Landscapes Forest and Global Change - ESA - Escola Superior ...

G. Puddu et al. 2010. Landscape transformations seen through the historical cartography: Sardinia as case study
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particular, (due to the great number of points) has introduced errors that have been estimated
lower than map scale precision.
2.1.2 Map of land utilization made by National Research Counsil, Italian Cadastre, and
Italian Touring Club.
The second map used in this work, is called “Map of land utilization” realized by a cooperation
between National Research Council (CNR), Italian Cadastre (Catasto) and the Italian Touring
Club (TCI) and it has been released in 1952-1960. This map can be assimilated to a land use and
land cover map, even if the legend, made by 21 items, cannot be completely compared with that
one of the European CORINE Project (Falcucci et al. 2007). Different opinions exist about its
original setting and, actually, the real thematic aggregation criteria, that led to the final map
(1:200000 scale) starting from all he information contained in the single sheets of the Italian
Cadastre (1:1000; 1:2000; 1: 4000 scales), are not known
2.1.3 The CORINE Land Cover map
The third map used for comparisons, is derived from CORINE Project, that, for Italy, produced
a digital map at the nominal scale of 1:100000 with 44 legend items.
2.2 Model development
To develop a model for a diachronic comparison between different cartographic maps, it’s
necessary to obtain the best compatibility between them, even heterogeneous in legend and
elaboration methods (topographic survey vs aerial and satellite photos analysis) that can be
realized according to the procedures of map generalization (Weibel and Jones 1998)
summarized in three consequential phases (Petit and Lambin 2002; Pelorosso et al. 2009). Due
to the different structure of legends in the maps used, thematic generalization could be obtained
only reducing all the items into two classes: wood vs non-woods. Spatial resolution
generalization was derived by a rasterization on the same DTM at a 20x20 m of resolution. For
every map, consequential aggregations were achieved starting from 40 m cells with a step of 20
m until 500 m cells were reached using the majority rule and giving rise to 24 maps for each of
the national cartographies. Using five landscape indexes (Riitters 1995) every aggregated map
can be analyzed and a distance can be elaborated in 5-dimensional space of landscape metrics
between the generalized and the target map. In this way, the best resolution can be identified to
make a comparison between target map (CLC, 1990) and generalized maps (Forest Map 1930-
1935; Map of Land Utilization 1952-1960). See Table 1:
Table 1. Comparison framework between maps.
Forest Map (1930-35) vs Map of Land Utilization (1952-60) MIL 040 ÷ MIL 500 → CNR-TCI 040
Forest Map (1930-35) vs CORINE (1990) MIL 040 ÷ MIL 500 → CORINE 1990 040
Map of Land Utilization (1952-60) vs CORINE (1990) CNR 040 ÷ CNR 500 → CORINE 1990 040
3. Results
The first obtained results, show a great reduction of forest extensions after the Second World
War, in a quite justifiable way. This collapse could be coherent with the extinction risk found
for different animal species linked to forestal ecosystems (e.g. Corsican Red Deer, Fallow Deer,
Forest Landscapes and Global Change-New Frontiers in Management, Conservation and Restoration. Proceedings of the IUFRO Landscape Ecology
Working Group International Conference, September 21-27, 2010, Bragança, Portugal. J.C. Azevedo, M. Feliciano, J. Castro & M.A. Pinto (eds.)
2010, Instituto Politécnico de Bragança, Bragança, Portugal.