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Utricularia (bladderwort) trap contents have frequently been used to define its diet, but there is a scarcity of information on prey availability. Yet making comparisons between trap contents and outside communities could help define feeding strategies of these fascinating carnivorous plants. This study focuses on U. australis, the most common aquatic bladderwort in central Italy, with data of inside- and outside-trap communities from 23 sites. The feeding strategy of U. australis is highly dependent on prey availability and size; the prey has to be large enough to stimulate trap triggering, yet small enough to be taken up through the trap door unimpeded. In addition, the prey has to be moderately motile but not dispersive. The trap contents were generally a mixture of species taken up by active and spontaneous trap firing. Stimulation of a heavy epiphytic growth by Utricularia resulted in higher entrapment of epiphyte-grazing taxa resulting in a positive feedback loop. The comparative data here also suggest that prey digestion is a rapid enough process that keeps up with the seasonal succession of the outside community. The trapped community (or the diet) of U. australis seems to derive by the contribution of all these factors. [ABSTRACT FROM AUTHOR]

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 the field for biocontrol purposes. Indeed, the larvae having a herbivorous diet might consume a large amount of the invasive plant, contrarily to the adult phase which is focused exclusively on reproduction. Our results not only contribute to the knowledge of 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. [ABSTRACT FROM AUTHOR]

In this study, we analyzed the relationship between buried archaeological remains (masonries, pavements, and ancient ruins) and spontaneous vegetation growing above them. We carried out several vegetation surveys in the Domitian's Stadium at the archaeological site of the Palatine (Rome). Vegetation data were collected using the Braun-Blanquet approach and elaborated using statistical analyses (cluster analysis) to assess the similarity among surveys. Structural, chorological, and ecological features of the plant communities were analyzed. Results showed that the vegetation responds significantly to the presence of sub-emerging ancient remains. The plant bioindication of this phenomenon occurs through the following floristic-vegetation variations: phenological alterations in single individuals (reduction in height, displacement of flowering/fruiting period), increase of annual species and decrease of perennial ones, decrease of total plant coverage, reduction of maturity level of the vegetation which remains blocked at a pioneer evolutive stage. The presence of sub-surfacing ruins manifests itself through the dominant occurrence of xerophilous and not-nitrophilous species (e.g., Hypochaeris achyrophorus L., Aira elegantissima Schur, Trifolium scabrum L. ssp. scabrum, Trifolium stellatum L., Plantago lagopus L., Medicago minima (L.) L., and Catapodium rigidum (L.) C.E. Hubb. ex Dony ssp. rigidum) and in a rarefaction of more mesophilous and nitrophilous species (e.g., Plantago lanceolata L., Trifolium pratense L. ssp. pratense, Trifolium repens L. ssp. repens, and Poa trivialis L.). Therefore, the vegetation can be used as bioindicator for the detection of buried ruins, contributing in the archaeological prospection for a general, fast, and inexpensive interpretation of the underground. [ABSTRACT FROM AUTHOR]

The present study focused on the bryoflora of watercourses of the Tiber River basin watercourses (Central Italy). A total of 20 bryophyte species, which included 14 mosses and 6 liverworts, were collected at 32 river stations. Most species were recorded at stations of the watercourses' upper sections, which have rocky substrate and where there is cool and well oxygenated running water, with low trophic load. Only few species, such as Leptodictyum riparium, Cinclidotus fontinaloides and Riccia fluitans, were also found at stations of the middle and lower sections, which are characterized by slow-flowing, turbid, warm and eutrophic waters. Some species are widely distributed, among which Fontinalis antipyretica ssp. antipyretica and Platyhypnidium riparioides, while others are very rare, such as Cinclidotus aquaticus, Dialytrichia mucronata and R. fluitans. Some of the collected species are new regional records (Hygroamblystegium fluviatile, D. mucronata), regional confirmations of rare taxa in Italy (C.aquaticus) or confirmations of old regional reports (Hygroamblystegium tenax, C. fontinaloides, Aneura pinguis). [ABSTRACT FROM PUBLISHER]

Abstract: This study analyses the plant colonization of the stone embankments along the Tiber River (the Lungotevere) in relation to changes of lithotype (travertine, tuff, cement), inclination (80°, 60°, 45°), stone size, and exposure. The surveys of plant communities were carried out according to the phytosociological method and considering the variability of the ecological conditions. The vegetation data were analyzed using multivariate statistical analysis (cluster analysis) in order to highlight the affinity among the various groups of sampling areas. The ecological features of the vegetation, according to Ellenberg indicator values, were considered for the ecological interpretation. Results showed that many environmental factors interact in giving rise to a differential plant cover and species richness, but that some are more relevant than others, such as the lithotype nature, especially in relation to the differential stone porosity. Also, changes in inclination of the walls cause variations in plant colonization, especially in the case of travertine and less in the case of tuff, as a consequence of the differing porosity of these materials. The study also confirms the subordinate role of exposure with respect to other factors. [Copyright &y& Elsevier]

The aquatic plant communities of the Tiber River basin have been examined to evaluate their role as bioindicators of the water quality of the Italian peninsular rivers. The compatibility curves of phytocoenoses to water chemico-physical gradients show a correlation between the distribution pattern of the vegetation types and the water's chemico-physical features, such as different levels of water pollution. In particular, Fontinaletum antipyreticae, Ranunculo-Sietum, Elodeo-Potametum crispi and Nasturtietum officinalis develop in meso-eutrophic and fairly clean water, Potamogeton nodosus community and Ceratophylletum demersi in eutrophic water of medium quality, while Myriophylletum spicati and especially Potametum pectinati and algal communities with Entheromorpha flexuosa are found in hypertrophic water of poor quality. These phytocoenoses can be utilised as valid bioindicators of water quality. On the contrary, Callitrichetum stagnalis, Myriophylletum verticillati, Najadetum marinae and algal communities with Cladophora glomerata are not effective bioindicators, showing a wide and sometimes unclear synecology. [ABSTRACT FROM AUTHOR]

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. • Utricularia australis large benthic populations found at 4–6 m depth at the first time. • Surprising production of U. australis showy chasmogamous flowers at this depth. • Morphological differences among U. australis typical emerged and underwater flowers. • Underwater inflorescences had longer scapes and flowers smaller and longer styles. • They had thinner petals, nectar signalling less obvious and mucous-not grainy pollen. [ABSTRACT FROM AUTHOR]

Over the past four centuries, different lists of the flora of the Colosseum have been published (Jatrologismi sive medicae observationes quibus additus est in fine Plantarum Amphitheatralium Catalogus. Typis Dominici Marciani, Rome, p. 15; Enumeratio plantarum sponte nascentium in ruderibus Amphitheatri Flavii. Typis Pauli Salviucci et filii, Rome, p. 80; Flora of the Colosseum of Rome. London. p. 230; Florula del Colosseo. Atti Accademia Pontificia Nuovi Lincei 28, 20,7; 29, 33; 30, 8; 31, 13; Ann. Bot. (Roma) XXIII (fasc. 3) (1951) 393; Webbia 56(2) (2001) 321). The rich plant colonization (684 species, as the sum of the various lists) appears to be due to the great variety of habitats in the monument and to its state of abandonment. The comparison among the different floras allows a quantitative estimate of the following general changes to be determined: a gradual yet notable decrease of typical elements of mature dynamic stages; a constant decrease in species related to grazing and animal droppings, as well as in weeds from cultivated fields; and a constant increase of widely distributed and alien species, indicators of a different but ever stronger impact of man on the area. [Copyright &y& Elsevier]

• Ability in consuming alien Lemna minuta by native herbivorous larvae was tested. • Larvae of Cataclysta lemnata proved to consume and accept L. minuta as host plant. • Larvae effectively consume as much the native Lemna minor as the alien L. minuta. • Late-instar larvae were most efficient in consuming both Lemna species. • C. lemnata could help to contain the spread of the highly invasive alien L. minuta. Alien plant invasion is a serious threat for biodiversity conservation. Most theories on the mechanisms regulating the expansion of an alien species, agree that herbivory is one of the main factors affecting the success or failure of these species. One worrying example in Europe is the American duckweed Lemna minuta that, since its arrival in the 1940s, has become wide spread throughout many countries. This study focused on determining and quantifying the herbivorous nature of the larvae of the moth Cataclysta lemnata (native to Europe) with regards to L. minuta. On the premise that, if a native herbivore feeds on an alien plant species, it could help to contain its expansion. We tested the effectiveness of larvae at three different instars in consuming L. minuta under laboratory conditions. Laval preference for the alien L. minuta and the native L. minor was determined by quantifying the removal of monolayer mats of these two duckweeds. Firstly, we found that C. lemnata larvae was able to use L. minuta as a trophic resource and also to build protective cases. Moreover, they feed effectively, and seemingly without preference, on both the native and the alien species, contrary to the Enemy Release Hypothesis, which assumes that native consumers are better adapted to consume native species than alien ones. In addition, C. lemnata late-instar larvae were more efficient in Lemna consumption. This study suggests that where C. lemnata is a native herbivore the spread of L. minuta could be effectively contained. [ABSTRACT FROM AUTHOR]

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., (Copyright © 2020 Elsevier Ltd. All rights reserved.)