Valsorda, Gualdo Tadino - Viola eugeniae Parl.
*G. Filibeck & A. Scoppola
Dipartimento di ecologia e sviluppo economico sostenibile (DECOS), Università degli Studi della Tuscia, Largo Università snc, 01100 Viterbo, Italia
Landscapes can be viewed as one of the levels in which biodiversity is hierarchically arranged; hence, it may prove important to develop lists of endangered landscape types. Among the landscape systems (sensu Blasi et al., 2000) of NW Lazio (C-Italy), two are particularly distinctive and biodiversity rich: the clayey-carbonate turbidite system (“Flysch della Tolfa”) and the pyroclastic-flow system (“Tufo Rosso”). The turbidite system, due to pedological features unfavorable to agriculture, and because of public property of land, shows a characteristic low density of human settlements (to an extent usually found in Italy only at much higher altitudes), and is therefore composed of ecosystems featuring many endangered and protected species. The pyroclastic system is characterized by unique land forms: flat plateaux divided by deep gorges with vertical slopes and flat bottoms. These features led to a typical and rich combination of plant communities: within a single gorge, we often found a toposequence ranging from Fagus sylvatica extrazonal stands to evergreen “macchia”. Until c. 1951, human settlements in the pyroclastic system were confined to the cliff tops, and the plateaux were almost deserted and exploited as sheep-grazing land. The two landscape types are in touch with each other through a long, geologically-driven boundary, which is very distinctive of NW Lazio. Such an interface influenced the shape and location of urban settlements, and originated a belt particularly rich in plant biodiversity. For centuries, traditional land-use practices have enhanced the differences in the assemblage of land-cover types between the two sides, hence increasing both visual distinctiveness and biodiversity across the interface. Structural patterns of both landscapes are nowadays endangered, due to land-use changes and urban sprawl: as a result, present-day development is blurring fast the difference between the two areas – the landscape interface as well should be viewed as a feature worth to be protected at landscape level. Based on the analysis of this case study, we provide some theoretical and methodological reflections on the problem of “landscape red-listing”, with some preliminary suggestions concerning the methods for landscape classification and for their “threat assessment”.
flysch, hierarchical land classification, Italy, landscape boundaries, landscape protection, land-use changes, pyroclastic flow, urban sprawl