Abstract

Estimation of the surface of microthermal plant formations in Peru at the beginning of the 20th century.

In 1922, the first “Phytogeographical Map of Peru between 5° and 17° S”, prepared by Augusto Weberbauer (1871-1948), was published in Germany. In this map, with a scale of 1:3'000,000, in geographic coordinates, and whose cartographic basis was the Map of Peru by Antonio Raimondi (1824-1890), Weberbauer captured a large part of the Peruvian territory by identifying and classifying 25 plant formations. Within these formations are the microthermal plant formations, which are generally found above 3,400 meters above sea level and with a wide latitudinal distribution throughout the Peruvian Andes due to the strong pressure they are currently suffering due to the sum of the change in global climate and anthropic impacts, becomes more relevant in its scientific study. In this context, through the georeferencing, digitalization, and geoprocessing of the attributes of the said historical map, using the ArcGIS program ver. 10.4 of the current methods of geographic information systems; the surface of such microthermal plant formations was estimated: (1) Tolar microthermal alternating with the typical high Andean formations; (2) Typical high Andean formations; (3) Herbaceous steppe (Pajonal) microthermal, always green or almost always green without or almost without trees; (4) Glaciers and perpetual snow. Considering the current political and administrative division of the country, an area of 18'011,056.87 ha was obtained for the set of microthermal formations, distributed as follows (in ha): (1) 3'197,574.02; (2) 11,012,642.64; (3) 3,263,249.49; (4) 537,590.71. In the department of Puno, with 3'058,684.02 ha, the largest area was recorded. These findings constitute a valuable source for any researcher or institution interested in this subject, which will be able to superimpose and make comparative approaches. For example, data on the estimated area of glaciers and perpetual snow can help many contemporaries analyzes climate change and deglaciation.