9,680 research outputs found
Robinia pseudoacacia L. in the forested agricultaral landscape pf the Pisan hills (Tuscany)
No full textThis study is part of a larger research project on transformations in the forested agricultural landscape of the Pisan Hills in the course of the last 50 years. Over time, both soil utilization for agricultural purposes and spontaneous ground cover have undergone substantial change and fluctuation in terms of the area occupied (Bertacchi and Onnis 1995). One major aspect concerns Robinia pseudoacacia L, an exotic species of North American origin naturalized in Tuscany. Although its presence in Tuscany was reported as early as the beginning of the 1800s (Savi 1801), it has spread extensively over vast stretches of formerly agricultural but now abandoned land, often giving rise to monophytic populations. In many cases the Robinia pseudoacacia populations have fully replaced the original phytocenoses
Dune habitats of the Migliarino – San Rossore – Massaciuccoli Regional Park (Tuscany – Italy)
No full textHere we present a map of dune habitats (in accordance with Directive 92/43/EEC, MD 20 January 1999) developed from a long-term survey of dune vegetation in the Migliarino San Rossore Massaciuccoli Regional Park, northern Tuscany, Italy. The 1:7500 map covers a total area of about 394 ha, was created in the geographical information system environment for print and digital versions. The aim of this work, in addition to outlining the current vegetation landscape in the printable map, is to monitor changes in dune habitats on the digital version. Phenomena such as coastal erosion and human pressure can be monitored in order to identify appropriate management tools for mitigating or eliminating disturbance factors.
The shape and spatial coverage of habitats, identified by previous vegetation surveys in the field, were drawn on the basis of orthophotos using MapInfo®. The study reveals numerous highly significant habitats in terms of conservation, which are often significantly altered in terms of their distribution and surface area due to human activities and coastal erosion
UAVs Technology as a Complementary Tool in Post-Fire Vegetation Recovery Surveys in Mediterranean Fire-Prone Forests
No full textForest fire is a recurring and serious environmental hazard, which is often due to the interaction between anthropogenic activities and climate change, despite having always characterized the vegetation landscape in the Mediterranean area. Alongside the required prevention and control works, there is an increasing need for post-fire monitoring. This is particularly relevant when it comes to natural or semi-natural forests, so that inappropriate reforestation is not undertaken without having well understood the dynamics of self-regeneration and the resilience of pre-existing phytocoenoses to fire. These monitoring operations often take a long time, but a quick picture of the severity of the fire and the response of the vegetation is also required. In this context, the data relating to post-fire surveys on a maritime pine forest of Monte Pisano (northern Tuscany, Italy), obtained from ground surveys and drone shots, are reported. This investigation showed: (1) UAV technology has proved to be very useful and fast, and it allows a good identification of tree/shrub species and forest structural parameters. (2) In these forests, repeated fires cause the disappearance of pine woods ad substitution with “pyroclimax” cork oak communities in equilibrium with a regime of repeated fires. (3) These first results, part of an ongoing investigation, contribute to a better understanding of the sylvogenetic processes following the passage of fire and can support the management of burned areas
Cork oak (Quercus suber) in the dynamism of a forest landscape shaped by fire on Monte Pisano (Tuscany N-W, Italy)
No full textThe plant landscape of Monte Pisano is characterized by a predominant forest component, with Pinus pinaster and Castanea sativa, of clear anthropic imprint. Another important component is constituted by dynamically advanced scrubs and woods of evergreen sclerophylls of natural origin, although often differently altered by the anthropic action and/or by fires, and dominated by Quercus ilex. Quercus suber is often found within holm oak woods, and – with lower frequency – inside the pine forests. Cork oak, in some cases, becomes dominant going to constitute the northernmost cork forests in Tuscany. The frequency of fires in Monte Pisano in the last decades seems to have led to an increase in Q. suber surface due to its known resilience to wildfires. The aim of this research is: a) to define the distribution of Q. suber in the area also in relation to repeated fire events in the past; b) to provide an updated characterization of these stands using a phytosociological approach; c) to identify stands and groups of trees that can be used as "seed forests" for post-fire forest restoration purpose, in relation to their marginal population characteristic. The study suggests a relationship between the spread of cork oak and the historical pattern of fires. This wide spread should be protected by forms of forest management unfortunately absent in this territory
Analisi diacronica delle trasformazioni a carico dell‘ambiente dunale di Tirrenia (PI) - 1954-2010.
No full textANALISI DIACRONICA DELLE TRASFORMAZIONI A CARICO DELL’AMBIENTE DUNALE DI TIRRENIA (PI) - 1954-2010
A. BERTACCHI, T. LOMBARDI
Dipartimento di Agronomia e Gestione dell‘Agroecosistema – Via San Michele degli Scalzi 2 -56124 Pisa- Università di Pisa. [email protected]
Attraverso il confronto di aerofoto storiche (Volo GAI 1954, volo EIRA 1975) e recenti (Volo Regione Toscana 2010), oltre ai rilevamenti di campo, sono state evidenziate le trasformazioni a carico degli ambienti dunali di un tratto del litorale pisano di Tirrenia. Nel 1954 l‘area non risultava interessata da fenomeni di urbanizzazione particolarmente rilevanti e il sistema dunale, sebbene già parzialmente interessato da fenomeni di occupazione antropica, era ancora ben rappresentato; la fotointerpretazione del volo 1954 evidenzia infatti una morfologia dunale (duna embrionale, mobile e consolidata) integra per oltre il 70 % e la presenza di una zonazione vegetazionale ancora distinguibile. Negli anni ‘70, all‘espansione dell‘edilizia residenziale nelle zone retrostanti la spiaggia, si aggiunge un progressivo e importante consumo dell‘arenile da parte degli stabilimenti balneari. Dalle aerofoto del ‘75 l‘assetto urbanistico e le principali trasformazioni dell‘arenile, appaiono fondamentalmente coincidenti con l‘attuale.
Da quanto si evince dall‘analisi delle aerofoto contemporanee e con la verifica dei rilevamenti in campo, la trasformazione antropica ha portato alla totale scomparsa della fascia dunale embrionale e mobile, mantenendosi ancora solo il 34 % dell‘intero sistema primigenio, con una occupazione stagionale dell‘arenile completa. La forma dunale sopravissuta è rappresentata quasi esclusivamente dalla duna consolidata interna con perimetrazioni effimere di duna embrionale/mobile. Da evidenziare che in ogni caso, il sistema dunale sopravissuto, risulta sempre sbarrato dagli stabilimenti balneari nella sua naturale continuità spaziale con l‘arenile .
Pur essendo presente ancora una flora psammofila ben rappresentativa - per tipo di specie - del litorale tirrenico centrosettentrionale, le comunità vegetali presenti, risultano quasi completamente azzerate, presenti in modo puntiforme e alterate nella loro normale composizione specifica. Quanto rimane della duna consolidata sembra rappresentare un ―rifugio‖ alle specie psammofile che tuttavia, in questo contesto, non riescono quasi mai a dare luogo a associazioni definite. Dove sopravvivono ancora lembi della duna mobile, si possono rinvenire in rapida successione spaziale elementi dell‘associazione Salsolo kalii-Cakiletum maritimae Costa & Manz 1981 corr. Riv.-Mart. et al. 1992, compenetrati a mosaico con elementi dell‘associazione Echinophoro spinosae-Elymetum farcti Gehu 1988 ed elementi dell‘Echinophoro spinosae - Ammophiletum arundinaceae Gehu, Rivas-Martinez, R.Tx 1992. Più consistenti ed individuabili le associazioni tipiche della duna consolidata quali l‘Asparago acutifolii-Juniperetum macrocarpae (R. et R. Molinier 1955) De Bolos 1962 a cui si associano popolamenti a Helichrysum stoechas, a contatto catenale con macchie a Cistus sp.l. e Phillyrea angustifolia. In questo contesto, elevata l‘ infestazione di specie invasive, esotiche o sinantropico-ruderali, a causa delle ripetute opere di urbanizzazione.
L‘analisi del livello di degradazione antropica, attraverso un l‘elaborazione di un indice ponderato, su transect ripetuti ad intervalli regolari lungo la spiaggia, ha evidenziato un alterazione totale pari a ca il 45% dell‘area, soprattutto per la mancata continuità della naturale sezione morfologica dunale ortogonale alla linea di costa
UAV monitoring of the spread of Juniperus macrocarpa on the dunes of NW Tuscany
No full textJuniperus macrocarpa Sm. is a shrub or small tree typical of stable dunes and cliffs in the Mediterranean region (1). The species is diagnostic, constant, and dominant of EUNIS habitat N1B with a VU (vulnerable) status (2). Although not considered an entity at risk, its distribution and habitat in Tuscany show a great discontinuity, due to high anthropic pressure and/or erosion. Here J. macrocarpa in some areas has almost vanished due to erosion, in others, it is threatened by tourist pressure, in others still, instead, is expanding. In this survey, we report data related to the fast spread of juniper observed in Marina di Vecchiano (PI), a sandy coast in the north part of the MSRM Regional Park
Il paesaggio agroforestale tra conservazione ed evoluzione. L'area di Filattiera (MS) 1944-2004
No full textVengono esaminate, attraverso il confronto di aerofotografie storiche e recenti, le trasformazioni a carico del paesaggio agroforestale di un area della Toscana nord-occidental
Diachronic analysis (1954–2010) of transformations of the dune habitat in a stretch of the Northern Tyrrhenian Coast (Italy)
No full textThe aim of this work is the diachronic analysis, over the past 60 years, of the vegetation changes in dune environments of a stretch of Tuscan coast. Aerial photos of the years 1954 and 2010 were compared using photointerpretation and GIS software, and phytosociological surveys in the field were carried out. In addition to the spatial dynamics of the identified phytocoenoses, we have analyzed the different degrees of anthropogenic alteration of the examined area by the development of a synthetic index already used in neighboring contexts. The results showed with respect to the past, a deep morphological transformation of the dune system, and a consequent high spatial contraction and fragmentation of psammophilous plant communities. Today, indexed values of anthropogenic alteration, although particularly high especially when compared historically, are mitigated by the marginal and punctiform permanence, in few of those dune areas spared from urban infrastructure, of the main psammophilous plant associations typical of Tyrrhenian coast
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