Historical GIS as a Tool for Monitoring, Preserving and Planning Forest Landscape: A Case Study in a Mediterranean Region

In order to assess the dynamics of forests and the effectiveness of their management strategies, it is necessary to develop monitoring systems based on qualitative and quantitative tools for their conservation, valorization and restoration. This approach is particularly important for areas that have undergone intense anthropogenic transformations in the last century. In order to do this, it is first necessary to apply a chronological methodology based on historical GIS that allows the integration of different types of geodata. As a result of constantly evolving spatial analysis tools, the monitoring of landscape forest evolution is increasingly more effective and complete. Using as a case study a region representative of common processes of other Mediterranean areas (Southern Italy–Basilicata region), a diachronic analysis of 156 years was applied to evaluate the forest landscape dynamics. Starting from historical cartographies to remotely sensed data available online, a GIS-based approach was implemented to evaluate the spatial and statistical variations of the forest landscape. In this way, it was possible to assess how much, where and how the forest landscape has changed in order to provide a methodology to support more detailed and sectoral studies.

Lepidoptera wing scales: a new paleoecological indicator for reconstructing spruce budworm abundance

Natural disturbances have a major impact on boreal forest landscape dynamics, and although fire history is well documented at the Holocene scale, spruce budworm (Choristoneura fumiferana (Clemens)) (SBW) dynamics have only been known for the last three centuries. This is likely due to the difficulty in using and interpreting existing indicators (cephalic head capsules and feces). In this methodological study, we present an original approach using lepidopteran wing scales to reconstruct insect abundance. We analyzed two sediment cores from the boreal forest in central Quebec and extracted wing scales at every stratigraphic level. The required quantity of sediment for paleoecological analysis is relatively small given the large quantity of wing scales produced by Lepidoptera and their small size. Scales are well preserved due to their chitinous structure and their great variety of shapes offer a high potential for taxonomic identification. A statistical model based on the shape of scales of the three major epidemic lepidopterans in Quebec discriminated 68% of SBW scales. This indicator allows a more efficient and more precise reconstruction of SBW history with respect to the use of cephalic head capsules or feces.