Stem-injection of herbicide for control of Ailanthus altissima (Mill.) Swingle: a practical source of power for drilling holes in stems

Ailanthus altissima is a well-known invasive tree in many parts of the world showing an outstanding ability to establish within woodlands and other less-disturbed habitats. Previous studies have reported that control of this species is very difficult because of its strong resprouting. Indeed, effective control can be achieved only by mechanical treatment followed by the application of a systemic herbicide. Operating drills or saws and other mechanical equipment require electric power supply which is not readily available in many invaded sites, notably shrubslands and woodlands. In two study sites, we evaluated control obtained by glyphosate through a stem-injection technique and compared two sources of power for the electric drill used. More than 90% of the glyphosate-treated trees in this study appeared to be dead just 1 month after treatments, and a car battery plus inverter was the most practical electrical source for drilling stems in the field

Un nuovo caso di spontaneizzazione incipiente: Lagunaria patersonia (Andrews) G. Don (Malvaceae) in Sicilia

In questa nota si riporta l’incipiente processo di naturalizzazione in Sicilia di Lagunaria patersonia (Andrews) G. Don, un albero australiano sempreverde di media grandezza appartenente alla famiglia delle Malvaceae

Seasonal effects on mortality rates and resprouting of stems treated with glyphosate in the invasive tree of heaven (Ailanthus altissima (Mill.) Swingle)

Tree of heaven (Ailanthus altissima) is regarded as invasive within urban and natural areas worldwide. Efficient methods to control it are significantly needed if we are to limit its well-known environmental and economic impacts. Up to now the use of herbicides has proven necessary since following mechanical damage, Ailanthus vigorously resprouts. However, the seasonal response of Ailanthus stems, treated with herbicides, has never been assessed. We compared the control efficacy recorded in autumn, winter and summer in an abandoned suburban citrus grove in Sicily, under Mediterranean-climate conditions. Glyphosate was injected within drill holes made in knee-high cut trees. Tree mortality and the resprouting ability of treated stems were significantly affected by the application timing and by diameter class of stems. Mortality was significantly lower in winter treatments within the smaller diameter class. Within the larger diameter class, only autumn treatments showed a notably higher mortality rate and a significantly lower growth of sprouts. Hence, autumn interventions are strongly recommended to effectively treat Ailanthus. Mortality was notably higher in the smaller diameter class. Our results confirm the importance of early intervention to control Ailanthus, also showing that the choice of the season is crucial to obtaining satisfactory control of its resprouting ability

Acacia cyclops A. Cunn. ex G. Don (Leguminosae) in Italy: first cases of naturalization

Linosa (Pelagie Islands, Strait of Sicily). A decade later, this alien plant should no longer be considered as a casual, since a very intensive process of self-sown regeneration has been observed in some plantations on Lampedusa, the major island of the same Archipelago. The available literature suggests the need for careful monitoring of the ongoing invasion process, as A. cyclops has already shown a very invasive behaviour elsewhere within Mediterranean-type biomes due to its ability to withstand high environmental stresses. As migrating birds are suspected to have played an important role in facilitating the arrival of A. cyclops, further propagules are likely to reach the islands in the future. We recommend that new plantations of A. cyclops should be forbidden, but that extant naturalized populations should be managed instead of eradicating them. In fact, the effect of Acacia plantations warrants investigation at different scales in order to assess their impact on local plant-diversity and ecological succession processes

Carbon storage of Mediterranean grasslands

Secondary grasslands are one of the most common vegetation types worldwide. In Europe, and in the Mediterranean basin, human activities have transformed many woodlands into secondary grasslands. Despite their recognized role in the global carbon cycle, very few data are available for estimating the biomass of Mediterranean grasslands. We developed linear regression models in order to predict the biomass of two native Mediterranean grasses (Ampelodesmos mauritanicus and Hyparrhenia hirta) and an invasive alien grass (Pennisetum setaceum). Ampelodesmos mauritanicus is very common throughout the Mediterranean basin, mostly on north-facing slopes, H. hirta characterizes thermo-xeric grasslands, while P. setaceum is an alien species that is rapidly spreading along coastal areas. The measured morphometric attributes of individual plants as potential predictors were considered. The validation results corroborate the ability of the established models to predict above ground and total biomass of A. mauritanicus and P. setaceum. We also evaluated the total biomass per hectare for each species. The highest biomass per hectare was found for A. mauritanicus, whereas biomass was higher for H. hirta than for P. setaceum. The replacement of H. hirta by P. setaceum may reduce the total carbon storage in the ecosystem; however, P. setaceum allocates more resources to the roots, thus increasing the more stable and durable pool of carbon in grasslands

Primi casi di naturalizzazione del noce nero (Juglans nigra L.) (Juglandaceae) in Sicilia

Il presente studio riporta i primi casi di naturalizzazione del noce nero in Sicilia. Il possibile ruolo giocato dagli animali disseminatori e dalle condizioni climatiche locali sono stati discussi

Nicodemia madagascariensis (Lam.) R. Parker (Family Scrophulariaceae), a casual alien plant new to Italy

In this note the authors report the first case of naturalization of the Malagasy smoke bush within Italian territory. Along with a description of the abiotic and biotic characteristics of the invaded site, the current demographic and dynamic trends of the detected population by means of growth-ring analysis was also assessed. Moreover, an overview on the history of its introduction in Europe is provided, underlining the key role played by the Mediterranean cities with respect to the acclimatization and spread of alien tropical and subtropical plants. Due to its low frequency under cultivation, the Malagasy smoke bush should not behave as an invader in the future; on the other hand, its ability to cover and smother neighbouring trees in very short times, make its spread within the whole Mediterranean area worth regular monitoring

Carbon storage of Mediterranean grasslands

Secondary grasslands are one of the most common vegetation types worldwide. In Europe, and in the Mediterranean basin, human activities have transformed many woodlands into secondary grasslands. Despite their recognized role in the global carbon cycle, very few data are available for estimating the biomass of Mediterranean grasslands. We developed linear regression models in order to predict the biomass of two native Mediterranean grasses (Ampelodesmos mauritanicus and Hyparrhenia hirta) and an invasive alien grass (Pennisetum setaceum). Ampelodesmos mauritanicus is very common throughout the Mediterranean basin, mostly on north-facing slopes, H. hirta characterizes thermo-xeric grasslands, while P. setaceum is an alien species that is rapidly spreading along coastal areas. The measured morphometric attributes of individual plants as potential predictors were considered. The validation results corroborate the ability of the established models to predict above ground and total biomass of A. mauritanicus and P. setaceum. We also evaluated the total biomass per hectare for each species. The highest biomass per hectare was found for A. mauritanicus, whereas biomass was higher for H. hirta than for P. setaceum. The replacement of H. hirta by P. setaceum may reduce the total carbon storage in the ecosystem; however, P. setaceum allocates more resources to the roots, thus increasing the more stable and durable pool of carbon in grasslands

The recent spread of the invasive woody alien plant Melia azedarach L. (Meliaceae) in Sicily

This paper aims at reporting the ongoing process of naturalization of Melia azedarach L. in Sicily. In fact, over half a century after the first detection of spontaneous self-sown seedlings, an abrupt increase of naturalization cases has been recorded by the authors during the last twenty years. More in detail, M. azedarach successfully colonized many suburban lowland areas along the coasts of the island which are characterised by thermo-Mediterranean bioclimate. According to both field and literature data, a gradual spread of M. azedarach in the island can be expected, although it is not possible to predict the speed with which this will occur. Historical information on its introduction at global and local scales and on the traditional use of its seeds is provided, too

ANREDERA CORDIFOLIA (TEN.) STEENIS (Basellaceae): STATUS IN ITALIA E SUA ESPANSIONE IN SICILIA OCCIDENTALE

In questa nota si fornisce un quadro aggiornato sui casi di naturalizzazione di Anredera cordifolia in Sicilia e sul suo status invasivo a livello nazionale. Questa xenofita viene inoltre segnalata per la prima volta per le province di Agrigento, Palermo e Trapani