Mapping the Urbanization Impact on a Regional Ecosystem: Historical Cartography on Invasion-Succession of Ligustrum lucidum in the Chaco Forest of Metro Córdoba (2001-2022)

SARA BOCCOLINI; VALERIA FENOGLIO

Sao Paulo

Conferencia; 2nd International and Interdisciplinary Conference on Spatial Methods for Urban Sustainability (SMUS Conference); 2022

The global center of spatial Methods for urban sustainability is fundation

The Sierras Chicas valley (Córdoba, Argentina) has faced for years the invasion of the nativeforest by the exotic species Ligustrum lucidum (glossy privet). This problem is directly related tothe urbanization processes in the region, specifically to urban forestry strategies that promotethe implantation of exotic species - especially Ligustrum - whose evergreen foliage contrastswith the deciduous flora of this semi-arid region. In recent years, the affected area has growthsignificantly, causing drastic changes in the local ecosystem: Ligustrum reproduces quickly andcompetes successfully with the native flora for water and sunlight, causing the loss of the nativeflora and fauna. Several studies record the evolution of this process since 1983; this is essentialto calculate the magnitude of the problem and the affected area over time. However, itsevolution in the 21st century has not yet been reconstructed, even when in these years SierrasChicas shows an exponential increase in its population and urbanized area, which wouldindicate a growing aggravation of the problem. Due to this, we propose to complete thehistorical record of the area occupied by Ligustrum between 2001 and 2022. To do this, weprocessed Landsat 8 and 9 satellite imagery obtained during dry season (between July-September), when the foliage difference between native forest and Lucidum is most notable: wecalculated the different levels of the Normalized Difference Vegetation Index in the territory,detecting both areas covered with Ligustrum and urbanized areas in 2001, 2006, 2010, 2016and 2022 with great level of detail and reliability. The selection of temporary samples respondsto obtaining data with a periodicity according to the dynamic condition of the problem andgenerates information synchronous to the national population censuses (2001, 2010 and 2022);we also work with hydrographic cartography and Digital Elevation Models, to identify trendslinked to topographic and hydrographic conditions. Integrating these variables in a MulticriteriaMatrix - through the use of GIS - allows us to integrate environmental, spatial, andsocioeconomic variables to study the close relationship between invasion-succession patternsand urbanization patterns. Our approach reconstructs this problem as a complex and dynamicprocess, from which it is possible to infer medium-term development trends. Through thistransdisciplinary analysis, a critical environmental process becomes a direct indicator of thecapacity of urbanization to transform the landscape on a regional scale. This is strategic data,not only to develop more effective protocols to remedy the impact of the invasion on the nativeforest, but also to generate situated knowledge about the urban-environmental dynamics of(re)production of the regional landscape, promoting more sustainable regional policies.