuth in comparable secondary resources, and by average market prices from 2000 to 2021. Arsenic emerges as the most abundant target, with bismuth, antimony and tungsten present in significant quantities, although the authors stress that these preliminary estimates cannot by themselves establish economic feasibility, since remediation, processing and residue disposal costs must all be weighed against revenues.

The technical pathways for such recovery already exist. Published case studies describe arsenic and antimony extraction from antimony flotation waste by acid leaching, the recovery of antimony and bismuth from copper smelter flue dusts through acid chloride leaching and selective precipitation, the stabilization of arsenic as crystalline scorodite during copper electrorefining, and the recovery of tungsten and arsenic from tungsten-bearing residues using alkaline leaching with pressure oxidation, deep eutectic solvents paired with electrodialysis, or acid leaching followed by solvent extraction. Arsenic occupies a paradoxical position in this landscape: it is both a valuable resource, essential for gallium arsenide semiconductors and electronic technologies, and one of the world’s most notorious poisons, capable of causing severe chronic health effects through contaminated water and food. Any recovery scheme must therefore be paired with safe long-term management of the arsenic left behind, for example by precipitation as scorodite or vitrification, to prevent the problem simply migrating from one waste heap to another.

The broader message is one of reframing. Within the European Union, mining and quarrying generated nearly 500 million tonnes of waste in 2022, the second largest share of any economic activity, and the Circular Economy Action Plan together with the Critical Raw Materials Act now explicitly encourages treating old waste heaps as anthropogenic deposits rather than burdens. The Anzasca Valley study suggests that remediation and resource recovery need not be opposing goals: excavating and processing contaminated waste can simultaneously reduce ecological risk, clean up soils and water, and supply strategic materials that Europe currently imports at geopolitical peril. The authors caution that further work is needed to characterize the materials more precisely, optimize treatment processes and evaluate the full economic and environmental sustainability of recovery strategies. But their central conclusion is clear: the mountains of waste left behind by a thousand years of Alpine gold mining may yet prove to be among the most valuable things those mines ever produced.

Subject of Research: Environmental impact assessment and critical raw material recovery from abandoned gold mining waste in the Western Alps

Article Title: From environmental burden to resource potential: environmental impact evaluation and Critical Raw Materials recovery from abandoned gold mining waste in the Western Alps (NW Italy)

Article References: Zaniboni, L., Cavallo, A., De Luca, D. A., Lasagna, M., Padoan, E., Martin, M., & Dino, G. A. (2026). From environmental burden to resource potential: environmental impact evaluation and Critical Raw Materials recovery from abandoned gold mining waste in the Western Alps (NW Italy). Environmental Science and Pollution Research. https://doi.org/10.1007/s11356-026-38241-6

Image Credits: AI Generated

DOI: 10.1007/s11356-026-38241-6

Keywords: critical raw materials, arsenic, gold mining, mine waste, tailings, circular economy, environmental contamination, ecological risk, Western Alps, Italy, tungsten, antimony