Contribution of Landform Analysis to the Study of Vegetation in Arid Zones (Cerro Zonda, San Juan, Argentina)

The aim of this work is to expand on the traditional method of examining the properties of the landforms and vegetation separately, considering that variations of geomorphological processes explain the vegetation distribution patterns. The methodology combines the analysis of Google Earth images, the processing of DEM and exhaustive field work. The geomorphological analysis five units: (a) Pediment of mountain upland; (b) Active landforms; (c) Inactive landforms; (d) Inactive landforms raised by neotectonic activity and (e) Lacustrine landforms. The vegetation cover does not exceed 40%, significant differences are found between the various geomorphological units. Said relationships were attributed to factors such as terrain roughness and slope landforms. Terrain roughness was the most significant variable for explaining which the areas are with a higher diversity index. The highest values of roughness were identified in active landforms and pediment of mountain upland. As regards slope landforms, slope exerts positive control over the vegetation cover. The properties of the landforms describe spatial changes in the development of the plant communities and show the consequences of geomorphological changes over such native vegetation patterns. It is deemed essential to combine a geomorphological analysis as a complement for understanding the vegetation patterns in arid zones.