1,720,966 research outputs found
Un’attività di Educazione Ambientale: la realizzazione di un boschetto planiziale nel giardino scolastico
Full text linkQuindici anni fa, nel 1997, in un istituto superiore di Venezia Mestre si intraprese un progetto di Educazione Ambientale. Si ripercorrono le vicende che portarono alla realizzazione di un boschetto all’interno del giardino scolastico, e si riportano risultati, considerazioni ed indicazioni di questa esperienza “sul campo”. Nell’ambito di tale progetto, è stata realizzata una chiave di identificazione semplificata per il riconoscimento di una sessantina di specie legnose presenti in un bosco planiziale
Correzione - Aggiornamento Consistenza, distribuzione e dinamica di popolazione di Myricaria germanica (L.) Desv. nella Regione Trentino-Alto Adige/ Suedtirol
Full text linkNella realizzazione della ricerca delle popolazioni di Myricaria germanica nella Regione Trentino-Alto Adige / S dtirol, nonostante l’impegno e gli sforzi profusi, resi dif coltosi dalla variabilità geomorfologica dell’ambiente fluviale, inevitabilmente c’era il rischio di incorrere in qualche imprecisione o svista, di cui si riporta, nel presente articolo, la correzione. Inoltre, nuovi rilevamenti condotti nel 2015 e le mutate condizioni ecolo- giche dell’ambiente uviale hanno determinato la necessità di aggiornare, col presente articolo, i dati già pubblicati nel 2014. La corretta interpretazione delle correzioni e degli aggiornamenti va compiuta facendo riferimento a Michielon & Sitzia (2014)
Presenza di Myricaria germanica (L.) Desv. lungo il torrente Avisio (Trentino, Italia settentrionale)
Full text linkMyricaria germanica (L.) Desv. (German tamarisk) is an integral part of the ecological dynamics of non-regulated rivers, wich are characterized by annual flooding, and low water levels in summer. During the last century damming and regulation have interrupted the original riparian dynamics, reducing the German tamarisk natural habitats. The species is endangered Myricaria germanica in the Trentino region and its distribution is concentrated along the Avisio river, where
the main habitats are grave) and sandy banks. This work describes the last remaining populations of Myricaria germanica in the Trentino region
Consistenza, distribuzione e dinamica di popolazione di Myricaria germanica (L.) Desv. nella Regione Trentino-Alto Adige/Südtirol
No full textMyricaria germanica (L.) Desv. (German tamarisk) is a riparian bush associated to pioneer ecosystems of non-regulated rivers. M. germanica is an endangered indicator species of Alpine rivers that reflects riverine landscape diversity. In Trentino-Alto Adige/Südtirol Region M.germanica was historically common along alpine rivers, but during the last century damming and river regulation have interrupted the original riparian dynamics, reducing the German tamarisk natural habitats and today the species is endangered. This work describes the remnant populations of M. germanica in Trentino Alto Adige/Südtirol Region. The aim of this research was to assess the presence, vitality, and size of tamarisk’s populations and to investigate the relationship between their presence and the natural and anthropogenic factors shaping the river system.
As a first step, we made an inventory of the known sites of M.germanica. The field surveys were carried out during the summer period of the years 2009-2014 and included most of the Trentino- Alto Adige/Südtirol rivers. Today, in all Trentino-Alto Adige/Südtirol Region, 10 sites have more than 100 German tamarisk plants and 20 have a few plants, often with no more than 10 plants, decreasing and without regeneration. In order to prevent extinction, the remnant populations should be adequately controlled. The maintenance and preservation of dynamic river conditions is the key for the conservation of M. germanica populations, otherwise the current disjunct distribution could become even more fragmented
Traslocazione di Myricaria germanica (L.) Desv. in Alto Adige / Südtirol
Full text linkIn the late nineties of the twentieth century, the provincial of ces for hydraulic works of the Autonomous Province of Bolzano-South Tyrol began planting shrubs of Myricaria germanica (German tamarisk) as a measure complementary to river works in several sites in the province, using about 4000 tamarisks. This work for the rst time, analyzes the results of these actions, highlighting successes, failures and problems
Conservation of the endangered Myricaria germanica (L.) Desv.: a keystone species of riverine habitats
Full text linkMyricaria germanica (L.) Desv. is a pioneer shrub linked to natural river dynamics. Despite its high conservation and indicator value, there is a lack of information on factors affecting its population density and viability, and its long-term dynamics. The long history of river alteration has created novel systems with unknown dynamics, so population-level studies are necessary to understand, manage and restore M. germanica, preventing the loss of biodiversity associated to this keystone species. The main process that affects its populations is habitat fragmentation, especially in human dominated European rivers.
This thesis is based on a general review that deals with the distribution, biology and ecology of M. germanica (Paper I). Two research papers (Papers II and III) then concern the evaluation of M. germanica population-level long-term dynamics along a central eastern Alpine river (Trento Province, Italy) subject to human impact and lateral river corridor constraints. The success of a set of reintroduction projects in South Tyrol, a central eastern Alpine region, was also investigated through the collection of post-reintroduction population-level data. Lastly, a set of individual river basin traits data was collected in four north-eastern Italian basins and summarized, to complement the knowledge of this species biology. The last two topics are integrated into this main text.
Focusing on different time scales, due to the variability of riverine landscape contexts and on different spatial levels, from individual-, to river-, to regional levels, the overall goal of this work was to detect spatial and management components influencing M. germanica survival.
The analyses were conducted at European level (Paper I), on about 20 metapopulations distributed along a river basin (Papers II and III), 50 reintroductions were monitored (4,730 planted individuals), and traits were measured on 1,634 individuals. Papers II and III were written thanks to a collaboration with the University of Helsinki (Department of Environmental Sciences).
The data collection covered both species and environmental variables, considering current and historical field data and management variables of the surveyed river corridor and the surrounding basin-level asset. Regression models were used to relate species dynamics and traits to spatial, environmental and management variables. Descriptive statistics were used to summarize the morphological and chronological traits.
The approximately 150 literature sources for this species span four centuries, ten languages, and three continents, apart from the richness of biological and ecological data, they are full of forgotten information about the potential uses of this species (Paper I). Environmental site conditions (particularly active channel width) and management variables have an impact on plant populations, the response of which however does not follow a clear spatial synchrony. This requires a long-term approach in studying population survival and a distinction between adults and juveniles (Papers II and III). Currently, reintroductions have had a mixed success, positive in specific locations, while the majority of individuals disappeared in the years following their planting. Morphological traits are characteristic of a short-lived shrub, but some long-lived individuals have been observed, usually away from rivers. Despite this, height, diameter and age were well correlated.
In general, the integrative method used allowed us to improve the knowledge about the drivers of M. germanica survival, the complex natural-human patterns and processes on different time-space scales that influenced population-level abundance and basin-level distribution
Il 'Bosco Bruno', bosco planiziale di Mestre (VE): una guida interattiva alle piante legnose
No full textLa presente guida, realizzata per il ‘Bosco Bruno’, piccolo bosco planiziale piantumato in ambito scolastico, permette in generale l’identificazione delle piante legnose presenti negli imboschimenti di pianura, autoctone, avventizie e aliene, per un totale di 91 specie, e si presta per essere utilizzata anche per il Bosco di Mestre
Myricaria germanica in quattro bacini idrografici alpini dell'Italia nord-orientale
Full text linkMyricaria germanica in four alpine river basins of north-eastern Italy
The article provides a picture, updated to 2017, of the presence, abundance, distribution
and characteristics of the populations of Myricaria germanica in northeastern Italy in
146 sites distributed in four watersheds (Adige, Brenta, Piave, Tagliamento), subject to
different levels of natural and anthropogenic disturbance, but comparable in terms of
climate, geology and biogeography. It describes the influence of human activities on
river geomorphology and its interactions with M. germanica scrub (habitat Natura 2000
3230), assessing its current threats and future prospects
Population dynamics of the endangered shrub Myricaria germanica in a regulated Alpine river is influenced by active channel width and distance to check dams
No full textDespite its high conservation and indicator value, there is a lack of information on the long-term dynamics of Myricaria germanica (L.) Desv. (German tamarisk), and of factors affecting its population density and viability. Here we studied the dynamics of adult and juvenile M. germanica at 19 sites during a seven year period (2009-2015) along a 30 km long stretch of an Italian Eastern Alpine river, by assessing a set of anthropogenic and geomorphological factors. Adult (239-571 individuals) and juvenile (62-292 individuals) population numbers showed no significant difference between years, and a remarkably uneven distribution among sites. Yet, several remnant populations have declined or disappeared in recent years and a few populations have increased. We found a positive effect of the width of the active channel on adult and juveniles plants. This means that anthropogenic river narrowing is a leading cause of the decline of the species along river banks. For juveniles, abundance also decreased with distance from downstream check dams. We conclude that in the regulated river studied, the conservation of M. germanica appears to be possible not only as a result of natural flow dynamics, but also at an artificial sediment storage area with a semi-natural river dynamic that maintains favourable riverine habitats. Our results are useful in a decision-making framework for the conservation of M. germanica, for river restoration and for flood protection in alpine valleys
Comparing ecohydrological processes in alien vs. native ranges: perspectives from the endangered shrub Myricaria germanica
Full text linkComparing the ecology of woody species in their alien and native ranges may provide interesting insights for theoretical ecology, invasion biology, restoration ecology and forestry. The literature which describes the biological evolution of successful plant invaders is rich and increasing. However, no general theories have been developed about the geomorphic settings which may limit or favour the alien woody species expansion along rivers. The aim of this contribution is to explore the research opportunities in the comparison of ecohydrological processes occurring in the alien vs. the native ranges of invasive tree and shrub species along the riverine corridor. We use the endangered shrub Myricaria germanica as an example. Myricaria germanica is an Euro-Asiatic pioneer species that, in the native range, develops along natural rivers, wide and dynamic. These conditions are increasingly limited by anthropogenic constraints in most European rivers. This species has been recently introduced in New Zealand, where it is spreading in some natural rivers of the Canterbury region (South Island). We present the current knowledge about the natural and anthropogenic factors influencing this species in its native range. We compare this information with the current knowledge about the same factors influencing M. germanica invasiveness and invasibility of riparian habitats in New Zealand. We stress the need to identify potential factors which could drive life-traits and growing strategies divergence which may hinder the application to the alien ranges of existing ecohydrological knowledge from native ranges. Moreover, the pattern of expansion of the alien range of species endangered in their native ranges opens new windows for research
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