The technical core of the study rests on a classic but still indispensable method: the chromosome squash preparation. For most of the species examined, researchers germinated seeds in the laboratory and harvested root tips, the regions of most active cell division. These tips were pre-treated with a colchicine solution, either 0.3% or 0.4% depending on the laboratory protocol, for about three hours. Colchicine disrupts the spindle fibers that normally pull chromosomes apart during cell division, effectively arresting cells in metaphase, the stage at which chromosomes are most condensed and easiest to count. The tissue was then fixed in Carnoy solution, an ethanol and acetic acid mixture that preserves cellular architecture, before hydrolysis in hydrochloric acid at 60 degrees Celsius and staining with Schiff reagent or leuco-basic fuchsine, dyes that bind specifically to DNA. The result is a single-layer preparation in which each cell’s chromosome complement can be observed and counted under the microscope.

The first of the new counts concerns Damasonium alisma, a striking aquatic plant of the water-plantain family, sampled from a temporary Mediterranean pond at Funtana Satoa on the island of Sardinia. The team counted 2n = 28 chromosomes, confirming that the Sardinian plants are tetraploid, with four copies of the basic chromosome set. This aligns with the established understanding that D. alisma is a tetraploid species distributed across England, France, Italy, Portugal, Russia, and Ukraine, and is considered the northern counterpart of the diploid D. bourgaei, which has 2n = 14. The finding matters because a previous count from Sicily, reported decades ago under a different name, showed a diploid number, and D. bourgaei itself has been recorded in Sicily. That raises the possibility of a misidentification in the earlier Sicilian record. The authors argue that clarifying the true distribution of these two taxa in Italy will require a more in-depth study combining morphological and karyological evidence.

Sardinian temporary ponds yielded another first: the chromosome number of Helosciadium crassipes, an umbellifer found in shallow seasonal wetlands that flood in winter or late spring. These habitats belong to a vegetation alliance associated with habitat 3120 of the European Habitats Directive, which protects oligotrophic waters with amphibious vegetation, a priority conservation type. Until now, the species’ chromosome number was entirely unknown. The count of 2n = 22, obtained from plants collected at Perdiana in the province of Oristano, fits neatly with numbers reported for the closely related H. inundatum species group and for most other members of the genera Helosciadium and Apium. For a plant whose wetland habitats are among Europe’s most threatened, even this basic piece of biological information adds to the foundation needed for conservation planning.

The mountain floras of southern and northern Italy contributed their own surprises, particularly among the hawkweeds of the genus Hieracium, a group notorious for its complexity. Hieracium terraccianoi, a hemicryptophytic herb endemic to the Calabrian side of the Pollino Massif within Pollino National Park, was counted for the first time from material gathered at the species’ type locality. The result, 2n = 36, corresponds to a tetraploid level and agrees with counts available for other members of Hieracium sect. Grovesiana, a cluster of similar morphotypes that has challenged botanists for decades.

Three more hawkweed counts, all yielding 2n = 27, or a triploid level, further illuminate this intricate genus. Hieracium hypochoeroides subsp. cilentanum, a rock-dwelling endemic of Monte Cervati in Campania counted at 1,860 meters elevation, belongs to an aggregate of apomictic taxa that likely evolved during the post-glacial period, many of them narrow endemics that survived as relicts in southern Europe. Apomixis, the asexual production of seeds without fertilization, allows triploid plants to reproduce despite their odd chromosome number, which would normally render them sterile. Hieracium lesimanum and Hieracium scopolioides, both endemic to Mount Lesima in the Ligurian Apennines and both known only from their type localities on the mountain’s northern slope, were also found to be triploid. For H. scopolioides, the count is consistent with the only known ploidy estimate in its section, while H. lesimanum’s number matches observations in related taxa of the H. prenanthoidea group in Europe. The repeated pattern of triploidy in these young, range-restricted endemics supports the view that apomictic reproduction has been a major engine of diversification in this genus, generating distinct lineages without the need for sexual recombination.

The carnation family contributed two notable results. Dianthus carthusianorum subsp. tenorei, a subspecies endemic to Italy and distributed through the southern-central Apennines from Marche to Calabria, was counted for the first time from material collected at Monte Pollino at 2,000 meters. The standard count of 2n = 30 confirms the numbers obtained for other subspecies in Italy and central-eastern Europe. Intriguingly, the researchers also spotted cells with 2n = 60 chromosomes within the same root tip, a phenomenon known as endopolyploidy, in which cells duplicate their DNA without dividing. Endopolyploidy is common in many Dianthus species and, while it does not change the germ line’s genetic makeup, it reflects an additional layer of genomic flexibility in this charismatic genus of ornamental and wild flowers.

The second caryophyllid finding concerns Illecebrum verticillatum, a sub-Atlantic species of temporary ponds across Europe and North Africa. In Italy, the plant occurs in Piedmont, Sardinia, and Tuscany, and the Tuscan populations are particularly rare, with recent confirmations restricted to a single area at Montalbano in the municipality of Carmignano. Material from that area showed 2n = 10, a low chromosome number already known from elsewhere in Europe but recorded here for the first time in Italian populations. Meanwhile, in Piedmont, the team obtained the first Italian count for Crupina vulgaris, a widespread southern European composite sampled near Acqui Terme. The result, 2n = 30, matches counts from other European populations and provides a useful reference point for distinguishing the species from its relatives: the more Mediterranean C. crupinastrum has 2n = 28, while C. intermedia, an allopolyploid of hybrid origin, has 2n = 58. Because these species overlap in Italy, chromosome data offer a critical line of evidence for identifying plants and tracing how hybridization has shaped the group’s evolution.

What emerges from this cumulative exercise is a portrait of the Italian flora as a laboratory of evolutionary processes. Polyploidy, apomixis, endopolyploidy, and hybridization each leave fingerprints in chromosome numbers, and every new count helps place a species on the map of these processes. Tetraploid aquatic plants in Sardinian ponds, triploid hawkweeds clinging to Apennine and Apuan summits, and diploid rarities in disappearing wetlands each tell a story about how lineages originate, persist, and sometimes retreat to the edges of their former ranges. Chromosome counts also have immediate practical value: they help resolve taxonomic ambiguities, flag likely misidentifications in old records, and inform conservation assessments for narrow endemics whose entire known range may span a single mountain slope or a single pond.

The study is the thirteenth contribution to a long-running series dedicated to chromosome numbers for the Italian flora, and the series continues to accept new data. Researchers are invited to submit contributions including voucher specimens and methods, ensuring that each count remains traceable to a physical herbarium or germplasm record. That rigor, with seeds deposited in germplasm banks and herbarium specimens preserved for verification, is what transforms a simple count of chromosomes into durable scientific evidence. As Mediterranean temporary ponds shrink and mountain endemics face shifting climates, documenting the genomic architecture of Italy’s plants is not merely bookkeeping. It is a race to understand, and ultimately to protect, a living heritage written in chromosomes.

Subject of Research: Chromosome numbers of plant taxa in the Italian flora

Article Title: Chromosome numbers for the Italian flora: 13

Article References: Astuti, G., Bagella, S., Bajona, E., Barone, G., Becca, G., Caria, M. C., Di Gristina, E., Fainelli, F., Franzoni, J., Giacò, A., Orsenigo, S., Paliy, M., Rivieccio, G., Urbani, M., & Peruzzi, L. (2023). Chromosome numbers for the Italian flora: 13. Italian Botanist, 16, 135-148. https://doi.org/10.3897/italianbotanist.16.116700

Image Credits: AI Generated

DOI: 10.3897/italianbotanist.16.116700

Keywords: chromosome counts, Italian flora, cytogenetics, polyploidy, apomixis, Hieracium, endemic plants, Sardinia, temporary ponds, Dianthus, plant taxonomy, karyology

Wetlands are a cornerstone of Mediterranean biodiversity, and Sicily stands out for the extraordinary heterogeneity of its wetland biotopes. The island’s mountain wetlands carry particular biogeographic weight: the Sphagnum-transitional mires of the Madonie are the southernmost in Europe, while wet meadows and springs host hygrophilous plant communities endemic to southern Italy. Temporary ponds, whose water balance swings between rainy winters and dry summers, have driven the evolution of aquatic plant communities found nowhere else. Yet while the flora of most Sicilian mountains has been well studied, the vegetation of mountain wetlands remains scarce or outdated in many areas, a knowledge gap that recent surveys have begun to close through the discovery of new plant communities in previously little-known localities.

The study focused on two mountain sectors. In the Madonie, within the municipality of San Mauro Castelverde in the province of Palermo, six sites comprising springs and peat bogs were surveyed on flat ground at the foothills of Cozzo Signorina and Pizzo Voturo. In the Nebrodi, eight sites were investigated within the municipality of Mistretta in the province of Messina, including three temporary ponds and five springs and peaty springs distributed on the northern and southern slopes of Monte Castelli. The sites range in altitude from roughly 800 to more than 1,300 meters above sea level, and in area from about 200 to over 3,000 square meters.

Geology plays a decisive role in why these wetlands exist at all. The Madonie sites sit on Upper Oligocene to Lower Miocene formations of dark grey mudstones, brown clays, and thick beds of yellowish quartzarenites, in contact with marly clays and micaceous quartz siltstones of the Lower Miocene. The Nebrodi sites lie on Upper Miocene deposits of grey sands and clayey sands with rare marly outcrops. Fine-grained arenaceous substrates limit rainwater percolation and promote the retention of groundwater, a mechanism also observed in wetland sites of the Apennines, allowing water to pool and saturate the surface long enough for distinctive vegetation to establish.

The fieldwork, carried out in June and July 2025 at the phenological peak of most species, combined vegetation recording with direct hydrochemical measurement. Because water pH and electrical conductivity were measured in every plot, the researchers selected a plot size of one square meter, smaller than the four square meters generally recommended for aquatic vegetation, in order to obtain a more precise relationship between plant composition and the measured abiotic variables. Portable instruments recorded pH and conductivity in the field, and stand topography, whether flat or in a depression, was noted for each plot. Plots were randomly distributed within physiognomically homogeneous areas with uniform slope, topography, and water table conditions.

The data analysis relied on constrained correspondence analysis, a unimodal ordination method appropriate for compositional gradients spanning 7.4 standard deviation units. The ordination model, built on pH, electrical conductivity, and topography, explained 19.74 percent of the total variation in species composition, with the first axis alone accounting for 9.28 percent. A variation partitioning test showed that topography and the hydrochemical variables each explained 7.3 percent of community variability, with virtually no overlap between their explanatory power. Permutation tests confirmed that all environmental variables played a significant role in shaping community composition, and species fidelity calculations using the Phi coefficient with Fisher’s exact test verified the floristic distinctiveness of the groups the ordination distinguished.

The most striking result was the power of topography as an ecological filter. Plots on flat stands, which are springs fed by groundwater or silted-up ponds, separated clearly from plots in depressions, which are temporary ponds and shady pools mostly fed by rainwater. Flat stands remain permanently or semi-permanently water-saturated during the growing season, while depression stands dry out for most of the summer after storing a larger water volume from winter to early summer. The two groups also differed in biological form spectra: although both were dominated by hemicryptophytes, rooted hydrophytes were far more frequent in the depression group at 36 percent compared with 4.5 percent in the flat group, and the flat group was notably richer in species, hosting 65 species against 25, probably because its biotopes offer a wider spectrum of ecological niches and lie in close contact with xeric grasslands.

On the flat, groundwater-fed sites, the vegetation belonged to the alliance Dactylorhizo sacciferae-Juncion striati, characterizing mountain humid swards of Calabria and Sicily that differ from their central European counterparts by the presence of several thermophilous differential species. Among the communities described here are peaty meadows dominated by Juncus articulatus with high cover and a moss layer, fen grasslands with summer dryness co-dominated by Juncus inflexus and Carex otrubae, wet meadows of the tall tufted grass Deschampsia cespitosa representing the driest successional stage, flooded meadows on clay-rich substrates with alkaline pH dominated by Cyperus longus, and peaty-clay wet meadows characterized by the tall sedge Carex acutiformis together with the orchid Dactylorhiza maculata subsp. saccifera. Slightly acidic peaty spring communities with Carex punctata showed the lowest electrical conductivity values, reflecting markedly peaty substrates where organic matter decomposition produces organic acids.

In the depressions, the vegetation belonged to the Sicilian endemic alliance Alopecuro-Glycerion spicatae, which includes upland marshy communities dominated by rooted hydrophytes such as Glyceria spicata and Peplis portula forming dense mats with only their terminal parts emerging. Annual aquatic communities of shallow temporary ponds with silty-clay bottoms were assigned to Glycerio spicatae-Oenanthetum aquaticae, where vegetation phenology tracks pond seasonality: ponds are covered only by Glyceria spicata through winter until late spring, when the robust Oenanthe aquatica starts growing, and the whole community declines and disappears as ponds dry from mid to late summer. Small shaded pools at spring margins hosted floating mats of Callitriche stagnalis with Ranunculus omiophyllus in slightly acidic water with conductivity below 130 microsiemens per centimeter, while flooded pond shores supported communities of Eleocharis palustris with constant Oenanthe fistulosa. Notably, two neighboring ponds differing in hydrochemistry, one alkaline with conductivity above 750 microsiemens per centimeter and one neutral below 232, possibly reflect different cattle densities causing eutrophication.

Beyond their scientific novelty, these wetlands serve as essential refugia for microalgal communities, amphibians, and associated terrestrial vertebrates, and the georeferenced floristic data provide a foundation for biodiversity databases and targeted conservation regulation. The threats are real: some sites suffer from water subtraction and uncontrolled grazing, where livestock urine released into small temporary ponds increases salinity in waters with limited mixing, and trampling damages springs and peatlands, disrupts surface hydrology, and promotes eutrophication. Such pressures facilitate the invasion of nitrophilous species, leading to floristic homogenization and accelerated successional processes that result in wetland infilling. The survey demonstrates that field investigations collecting information on vegetation, flora, and environmental features remain crucial for the conservation of wetland habitats, and that similar ecological contexts in the Sicilian and southern Italian mountains deserve urgent future investigation.

Subject of Research: Vegetation ecology and hydrochemistry of newly discovered mountain wetlands in Sicily

Article Title: Vegetation survey and hydrochemical characterization of newly discovered mountain wetlands in the Madonie and Nebrodi mountains (Sicily)

Article References: Bajona, E., Raimondo, F. M., Di Gristina, E., Domina, G., Pardi, R., & Cirlincione, F. (2026). Vegetation survey and hydrochemical characterization of newly discovered mountain wetlands in the Madonie and Nebrodi mountains (Sicily). Italian Botanist, 21, 81-107. https://doi.org/10.3897/italianbotanist.21.171191

Image Credits: AI Generated

DOI: 10.3897/italianbotanist.21.171191

Keywords: Sicily, Madonie, Nebrodi, mountain wetlands, temporary ponds, peaty springs, plant communities, vegetation survey, hydrochemistry, biodiversity conservation, Mediterranean Basin, phytosociology

The research, conducted by Davide Taurozzi and Massimiliano Scalici of the University of Roma Tre, focused on two contrasting pond networks. Twelve ponds sit within the Castelporziano Presidential Estate, a strictly protected Mediterranean coastal area near Rome where public access is tightly restricted. Twelve more dot the Campo Imperatore plateau in the Gran Sasso and Monti Della Laga National Park, a high-altitude alpine environment where ponds are regularly visited by tourists and grazed by livestock. By pairing these two systems, the authors were able to ask a deceptively simple question: what happens to the ecological condition of temporary ponds when one set is shielded from human pressure and the other is not?

The answer came from diatoms, single-celled algae encased in ornate silica shells that cling to sediments, stones and submerged vegetation. Diatoms are prized in freshwater science because individual species carry precise ecological preferences. Some thrive in nutrient-rich, polluted water, while others tolerate only clean, oligotrophic conditions. Because each species’ tolerance is well documented, researchers can calculate weighted indices from the composition of a diatom community, translating a census of glass-shelled cells into a quantitative statement about water quality. In this study, the authors computed thirteen separate diatom indices for each pond, spanning well-established European metrics for organic pollution, eutrophication and trophic status.

Among the indices deployed were the Specific Pollution Sensitivity Index, known as IPS, which reflects the proportion of pollution-sensitive taxa in a community, and the Eutrophication and Pollution Index, EPI-D, developed specifically for Italian waters. The team also calculated the Trophic Diatom Index, TDI, which tracks nutrient enrichment, and the SPEAR herbicides index, a trait-based measure that estimates the proportion of species at risk from herbicide exposure based on their physiological sensitivity, life cycle and generation time. Together, these metrics offered a multidimensional portrait of each pond’s ecological state, capturing pressures ranging from organic enrichment to agrochemical contamination.

The results painted a nuanced and somewhat counterintuitive picture. The Mediterranean ponds of Castelporziano generally recorded higher IPS and EPI-D values, both of which indicate better water quality and a community rich in pollution-sensitive species. This aligns with the site’s protected status: with public access restricted and surrounding habitat managed conservatively, the ponds experience relatively low direct human pressure. In contrast, the alpine ponds of Campo Imperatore, exposed to trampling, grazing and seasonal tourism, showed signs of greater ecological stress, consistent with the idea that even remote high-elevation systems are not immune to the cumulative effects of human land use.

Yet the alpine ponds told a second, equally important story. They displayed markedly lower TDI values than their Mediterranean counterparts, indicating lower trophic levels and less nutrient enrichment. Lower TDI values are generally a hallmark of cleaner, less eutrophic water, suggesting that while the Campo Imperatore ponds face disturbance from tourism and livestock, they are not necessarily drowning in nutrients. The alpine ponds also showed greater ecological variability between sites, reflecting the patchy and heterogeneous nature of the pressures they experience, and they harboured assemblages dominated by sensitive taxa, as evidenced by higher SPEAR herbicides index values, which point to limited herbicide contamination at these high elevations.

Read together, these findings illustrate why no single index can capture the full ecological condition of a temporary pond. The Mediterranean ponds scored better on pollution-sensitivity metrics, while the alpine ponds excelled on trophic and pesticide-related measures. Each site’s diatom communities were responding to a different constellation of stressors: direct physical disturbance and organic inputs from livestock on the one hand, and the distinct hydrochemical conditions of a Mediterranean lowland landscape on the other. The study’s thirteen-index approach, facilitated by modern computational tools that automate diatom metric calculation in the R statistical environment, demonstrates how a multi-metric framework can disentangle these overlapping signals in ways that any individual metric cannot.

The work carries particular significance in the context of European environmental policy. Under the Water Framework Directive, member states are required to monitor and restore the ecological status of freshwater bodies, yet small ponds have historically been underrepresented in national monitoring programmes, which tend to prioritise rivers and lakes. Temporary ponds fall through the cracks even more often, because their intermittent hydrology complicates conventional sampling. Studies like this one show that diatom-based assessment can be successfully applied to ephemeral systems, providing a scientifically defensible basis for including them in conservation planning. This matters because small waterbodies contribute disproportionately to regional freshwater biodiversity and deliver ecosystem services far exceeding their modest surface area.

The contrast between Castelporziano and Campo Imperatore also delivers a broader message about protection regimes. Restricting access and managing land conservatively, as at the presidential estate, appears to translate into measurably better water quality as read by sensitive diatom species. Meanwhile, the alpine ponds, despite sitting within a national park, still bear the ecological imprint of tourism and free-ranging livestock, suggesting that formal protection on paper does not always equal functional protection on the ground. The authors argue that targeted management, such as managing livestock access to pond margins and directing visitor traffic away from vulnerable pond networks, could meaningfully improve conditions at high-elevation sites without excluding people entirely.

As climate change reshapes precipitation patterns across the Mediterranean basin and mountain ranges alike, temporary ponds face a future of shortened and increasingly unpredictable hydroperiods, compounding the pressures documented in this study. Understanding their current ecological baseline is therefore not an academic exercise but a prerequisite for safeguarding them. By reading the glass-shelled testimony of diatoms, scientists have gained a sensitive, repeatable and relatively inexpensive way to track that baseline over time. The message encoded in these microscopic communities is clear: even the smallest and most fleeting bodies of water record in detail how we treat the landscapes around them, and they respond, both positively and negatively, to the choices we make about protection and land use.

Subject of Research: Diatom-based water quality assessment of Mediterranean and alpine temporary ponds in Central Italy

Article Title: Diatom indices reveal water quality patterns in Mediterranean and alpine temporary ponds

Article References: Taurozzi, D., & Scalici, M. (2026). Diatom indices reveal water quality patterns in Mediterranean and alpine temporary ponds. Environmental Monitoring and Assessment, 198(11), Article 1200. https://doi.org/10.1007/s10661-026-16086-3

Image Credits: AI Generated

DOI: 10.1007/s10661-026-16086-3

Keywords: diatoms, temporary ponds, water quality, bioindicators, Mediterranean ecosystems, alpine ponds, eutrophication, pollution sensitivity, conservation, Gran Sasso, Castelporziano, Environmental Monitoring and Assessment

The study, led by Hassiba Zediri of Badji Mokhtar Annaba University together with colleagues in Algeria and Italy, surveyed nine temporary ponds across the urban and peri-urban zone of the Annaba Plain between 2021 and 2024. Over four consecutive growing seasons the researchers recorded an astonishing 364 vascular plant taxa belonging to 214 genera and 72 families. For ponds sitting on the doorstep of a major industrial city, that level of floristic diversity is remarkable, and it confirms what conservationists have long suspected: temporary ponds act as refuges for rare and endemic plants even when surrounded by roads, fields and buildings.

The botanical signature of these ponds is unmistakably Mediterranean. Nearly 63 percent of the recorded flora belongs to the Mediterranean chorotype, the group of plants whose natural distribution is centred on the Mediterranean Basin. Equally telling is the life-form spectrum: 44.2 percent of the species are therophytes, annual plants that complete their entire life cycle within a single wet season, germinating as the ponds flood and setting seed before the water retreats. This boom-and-bust strategy is the classic adaptation to temporary ponds, where the timing and duration of flooding are as important as the water itself.

What makes the Annaba ponds genuinely special, however, is their conservation value. Six of the recorded species are protected under Algerian legislation, and five appear on the IUCN Red List. Among them is Rumex algeriensis, a dock classified as Critically Endangered, a plant found in the wild almost nowhere else. The presence of such species in waterbodies that are routinely trampled, grazed and drained underscores how much biodiversity can persist in small, unofficial wetlands that fall outside the usual network of protected areas.

To understand what structures this vegetation, the team measured 37 variables at each site, spanning soil chemistry, water quality, hydrology and physiography. These included organic matter, porosity, total carbon, total limestone, electrical conductivity, particle-size distribution of sand, silt and clay, pH, pond depth, surface area, perimeter, altitude, slope, exposure, and the intensity of grazing, fires and agricultural activity. Water samples were analysed for dissolved oxygen, temperature, total suspended solids, total phosphorus, nitrites and nitrates, both in situ and in the laboratory, following French and ISO standards.

A Principal Component Analysis of these variables revealed four distinct site clusters, and the factors that separated them were strikingly simple: salinity and electrical conductivity, pond surface area, and distance from the urban centre. In other words, the ponds sort themselves along two axes that ecologists care deeply about, how salty and how hydrologically variable the water is, and how strongly the city presses against each site. The first axis of the PCA alone accounted for 44.25 percent of the variance, with the second adding 27.48 percent, together explaining the bulk of the environmental variation across the nine ponds.

The researchers then went a step further, applying an Outlying Mean Index niche analysis to test whether plant species actually respond to these gradients rather than being distributed at random. The answer was a clear yes: species distribution was significantly driven by the environmental gradients, with a statistical significance of p below 0.05. The first axis, carrying 44.25 percent of the variance, reflected salinity and the hydrological regime, while the second axis, at 27.48 percent, opposed the low-altitude peri-urban ponds to the waterbodies of the urban plain. Each plant community, in effect, occupies a measurable niche defined by salt, water and geography.

From this analysis four plant community types emerged, each telling its own ecological story. A halophytic community thrives where salts accumulate, dominated by salt-tolerant species capable of coping with high electrical conductivity. A helo-hydrophytic community occupies the wetter zones, combining marsh plants with true aquatic species that depend on prolonged flooding. A psammophytic community colonises sandy substrates, its members adapted to loose, fast-draining soils, while a meso-xerophytic community inhabits the drier margins, tolerating moderate to pronounced drought stress. These four assemblages map neatly onto the environmental clusters, demonstrating that even small ponds contain sharply differentiated vegetation zones.

The darker side of the findings concerns what is filtering this diversity away. Urbanisation, agro-pastoral disturbance and salinisation emerged as the dominant ecological filters, selecting for stress-tolerant generalist species while eliminating the sensitive and endemic taxa that give Mediterranean wetlands their conservation value. Salinisation is a growing global threat to water resources in arid and semi-arid regions, and in coastal plains like Annaba it interacts with urban expansion and agricultural intensification to push plant communities toward a simplified, ruderal state. Rare species such as Rumex algeriensis sit precisely on the losing side of this filter, clinging to the few habitats where salinity and disturbance have not yet tipped the balance.

The authors argue that their results make the case for urgent conservation action in the Annaba Plain, where the remaining wetland habitats are shrinking under relentless pressure. Because the study identifies the specific gradients that control plant distribution, salinity, hydrological regime, pond size and urban proximity, it gives managers concrete levers: protect the hydroperiod of the ponds, curb salt inputs, limit grazing and fire around the most diverse sites, and prioritise the peri-urban low-altitude ponds that harbour the most distinctive communities. Temporary ponds are among the most threatened wetland ecosystems in the Mediterranean, yet this four-year census shows they can still shelter hundreds of species, including plants found nowhere else on Earth. Whether they continue to do so will depend on decisions taken now, in a plain where the city, the salt and the water are converging on the same fragile ground.

Subject of Research: Edaphic and hydrological factors structuring wetland plant communities in Mediterranean urban temporary ponds of the Annaba Plain, Algeria

Article Title: Edaphic and hydrological determinism of wetland vegetation in Mediterranean urban waterbodies: A case study from the Annaba Plain (Algeria)

Article References: Zediri, H., Belabed, A. I., Hamel, T., de Bélair, G., Aouadi, A., Kétif, A., & Domina, G. (2026). Edaphic and hydrological determinism of wetland vegetation in Mediterranean urban waterbodies: A case study from the Annaba Plain (Algeria). Plant Biosystems, 160(4), Article 215. https://doi.org/10.1007/s44473-026-00219-0

Image Credits: AI Generated

DOI: 10.1007/s44473-026-00219-0

Keywords: temporary ponds, wetland vegetation, Mediterranean flora, salinity, urbanisation, Annaba Plain, Algeria, plant communities, biodiversity conservation, Rumex algeriensis, hydrological regime, ecological filters