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The free-floating aquatic plant Utricularia australis has typically subsurface shoots and subaerial showy inflorescences. To find it growing with large populations among benthic Chara stands at 4–6 m depth in two Central Italian lakes, is a phenomenon that was never previously reported. Production of showy chasmogamous flowers at this depth makes such finding yet increasingly intriguing. Here we make quantitative-qualitative comparisons of morphological characters among subaerial and underwater flowers taken from diverse sites in Central Italy. Environmental data were used to delineate differences between superficial and underwater habitats where flowering U. australis populations were found, and to help explain these extraordinary findings. Although similar, the subaerial and underwater flowers did show some differences, the most important being the length of the floral scape. Underwater scapes were around three times longer than those emerged. This might be a typical phototropic-response or a failed attempt to get flowers above water surface for allowing entomophilous pollination, or a redundant morpho-physiological trait as a result of a recent ecological move. Underwater flowers were generally smaller, but they did have longer styles, nectar signalling was less obvious, thinner petals, mucous-coated pollen (subaerial pollen is dry and grainy). Both types of flower were sterile, producing abortive fruits. Possibility of underwater ecological conditions causing stress-induced flowering is also proposed. A lack of water movement is an important ecological requirement for U. australis growth and could explain why large populations have been found in deep water far from its typical habitat.

Phylogenetic relationships are important to explain clade evolutionary history, but they are frequently difficult to identify. Myrtaceae family has been shown as potentially good case - study to resolve several phylogenetic questions regarding its family history and evolution. The Myrtaceae (Myrtales order) contains over 5500 species within 144 genera, distributed predominantly in Southern Hemisphere. Several Myrtaceae taxa are known for their economic importance and notable representation in the humid pleotropic forests. The family includes two subfamilies, Psiloxiloideae and Myrtoideae. Interestingly, the Myrtoideae subfamily has a marked disparity in taxa number among its tribes that it has never been explained. Moreover, it includes species with different fruit type (fleshy, dry fruits) and this peculiarity has been previously considered to explain the subfamily diversification, but to no avail. A more highly comprehensive matrix of the BKMMST clade within Myrtoideae was generated and newly analysed. The results showed that considering mainly certain character state (molecular, fruit type, habitus) has been possible provided a new interpretation of family evolution. Fruit types and habitus traits were mapped and different Myrtoideae tribes were spatially and temporally compared. The conclusions represent an added important step to explain the phylogenetic relationships of this complicated family and evaluate a new evolutionary prospective.

Stone surfaces can be subjected to biodeterioration due to the growth of photosynthetic organisms where favourable conditions of the environment and specific substrate materials are present. In this work, we investigated through genetic analysis and ecological observations the widely occurring reddish patinas, which are spread on stones in particular environmental conditions. We collected patina occurrence and environmental data at sites in the Lazio region covering an altitude range of 0 to 650 m asl and distances up to 70 km from the coast to define the ecological range. The results of blast analysis of DNA sequences confirmed a dominant presence of the filamentous terrestrial green alga Trentepohlia umbrina (Kützing) Bornet in all sites, sometimes mixed to cyanobacteria of the genus Gloeocapsa. In one site we identified T. aurea (L.) C. Martius, which occurs in different micro-environmental conditions. Originally the distribution of Trentepohliales was given as pan-tropical, but some temperate taxa have now been identified, such as T. umbrina. Preferred environmental conditions of this species were a relatively low humidity, vertical (or near vertical) surfaces, temporal diurnal shade-exposure and a mainly northern aspect. Coastal areas were more favourable for its growth, as the patinas were much more developed compared to sites further inland. Cement materials and mortars resulted particularly bioreceptive, possibly due to their soluble salt content, but tuffs and marble were also colonised under favourable conditions. The findings here suggest that the ecological preference of this species is wider than previously thought and urges the need for detailed studies on its biodeteriogenic nature.

The relationship between ostracod and macrophyte communities has been seldom studied, especially in urban parks. This is the first study of its kind in the area of Rome, and in particular in the Appia Antica Regional Park (Rome, Italy). The survey has considered different water bodies: springs, channels, ditches and a pond. Chemical and physical parameters were measured in 13 sites during the 4 different seasons together with granulometry analyses. The ostracod assemblage includes 11 species whereas the macrophyte community is formed by 17 species. Their relationship with the measured abiotic parameters has been studied through several statistical analyses: cluster analysis, non-metric multidimensional scaling and canonical correspondence analysis. The results clearly separate the investigated area in one sector where COD and phosphates are the driving factors and another sector where nitrogen substances, pH and conductivity are the main influencing factors. To better understand the ostracod-macrophyte interaction, Spearman rank-order correlation analysis was performed, confirming such a link. Although the macrophyte community is clearly affected by human pressure, the relationship with the ostracod assemblages seems well established and identified by exclusive pairs or groups of species. Among them, the Cypria lacustris-Lemna minuta duo is of considerable importance, being L. minuta an exotic species, known as an invasive weed in some areas of Europe and spread in Italy only recently. The fact that the 13 sites were characterized by different public access regulation has been partially mirrored by both ostracod and macrophyte distribution since the majority of the sites characterised by the highest diversity are those with restricted access. In general, notwithstanding the anthropic pressure, the occurrence of different kinds of water bodies has allowed the development of ostracod and macrophyte associations, which are rarely represented in an urban park.

The main aim of this study was to improve the knowledge about the concordance among macrophytes and macroinvertebrates to provide complementary information and facilitate the procedures for quality assessment of river ecosystems. Macrophytes and macroinvertebrates were collected in 11 sampling sites along a central Apennine calcareous river in October 2008 and June 2009. The concordance between the two biomonitoring groups was tested according to several environmental parameters. The comparison of the data matrix similarities by the Mantel test showed differences in the assemblage of macrophytes and macroinvertebrates along the river since correlation values were 0.04, p>0.05 in October 2008 and 0.39, p>0.05 in June 2009. The study revealed a lack of concordance between the two groups emphasizing the information provided by macrophytes and macroinvertebrates does not overlap in terms of response to environmental parameters. Indeed, the two different biological groups resulted useful descriptors of different parameters. Together, they could represent a complementary tool to reflect the river environmental quality.

In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions. Furthermore, three new combinations are proposed. Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1.

Invasive alien plants are a major threat to biodiversity and they contribute to the unfavourable conservation status of habitats of interest to the European Community. In order to favour implementation of European Union Regulation no. 1143/2014 on invasive alien species, the Italian Society of Vegetation Science carried out a large survey led by a task force of 49 contributors with expertise in vegetation across all the Italian administrative regions. The survey summed up the knowledge on impact mechanisms of invasive alien plants in Italy and their outcomes on plant communities and the EU habitats of Community Interest, in accordance with Directive no. 92/43/EEC. The survey covered 241 alien plant species reported as having deleterious ecological impacts. The data collected illustrate the current state of the art, highlight the main gaps in knowledge, and suggest topics to be further investigated. In particular, the survey underlined competition as being the main mechanism of ecological impact on plant communities and Natura 2000 habitats. Of the 241 species, only Ailanthus altissima was found to exert an ecological impact on plant communities and Natura 2000 habitats in all Italian regions; while a further 20 species impact up to ten out of the 20 Italian administrative regions. Our data indicate that 84 out of 132 Natura 2000 Habitats (64%) are subjected to some degree of impact by invasive alien plants. Freshwater habitats and natural and semi-natural grassland formations were impacted by the highest number of alien species, followed by coastal sand dunes and inland dunes, and forests. Although not exhaustive, this research is the first example of nationwide evaluation of the ecological impacts of invasive alien plants on plant communities and Natura 2000 Habitats.

This study provides a first step toward the knowledge of the alien-dominated and co-dominated plant communities present in Italy. The first ever checklist of the alien phytocoenoses described or reported in literature for the Italian territory has been compiled, produced by data-mining in national and local thematic literature. The resulting vegetation-type draft-list has been checked in the light of the most recent syntaxonomic documentation and updated with regards to syntaxonomy and nomenclature, with special reference to the frame proposed in the Italian Vegetation Prodrome. The list includes 27 vascular and one bryophyte vegetation classes, hosting 194 low rank alien-dominated syntaxa. The different vegetation types detected for each syntaxonomic class and macro-vegetation group, defined by physiognomical and ecological attributes, are discussed.

The Asian tiger mosquito, Aedes albopictus, one of the world's worst invasive animal species and competent vector of many arboviruses, poses a serious threat to human health. An effective and environmentally friendly control strategy is required to mitigate the negative impacts of this pest. The aquatic carnivorous plants of the Utricularia genus, known as bladderworts, feed on invertebrates using their modified leaves as traps (bladders) and could be considered for biological control. The southern bladderwort, U. australis, was used in a no-choice experiment to test its predation ability against Ae. albopictus larvae. Larvae were divided in two size groups: 1st-2nd and 3rd-4th larval instars. Twenty Ae. albopictus larvae were placed inside 1 l plastic cups with a 30 cm long segment of the plant and left for a 7-day period. Twelve segments of U. australis were used, six for each larval size group, counting the number of bladders of each segment at the beginning of the experiment. The 7-day process was repeated five times for each segment/cup over a two-month period. The number of captured larvae and emerged adults was recorded daily. A total of 84 captured larvae were chosen to measure larval length, percentage of larval body trapped within the bladder, bladder perimeter and bladder area, in order to evaluate the ability of the bladders in capturing larvae, by complete or partial suction of the body, depending on the relative sizes of larvae and bladders. Results indicated that U. australis is an effective predator of Ae. albopictus larvae, with a higher efficiency against the 1st-2nd instar group (72%) compared to the 3rd-4th group (39%). The number of captured larvae depended on the number of bladders on each segment and instar group. The percentage of trapped larval body depended on the relationship between bladder size and larval length. Although the bladders effectively captured small larvae by complete suction of the body, they also killed 3rd-4th instar larvae by trapping a small portion of the body within the lumen. The plant segments continuously captured mosquito larvae, with an efficiency that did not decrease during the 2-month period. The use of U. australis as a biocontrol agent against Ae. albopictus larvae could be favoured by its ecological plasticity, broad distribution, its ability to thrive in small containers and the good overlap of the two species regarding phenology and habitat preferences.

Urban rivers may perform important ecological roles and provide many ecosystem services, especially in urban contexts. Considering this, River Contracts were officially introduced in 2000, during the Second Forum of the World Water Council, as participative agreements aimed at managing the complexity of fluvial ecosystems. Collecting data on fluvial and riparian biodiversity, establishing ecological relationships among biological components, and evaluating their resistance and resilience to anthropic impacts are needed to assess the ecological sustainability of the anthropic actions. Here, we provide a review of literature and regulation on River Contracts, and a methodological contribution to the evaluation of different environmental components, their ecological connections, and the role of anthropic impacts. To address the aim, we performed a critical analysis of the existing data on the Tiber River close to Rome. We used the information to identify the actions that should be included in the Tiber River Contract to improve its natural value and its potential ecosystem services. Several areas emerged where information was lacking such as the human impact on these ecosystems. Data highlight the disappearance of rare Mediterranean species and of those linked to wetland habitats, as well as an increase in alien species and species typical of disturbed areas. Further research on biodiversity and management is required to support nature conservation.

Life cycle of the aquatic moth Cataclysta lemnata (Lepidoptera: Crambidae) was studied in laboratory conditions to obtain a basic biological knowledge useful for predicting the possible success of the herbivorous larvae of this insect as potential control agents in limiting the spread of the invasive American duckweed Lemna minuta (Alismatales: Araceae) in Italy. The multivoltinism of C. lemnata, as well as the high overall emergence from the pupal stage (85%), the high success in mating among the formed couples (>90%), and the high number of larvae born from each egg laying (on average 310 individuals), suggest that the insect can be successfully bred in the laboratory for the purposes of an augmentative biological control. Under experimental conditions, larvae developed in 23 days (through six larval instars, distinguishable by cephalic capsule dimensions) and pupae in 10, with no difference in duration between females and males. The larval phase resulted longer than the adult one (23 vs 10 days), therefore it can be considered the most suitable stage for releasing the insect in field for biocontrol purposes. Indeed, the larvae having a herbivorous diet might consume large amount of the invasive plant, contrarily to the adult phase which is focused exclusively on reproduction. The results emerged not only allow to contribute to the knowledge on aquatic lepidoptera that are scarcely known, but also support the effectiveness of a possible protocol for an augmentative biological control of the invasive alien duckweed L. minuta.

The structural characteristics of diatom cell walls (frustules) has led to their widespread use in diverse biotechnological applications, some of which can be further improved by surface chemical modification (functionalization). The use of coating agents can significantly increase surface binding capacity for target compounds. Frustules of the diatom Staurosirella pinnata used here were a by-product after applying a cascade-extraction process (for other products) to mass cultures. The protocol for the cleaning and functionalization of raw frustules using 3-Mercaptopropyl-trimethoxysilane and 3-Aminopropyl-trimethoxysilane was optimized and reported. Functionalization efficacy was observed using Electron Microscopy, Energy Dispersive X-ray Spectroscopy and Fourier-Transform Infrared Spectroscopy. Optimally functionalized frustules were evaluated for nickel removal from aqueous solutions. Incubations of 10 min, using 1 g/L of frustules, gave almost complete Ni removal with functionalized frustules compared to 3% removal by raw frustules. The proposed protocol represents a reproducible and efficient alternative for Ni removal from contaminated water.

– In this note we report the first direct evidence for Europe of coypus (Myocastor coypus) feeding on freshwater algae. Coypus fed on green algae of the genus Spirogyra (Zygnematophyceae) in a mediterranean coastal wetland of central Italy (Torre Flavia) where Spirogyra represents the most spread filamentous macroalgal stands. By analyzing Spirogyra stands, we also detected the presence of microalgae which, in turn, have been indirectly ingested by coypus: Ulnaria capitata, Navicula sp., Nitzschia sp. (Bacillariophyceae), Netrium digitus (Zygnematophyceae), and Phacus sp. (Euglenophyceae). Other taxa of green macroalgae, such as Cladophora glomerata and Ulva intestinalis (Ulvophyceae), were commonly recorded in the same area, however there is no evidence that they were consumed by coypus.

Phytoremediation potential of duckweeds (Lemna minuta, Lemna minor) to remove nutrients from simulated wastewater was analyzed. In two separate experiments, the two species were grown for 28days in waters enriched with nitrate and phosphate to simulate nutrient concentrations of domestic wastewater. Water physicalandchemical measurements (temperature, pH, conductivity, oxygen) and plant physiological and biochemical analysis (biomass, relative growth rate–RGR, nutrient and chlorophyll contents, peroxidative damage, bioconcentration factor–BCF) were made to test and compare the phytoremediation capacity of the two Lemna species. L. minuta biomass increased almost tenfold during the time-course of the treatment resulting in a doubling of the mat thickness and a RGR of 0.083 ± 0.001g/gday. Maximum frond content of phosphate was reached by day 21 (increase over 165%) and nitrate by day 7 (10%). According to the BCF results (BCF > 1000), L. minuta was a hyperaccumulator for both nutrients. On the other hand, L. minor biomass and mat thickness decreased continuously during incubation (RGR = − 0.039 ± 0.004g/gday). In L. minor fronds, phosphate content increased until day 14, after which there was a decrease until the end of the incubation. Frond nitrate content significantly decreased by day 7, but then remained relatively constant until the end of the experiment. L. minor proved to be hyperaccumulator for phosphates, but not for nitrates. Results indicated L. minuta has a greater potential than L. minor to remove both nutrients by bioaccumulation, especially phosphates, demonstrated also by better physiological and biochemical responses. However, during the incubation, the chlorophyll content of L. minuta mat did continuously decrease and peroxidative damage had increased until day 14, indicating that the system was under some kind of stress. Strategies to avoid this stress were discussed.

This paper reviews the current state-of-the-art, limitations, critical issues, and new directions in freshwater plant ecotoxicology. We selected peer-reviewed studies using relevant databases and for each (1) publication year, (2) test plant species, (3) reference plant group (microalgae, macroalgae, bryophytes, pteridophytes, flowering plants), (4) toxicant tested (heavy metal, pharmaceutical product, hydrocarbon, pesticide, surfactant, plastic), (5) experiment site (laboratory, field), and (6) toxicant exposure duration. Although aquatic plant organisms play a key role in the functioning of freshwater ecosystems, mainly linked to their primary productivity, their use as biological models in ecotoxicological tests was limited if compared to animals. Also, toxicant effects on freshwater plants were scarcely investigated and limited to studies on microalgae (80%), or only to a certain number of recurrent species (Pseudokirchneriella subcapitata, Chlorella vulgaris, Lemna minor, Myriophyllum spicatum). The most widely tested toxicants on plants were heavy metals (74%), followed by pharmaceutical products and hydrocarbons (7%), while the most commonly utilized endpoints in tests were plant growth inhibition, variations in dry or fresh weight, morpho-structural alterations, chlorosis, and/or necrosis. The main critical issues emerged from plant-based ecotoxicological tests were the narrow range of species and endpoints considered, the lack of environmental relevance, the excessively short exposure times, and the culture media potentially reacting with toxicants. Proposals to overcome these issues are discussed. Supplementary Information The online version of this article (10.1007/s11356-020-11496-3) contains supplementary material, which is available to authorized users.

The American duckweed Lemna minuta is invasive in freshwater habitats across much of Europe, often causing serious ecological impacts. To date, few studies have addressed how to halt its expansion. However, encouraging empirical evidence of L. minuta control by the aquatic herbivorous larvae of the insect Cataclysta lemnata is emerging. To better understand the biocontrol capacity of C. lemnata, information on overlap in the phenology and the growth conditions in nature of both species is fundamental. In this study, L. minuta and C. lemnata populations were analyzed in the field to define (i) their phenological features, (ii) the main environmental characteristics where the two species occur, and (iii) any overlap or difference in phenology and ecological requirements. The seasonal occurrence of the two species and environmental data were collected from 31 wetlands in central Italy. The two species showed a large phenological overlap and ecological similarities. Populations of L. minuta and C. lemnata were found all year long, although abundances were greater in spring and summer. Both species preferred waters that were shallow, circumneutral, with moderately high conductivity and trophic level and with low dissolved oxygen. The phenology and ecology of the two species were shown to be compatible, suggesting the insect could be released in natural sites invaded by the alien L. minuta where could act as potential biocontrol agent of it.

Since effects of alien invasive free-floating plants can be relevant in aquatic ecosystems, we investigated the non-native Lemna minuta impact on four aquatic animal groups: Hydra vulgaris (Coelenterates), Asellus aquaticus (Arthropods), Gambusia affinis (Fish), Bufo bufo tadpoles (Amphibians). An indoor experiment was conducted keeping animals in water held in tanks with L. minuta mats of 0.5 (WI1), 1.5cm thick (WI2) and without mats (WOU). Water parameters (DO, DO%, pH) and animal responses (survival rate, vitality) were measured every 48 h (0–288 h). Treatments with mats showed significant impacts on animals which were more severe with increasing mat thickness. Strong decreasing of oxygen and pH associated with mat occurrence had a large impact on animals. In WI2 all individuals died within 144 h (H. vulgaris, B. bufo within 96h), while in WI1 there was a higher survival rate and vitality (excluding B. bufo died within 96 h) and in WOU no deaths. This evidence suggests L. minuta thick mats (1.5cm) could have a high impact on animal biodiversity, especially reducing oxygenation level in aquatic ecosystem.

Utricularia australis is an aquatic rootless carnivorous plant that takes up nutrients through shoots or from trapped prey digested in its bladders. As the information on the ecology of this species is scarce, the main environmental factors which favour or limit its growth were analysed. Habitat characterization was carried out on 23 aquatic sites in Central Italy where U. australis occurred. Diverse water chemical and physical factors and aquatic plant dominants were sampled and compared to Utricularia coverage. Species response curves with respect to each analysed ecological factor were elaborated. Despite the large environmental variation among sites, U. australis did show some ecological preferences. Optimal growth of Utricularia was associated with sunny sites (~ 1500µmol photon m−2s−1) and shallow waters (< 20cm) that were warm (~ 26°C), alkaline (pH 8.3 median value), with moderate-high conductivity (700µScm−1) and with low aquatic inorganic phosphorus (< 10µgL−1) but higher nitrogen (800–1600µgL−1). Dissolved and particulate organic nutrients (mainly phosphorus) were highly important in determining U. australis ecology and its distribution. The knowing of theecological preferences ofU. australis, a plant that is becoming increasingly rare in Central Italy, could be very useful to identify and protect its habitats or to identify new potential sites and to avoid further population losses.