La flora del distretto minerario di Montevecchio (Sardegna sud-occidentale)

Abstract

IntroduzioneIl bacino minerario di Montevecchio, conosciuto e sfruttato fin dal tempo dei romani, ha rappresentato per gran parte del XX secolo il maggiore centro di estrazione di piombo e zinco in Italia (Mezzolani & Simoncini, 2001). I duemila anni di sfruttamento di queste colline hanno avuto un impatto ambientale visibilmente devastante lungo tutto lo sviluppo del ricco complesso filoniano, tanto più che la chiusura delle miniere non è stata accompagnata da adeguati interLa flora del distretto minerario di Montevecchio (Sardegna sud-occidentale) Accettato il 4 dicembre 2006The flora of the mining district of Montevecchio (SW-Sardinia) -A contribution to the knowledge of the flora of the mining district of Montevecchio is reported, focussing on the plants colonizing highly polluted substrata, produced or altered by the mining activity. In the present survey, 373 taxonomic units have been recorded, ranking as follows: 332 species, 36 subspecies, 3 varieties, 2 hybrids. On old racking basins and dumps, 192 taxa have been recorded: 170 species, 20 subspecies, 1 variety, 1 hybrid. Further 181 taxa (162 species, 16 subspecies, 2 varieties, and 1 hybrid) are missing on racking basins and dumps, but grow, however, in the nearby areas. The surveyed taxa belong to 73 families and 252 genera, but only 53 families and 146 genera are represented on racking basins and mining dumps. The top three families are: Asteraceae (42 taxa, 11,3% of the total), Fabaceae (36 taxa, 9.7%) and Poaceae (28 taxa, 7.5%). The top three genera are: Trifolium and Ophrys (8 taxa), followed by Euphorbia (6 taxa). The biological spectrum highlights the remarkable Mediterranean connotation of the investigated district, being the therophytes 42,1% of the whole flora, followed by the hemicryptophytes (22,5%). The chorologic spectrum is dominated by the Mediterranean chorotype (56.6%), including circum-Mediterranean (39.4%), W-Mediterranean (8.0%) and endemic taxa (7.2%). Further 22.3% of the surveyed taxa have a wider distribution range, but centered, however, in the Mediterranean region. As concerns the endemics, 26 taxa have been found, of which 21 species and 5 subspecies. Asteraceae and Scrophulariaceae resulted the richest in endemic taxa (3 units each). Most of the recorded endemics have a Tyrrhenian-insular distribution; with reference to the biogeographic units of the Mediterranean region, they belong to the Italo-Tyrrhenian superprovince.Key words: Italy, mining polluted substrata, Sardinia, vascular flora.venti di bonifica e mitigazione degli impatti.L'attività mineraria è, infatti, una tra le attività industriali che maggiormente possono danneggiare, inquinare e modificare più o meno permanentemente il paesaggio, compromettendo anche attività produttive quali agricoltura, pastorizia e pesca.Il distretto minerario di Montevecchio si presenta tuttavia peculiare rispetto alle altre principali aree estrattive della Sardegna. L'attività mineraria è infatti andata a inserirsi in un contesto ambientale e paesaggistico caratterizzato da elevata...

La flora del Monte Arcuentu (Sardegna sud occidentale)

“…Una prima analisi dei tipi vegetazionali indica come la potenzialità del territorio sia per la serie climatofila del Prasio majoris-Querco ilicis Σ e alle quote più elevate per il Galio scabri-Querco ilicis Σ, mentre nelle zone pedemontane, con suoli più profondi, si rinviene la serie edafofila del Galio scabri-Querco suberis Σ (Bacchetta et al, 2007).…”

Use of native species and biodegradable chelating agents in the phytoremediation of abandoned mining areas

“…The plant selection was based on previous field studies related to geobotanical aspects of SW-Sardinia mining areas [2,3,4] and was directed to choose metal tolerant plants which develop enough biomass to decontaminate the soil in acceptable times. Three little shrub species that often occur on contaminated substrata were selected.…”

“…In Sardinia (Italy) the closure of mining activities caused serious threats as a result of the insufficient attention on the possible environmental impacts and of the inadequate definition of pollution containment plans. In particular the area of Sulcis-Iglesiente is the most important metalliferous region in Italy, in which hundreds of mining dumps exist and the volume of abandoned and contaminated materials is more than 70 millions of m 3 . Phytoremediation can be considered a good solution for soil remediation in these areas because it can be used as an in situ low cost technique but requires a long remediation time.…”

Flora vascolare del Capo di Monte Santu (Sardegna centro orientale)

“…Vegetational data were obtained from field-research carried out in spring and summer [2003][2004][2005] and from recent publications (Bacchetta et al, 2007a(Bacchetta et al, , 2007b. 120 phytosociological relevés were taken on thè whole mining district and namely on substrata resulting from thè mining activity such as mining dumps, surface mines and tailing dams.…”

“…Bacchetta et al (2007b) described those special series and distinguished two of them: thè first one develops on dumps made of gravely-pebbly and loose materials, generally with high slope; thè second one lays on fine substrata with high water retention, settled in watershed on mining dumps and on tailing dams. In both cases, thè first stage of thè series are thè therophytic communities, after that thè garrigues of Ptilostemono casabonae-Euphorbion cupanii alliance develop and then thè syntaxa referred to Teucrion marialliance.…”