Search results for " alien"
showing 10 items of 89 documents
Pine stand density influences the regeneration of Acacia saligna (Labill.) H.L.Wendl. and native woody species in a mediterranean coastal pine planta…
2018
Mediterranean plantations are the most suitable areas to assess vegetation dynamics and competitive interactions between native and exotic woody species. Our research was carried out in a coastal pine plantation (Sicily) where renaturalization by native species (Pistacia lentiscus L. and Olea europaea var. sylvestris) and invasion by Acacia saligna (Labill.) H.L.Wendl. simultaneously occur. The regeneration pattern of woody species in the pine understory was evaluated in six experimental plots along a stand density gradient, from 200 to approximately 700 pines per hectare. Both pine stand density and regeneration by native species had a significant negative relationship with Acacia natural …
Solanum lanceolatum (Solanaceae) in Sicily: A new alien species for the European flora
2015
Solanum lanceolatum Cav. (Solanaceae) is a species native to Central America (Mexico, Belize, Guatemala and Panama), that has been found naturalized near Sutera and Porto Empedocle (Sicily). This is the first record in Italy and Europe.
Sobre alguns contrastos fonològics en l'entonació del català
2021
The main goal of this article is to provide evidence in favor of the phonological character of some intonational contrasts in Catalan. First, the article shows that tonal alignment differences with respect to metrically strong positions are crucial for the distinction between a yes-no question and a wh-question (cf. "¿Que l’ha llogada?" vs. "¿Qui l’ha llogada?") and between a command and a request ("¡Vine!" vs. "¡Vine!") in Central Catalan. Second, the article reports the major results from the application of the Categorical Perception Paradigm to a pitch height contrast in Majorcan Catalan (Vanrell 2006a). Experimental resuls show that a small variation in the pitch height of the pretonic …
Plant invasions on small Mediterranean islands. An overview
2016
Biological invasions have become one of the main drivers of habitat degradation and a leading cause of biodiversity loss in island ecosystems worldwide. The spread of invasive species poses a particular environmental threat on the islands of the Mediterranean Basin, which are hot spots of biodiversity and contain rare habitats and endemic species, especially on small islands, which are highly vulnerable to biodiversity loss. Following a recent survey, in this paper we aim to provide an overview of the present-day non-native vascular flora of small Mediterranean islands based on a sample of 37 islands located in the middle of the Mediterranean Sea, off the coast of Italy. By comparing the cu…
Tree invasions in Italian forests
2022
Many forest tree species have been moved outside their native range to provide goods and services elsewhere, but some of them have become invasive, causing negative impacts on biodiversity and human activities. The assessment and knowledge on the degree and scale to which forest ecosystems are invaded by non-native trees is of paramount importance for tailored policies and strategies aiming at forest conservation. By analyzing main databases and literature and applying a four-level scale of invasion (not currently invaded and with low invasibility; potentially invasible; moderately invaded; massively invaded), we assessed the current and potential occurrence of twenty-five invasive non-nati…
Parasites in sympatric populations of native and invasive freshwater bivalves
2021
An increasing threat to local, native freshwater mussels (Unionida)—an ecologically important but globally alarmingly declining group— is the invasion by exotic bivalves. The Enemy Release Hypothesis predicts that introduced species should benefit from enemy-mediated competition because they are less likely to be harmed by natural enemies, such as parasites, than their native competitors. We investigated within-site differences in parasitism between sympatric native (tot. five spp.) and invasive (tot. three spp.) bivalves in eight northern European waterbodies, which harboured totally 15 parasite taxa. In paired comparisons using within-site averages, the mean number of parasite species in …
The invasion history of Elodea canadensis and E. nuttallii (Hydrocharitaceae) in Italy from herbarium accessions, field records and historical litera…
2022
AbstractWe analysed the invasion history of two North American macrophytes (Elodea canadensis and E. nuttallii) in Italy, through an accurate census of all available herbarium and field records, dating between 1850 and 2019, and a rich literature collection describing the initial introduction and naturalisation phase that supports the results obtained by the occurrence records. Elodea canadensis arrived in Italy before 1866 and had two invasion phases, between the 1890s and 1920s and between the 1990s and 2000s; E. nuttallii, probably arrived in the 1970s, started invading in 2000 and the invasion is still ongoing. Botanical gardens and fish farming played a crucial role in dispersal and na…
Principi di spontaneizzazione in Sicilia di Talinum paniculatum (Talinaceae)
2017
Record of Talinum paniculatum (Talinaceae) naturalized in Sicily. – The record in the urban context of Palermo (Sicily) of Talinum paniculatum, species native to Tropical America and mainly cultivated for ornamental purposes, is reported. It is the first case of naturalization in the Island of a species of Talinaceae family introduced to Palermo in 1984 from Argentina and cultivated in the Botanical Garden collections.
ROLE OF SICILY AND CIRCUM-SICILIAN ISLANDS AS RECIPIENT AND DONOR AREA FOR ALIEN MARINE MACROPHYTES IN THE CENTRAL MEDITERRANEAN SEA
2017
The spread of alien species is an ongoing phenomenon which is widely recognized as a major threat to biodiversity at all levels. The particularly high rate of alien introductions to the Mediterranean Sea has been mainly fuelled by the opening of the Suez Canal, by shipping, aquaculture and by a rising trend in seawater temperature. As far as marine macrophytes are concerned, a total of 134 species have been listed as possible aliens in the Mediterranean Sea. Among the possible pathways of introduction, shipping is considered the dominant vector of unintentional species introduction in coastal marine systems worldwide. Traversing the Strait of Sicily, the chief passageway from south to north…
Uomini, altri animali, piante, razze e invasioni aliene: per un nuovo modello di sviluppo
2020
C'è una grande confusione nela valutare il ruolo che le piante aliene invasive giocano nel ridurre la biodiversità. Vengono chiariti alcuni concetti spesso oggetto di mistificazioni.