Resumen

FERNANDEZ, Rubén  y  MERELES MENESSE, Gustavo. Analysis of the Spatial Distribution of Vegetation Patches in Chaco Sand Dunes: Possible Indicators of Catastrophic Regime Shift. Rep. cient. FACEN [online]. 2023, vol.14, n.1, pp.78-90. ISSN 2222-145X.  https://doi.org/10.18004/rcfacen.2023.14.1.78.

Catastrophic regime shifts in ecosystems are generally difficult to predict and often leads to negative ecological and socioeconomic consequences. In addition, they are generally difficult to reverse; desertification is an extreme and worrying example of this type of phenomenon. Despite the difficulty to predict these phenomena, in recent decades, theoretical-mathematical models that seek to capture the fundamental underlying mechanisms have been proposed, providing measurable indicators to identify the occurrence of these processes early. In dry ecosystems, models suggest that regime shifts to desert states can be related to the emergence of spatial patterns of vegetation, similar to those observed in phase transitions in physical systems. Combining satellite images analysis and simulations of a minimal model, the relationship between the characteristics of vegetation patches in Médanos del Chaco, one of the driest regions of Paraguay, and a catastrophic regime shift process to a desert state was analyzed. By studying the size distribution of vegetation patches, the presence of a scale-free pattern was identified, characterized by a power law distribution. In addition, high spatial correlation and spatial variance in the density of vegetation in relation to less dry regions was observed. The spatial characteristics. The spatial characteristics of the vegetation of Médanos del Chaco are compatible with theoretical quasi-critical conditions, suggesting that the region is close to a catastrophic regime change.

Palabras clave : ecosystems; catastrophic shifts; desertification; vegetation spatial patterns; Médanos del Chaco.

        · resumen en Español     · texto en Español     · Español ( pdf )