Search results for " macrophyte"
showing 10 items of 16 documents
Macrophyte assessment in European lakes: Diverse approaches but convergent views of ‘good’ ecological status
2018
Graphical abstract
Differences in the growth cycle ofRuppia cirrhosa(Petagna) Grande in a Mediterranean shallow system
2014
Ruppia cirrhosa growth cycle was analysed in a southern Mediterranean shallow system throughout 1 year. We examined the temporal variation in R. cirrhosa cover percentage, shoot density, biomass, leaf length, no. flowers m-2 and no. fruits m-2 in two groups of pond characterized by differences in some environmental parameters. Ponds were comparable for salinity and temperature but they differed for other environmental parameters such as water depth, level of suspended organic matter and chlorophyll a (CHL a). Biological parameter values were higher in B ponds, characterized by lower values of water depth, suspended organic matter and CHL a. A seasonal trend for all considered biological par…
Diploid Ruppia cirrhosa populations from a southern Mediterranean shallow system
2016
Abstract This paper focuses on the morphology and karyology of representative Ruppia populations from a southern Mediterranean shallow system. The cosmopolitan genus Ruppia L. generally inhabits shallow waters such as coastal lagoons and brackish habitats. Ruppia species are characterised by a simplified morphology and high intraspecific phenotypic plasticity. The chromosome number of Sicilian Ruppia populations is reported here for the first time. The analysed populations showed morphological and reproductive characters of Ruppia cirrhosa (Petagna) Grande but a diploid cytotype (2n = 20). A low fruit production was also observed, suggesting that vegetative reproduction is the main reproduc…
Chara hispida beds as a sink of nitrogen: Evidence from growth, nitrogen uptake and decomposition
2007
8 pages, and tables stadistics, and figures.
Citizen science projects for monitoring alien macrophytes
2016
To understand the invasive potential and the spread dynamics of an alien species, any newly colonized area needs to be quickly detected. Therefore, regular monitoring programs and public awareness campaigns are essential. Since intensive monitoring activities involving scientists are expensive, the occurrence and spread of marine species could remain undetected or could be detected only years after the initial colonization. Citizen Science initiatives, a potential solution to this problem providing supplemental information that would otherwise be lost, are able to involve different groups of volunteers: students, tourists, divers, underwater photographers, amateurs and fishermen. Volunteers…
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…
Isoëtes sabatina (Isoëtaceae, Lycopodiopsida). Taxonomic distinctness and preliminary ecological insights
2021
1) Isoëtes sabatina is the rarest aquatic quillwort in Europe. Although recently found (2013) in Lake Bracciano (central Italy), the species is just one step away from extinction with an estimated population not exceeding 400 individuals and a spatial range of a few hundred square metres. 2) Lake Bracciano is a deep, oligo-mesotrophic Mediterranean volcanic lake that has been subjected to human activities. From January to October 2017, the lake experienced a dramatic water level decrease (up to −1.50 m), which significantly affected the littoral zone and the habitat of I. sabatina. 3) To improve the chances of survival of I. sabatina, the first eco-taxonomic investigation on this species wa…
Alien macrophytes in the Mediterranean Sea: an overview
2019
The Mediterranean Sea, one of the most complex marine ecosystems, is inhabited by a rich and diverse biota which is disproportionate to its dimensions. Such high species richness makes the Mediterranean Sea a true hotspot of biodiversity. However, the Mediterranean Sea is amongst the most impacted regional sea areas, due to increasing levels of threats, mainly driven by human activities such as climate change and the introduction of non-indigenous species (NIS, i.e. organisms introduced outside of their natural, past or present, range and outside of their natural dispersal potential). NIS may in time become invasive (i.e. invasive alien species (IAS)) with severe impacts on biodiversity and…
Citizen and scientists work together to monitor marine alien macrophytes
2018
The introduction of non-indigenous species (NIS) is an ongoing phenomenon which has been pointed out as a major threat to biodiversity at different levels (Wallentinus, Nyberg 2007, Katsanevakis et al. 2014, Vergés et al. 2016). NIS may in time become invasive (Invasive Alien Species “IAS”) and may cause biodiversity loss and ecosystem service changes (Brunel et al. 2013, Giakoumi 2014, Vergés et al. 2016). The Mediterranean Sea is an important hotspot for marine NIS (ca. 1,000 such species recorded to date, Zenetos et al. 2012, Galil et al. 2015, Verlaque et al. 2015). To reduce the risk of future IAS introduction and to better understand their invasive po- tential and spread dynamics, mon…
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…