89 research outputs found
MACROINVERTEBRATES OF ITALIAN MOUNTAIN LAKES: A REVIEW
The paper summarizes the state of knowledge and the evolution of the researches on benthic macroinvertebrates ofItalian mountain lakes, and identifies key aspects that need to be further explored. Mountain lakes have been investigatedsince the end of the XIX century. In the beginning, studies focused mainly on their geography, geology, geomorphologyand hydrology. Only lately, interests arise on their hydro-chemistry and biology, in relation to water acidification and, inrare cases, to eutrophication. In particular, in the 1920s, the studies dealt mainly on lake basins morphology and theirgenesis. Later, researches were driven mainly by the growing need of hydroelectric power plants, shifting the attention ontheir hydrological and geological aspects. Nonetheless, more detailed limno-biological studies began in confined areas.During the 1960s, attention was redirected to the alpine environment in terms of environmental awareness, for the creationof parks, and to analyse the alteration of water quality caused by the deposition of transported pollutants from thelowlands. This created the opportunity to combine observations on both the hydro-chemical and biological aspects, toreach a synoptic view of these environments. It is only in the mid-1990s that ISI journals came to power and, striving forhigher visibility, strongly promoted the production of papers. In this decade, the application of paleo-limnology, thecreation of a long term ecological research network, the never abandoned idea of implementing best practice managementfor freshwaters conservation purposes, and the growing attention on the global climatic change gave new impulse to thestudies on mountain lakes. Since the 2000s, biodiversity preservation, biological recovery, environmental key-drivers(mainly nitrogen increase) have become the new focus of the current research activities
Alien species in Italian freshwater ecosystems: a macroecological assessment of invasion drivers
Progetto pilota per lo studio multidisciplinare ed integrato su un sottobacino del Lago Maggiore
No abstract availableComposizione granulometrica del sedimento; campionament
Recenti sviluppi nella classificazione ecologica dei laghi tramite i macroinvertebrati
Quantile regression analysis was here used to explain different metrics of diversity of macroinvertebrate community in response to twenty-one variables representing chemical, physical and morphological characteristics of the environments. Nine lakes located in two Italian regions (Piedmont and Sardinia) were analyzed. Using quantile regression to evaluate limiting responses, only two variables, sampling depth and oxygen percent saturation (oxygen content), resulted the ones that best explained all the analyzed metrics of diversity of the macroinvertebrate community. Depth and oxygen were then used to suggest models describing the various metrics of potential community diversity. These models can help the environmental agencies responsible for monitoring at the national level in distinguishing entire lakes or part of them with high biodiversity from those in altered conditions and then address remediation efforts towards the water bodies with the most critical conditions. Such approach could also be used to optimize the sampling procedures for the application of the Benthic Quality Index for lakes currently adopted at national level
Protocollo di campionamento ed analisi granulometrica di sedimenti lacustri
No abstract availableI sedimenti, la loro origine, la loro distribuzione, e l\u27analisi della loro tessitura di un lago svolgono un ruolo importante per i macroinvertebrati in quanto forniscono utili indicazioni sull\u27assenza di determinate famiglie quando troppo grossolani e sulla presenza di altre quando fini. Il documento vuole fornire agli operatori in campo ambientale una guida al loro campionamento e all\u27analisi dimensionale a supporto delle analisi biologiche condotte in parallelo ad esse. Dal confronto analisi biologica-analisi tessiturale risulter? pi? facile argomentare la distribuzione in specie e la diversa composizione delle comunit? lacustri
Feeding on the roof of the world: the first gut content analysis of very high altitude Plecoptera
The biology of Plecoptera from high altitude Himalayan freshwaters is almost unknown. Very few and sporadic studies have been devoted to these insects, and exclusively with a taxonomic approach. We provide information on the feeding of Capnia nymphs from three lakes localized above 4,800 m a.s.l. (NE Nepal). Nymphs from these high altitude lakes feed mainly on fine detritus, acting as collector- gatherers, with the accidental ingestion of mineral matter, mostly in larger specimens. It is likely that the harsh environmental conditions in our study area create an environment unfavorable to both the allochthonous input of coarse particulate organic matter (such as terrestrial leaves) and the autochthonous input related to aquatic primary productivity, so that these nymphs feed on small organic particles that originates mainly from the catchment
A macro-ecological approach to the study of the vulnerability of aquatic environments to nonindigenous species: a case study by the Virtual Research Infrastructure LifeWatch Italy
LifeWatch, the European Virtual Biodiversity Research Infrastructure, is a reference point for researchers, policy makers, public authorities and enterprises operating in the field of protection, management and the sustainable use of biodiversity and ecosystems. LifeWatch Italy has proposed a European-level case study designed to assess the vulnerability of aquatic and terrestrial ecosystems to the arrival of non-indigenous species (NIS), in order to demonstrate the functionality of the e-infrastructure and its potential. Here we present the results of a first analysis conducted, on a national scale, on NIS presence in various typologies of aquatic environments (freshwater, transitional and marine), aimed at verifying the link between vulnerability to NIS and human activities. Each of these environments is diversely affected by the NIS problem, which is of great interest both at national and international level, showing different rates of biodiversity alteration. To understand the mechanisms that cause the NIS success and to find adequate means of prevention, the LifeWatch community proposes a macro-ecological approach. It analyzes the drivers of NIS occurrence and the role played by climate change in facilitating their spread, so as to provide solutions that will lead to their reduction by applying effective measures for biodiversity conservation. The data used refer to a 30-year time span and include several taxonomic groups. All analyses were performed using dedicated R packages, which are one of the services provided by LifeWatch on the web
Tools for the development of a benthic quality index for Italian lakes
In this paper, we propose a methodology to develop a benthic quality index useful for Italian lakes. The existing data about benthic macroinvertebrates of the Italian lakes were collected over a period of 50 years, but only a few lakes such as the Maggiore and the Mergozzo have been intensely studied. Some large lakes such as Lake Como are still almost uninvestigated. In total, 570 benthic macroinvertebrate taxa were identified; of which 373 belong to Chironomidae and 85 to Oligochaeta. With the aim of relating environmental variables with macrobenthos assemblages, we carried out a canonical correlation analysis (CANON) using a database that included 1060 sampling points. Both environmental (13 variables describing morphometry and hydrochemistry) and biological data (57 taxa) were available, but only taxa present in at least 10 samples were selected for data analysis. Three canonical variates were ecologically significant. The first one was correlated with conductivity, pH and alkalinity and accounted for 20% of the total variation. The second one was positively correlated with total phosphorus and N-NH4, and inversely with dissolved oxygen, and accounted for 18% of the total variation. The third one showed a direct correlation with maximum lake depth and volume and an inverse correlation with water temperature, and accounted for 17% of the total variation. A Trophic Status Index (TSI), based on the table 11 of the Italian Law 152/99 (without including chlorophyll), was calculated by ranking percent oxygen saturation, transparency and total phosphorus. TSI was used to test a Benthic Quality Index for Italian Lakes (BQIL) which is proposed in the present paper. The algorithm considered three steps. First, the means of three variables were calculated: percent oxygen saturation, transparency and total phosphorus weighted by the taxa abundances. These values are interpreted as optimum for each taxon and used to assign an indicator weight (BQIW). Second, the mean of these three variables was calculated for each taxon (mean BQIW). Third, the mean BQIW was multiplied by taxa abundance and divided by the total number of specimens present at each site for which the BQIL was obtained. Using a regression between BQIL and TSI values, lake sites were assigned to 5 quality classes as required by the Italian Law 152/99 and the WFD 2000/60/CE. This assignment must be considered as tentative, because different lake types should be considered separately to develop an index. At present the lack of information from different lake typologies hinders the development of a more sophisticated index such as the French Lake Biotic Index (LBI).Studio iniziale per la messa a punto di una metrica (indice di qualit?) delle acque dei laghi Italiani con l\u27utilizzo del macrobenthos per l\u27assegnazione dei suddetti laghi a 5 categorie di qualit?, cos? come previsto dalla Direttiva Quadro sulle Acque (WFD 2000/60/CE). Sono presentati dati abiotici (parametri considerati dalla Legge 152/99) e biotici che sono risultati correlati all\u27idrochimica lacustre. Nel lavoro si evidenziano carenze sulla presenza di alcune tipologie lacustri presenti in Italia
Status quo of knowledges on Italian high altitude lacustrine macroinvertebrates
High altitude lakes and their fauna are one of the most threatened and less investigated
ecosystems in Italy. Alpine lakes are highly influenced by climate harshness and by air
pollution, and because of their small dimensions are extremely vulnerable to global climate
warming. Italy, in addition to the Alps, hosts another mountain range: the Apennines,
reaching in some cases comparable altitudes, and therefore subject to the same risks.
Moreover, the gentler slope of the Apennines makes them extremely vulnerable even to
direct human impacts. In the present work, for the first time, high altitude lakes belonging
to the Alps and to the Apennines are compared to highlight which meteo-climatic or
chemical characteristics could be considered key drivers for their macroinvertebrate
structure. The study area was explicitly focused on natural lakes placed above 1300 m of
altitude and above the 44\ub0 parallel, thus in the alpine area and subject to a continental
climate. 25 lakes were chosen (19 in the central-western Alps and 6 in the Modenese
Apennines) with surface areas lower than 1 km2 and with maximum depths lower than 15
m. Physico-chemical parameters and macroinvertebrates were studied and compared.
Samples were taken through the use of a hand-net (250 \u3bcm mesh size) along the littorals
on different substrates following standardised methodologies during the richer-fauna
season to allow an easier identification of species. Parallel to that, water samples were
collected and analysed. Species richness and the Taxonomic Distinctness Indices were
applied to underline the different complexity of the community structure of the two areas.
Results showed different macroinvertebrates communities with peculiar characteristics and
highlighted a more structured and diverse composition on the Apennines. Predictive
models on the future climate scenarios show how the peninsular portion of Italy will be
even more affected by the increase in temperatures than the Alpine area. Thus, this work
could be highly informative, mainly for central Italy, where proximity to towns encourage
tourists to reach these type of lakes, even if placed in protected areas or parks. Therefore,
protection and management plans, and conservation efforts of high altitudes cannot
overlooked a thorough understanding of the biological diversity of these environments,
which still appears fragmented and limited to some sector of the Alps. Furthermore, the
fundamental role of high altitude lakes as water resource needs a specific management
regime, as they are not included under the monitoring programs of the Water Framework
Directive legislation
Which future for Italian high altitude lakes?
Abstract: High altitude lakes and their fauna are one of the most threatened and less
investigated ecosystems in Italy. Alpine lakes are highly influenced by climate harshness
and by air pollution, and because of their small dimensions are extremely vulnerable to
global climate warming. Italy, in addition to the Alps, hosts another mountain range: the
Apennines, reaching in some cases comparable altitudes, and therefore subject to the
same risks. Moreover, the gentler slope of the Apennines makes them extremely
vulnerable even to direct human impacts. In the present work, for the first time, high
altitude lakes belonging to the Alps and to the Apennines are compared to highlight which
meteo-climatic or chemical characteristics could be considered key drivers for their
macrinvertebrate structure. The study area was explicitly focused on natural lakes placed
above 1300 m of altitude and above the 44° parallel, thus in the alpine area and subject to
a continental climate. 25 lakes were chosen (19 in the central-western Alps and 6 in the
Modenese Apennines) with surface areas lower than 1 km2 and with maximum depths
lower than 15 m. Physico-chemical parameters and macroinvertebrates were studied and
compared. Samples were taken through the use of an hand-net (250 μm mesh size) along
the littorals on different substrates following standardised methodologies during the richerfauna
season to allow an easier identification of species. Parallel to that, water samples
were collected and analysed. Species richness and the Taxonomic Distinctness Indices
were applied to underline the different complexity of the community structure of the two
areas. Results showed different macroinvertebrates communities with peculiar
characteristics and highlighted a more structured and diverse composition on the
Apennines. Predictive models on the future climate scenarios show how the peninsular
portion of Italy will be even more affected by the increase in temperatures than the Alpine
area. Thus, this work could be highly informative, mainly for central Italy, where proximity
to towns encourage tourists to reach these type of lakes, even if placed in protected areas
or parks. Therefore, protection and management plans, and conservation efforts of high
altitudes cannot overlooked a thorough understanding of the biological diversity of these
environments, which still appears fragmented and limited to some sector of the Alps.
Furthermore, the fundamental role of high altitude lakes as water resource needs a
specific management regime, as they are not included under the monitoring programs of
the Water Framework Directive legislation
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