Relación entre la variación de la vegetación por diferente historia de uso y los componentes orgánicos del suelo en el noreste de la Patagonia

Abstract

In the NE of Patagonia, there is the transition area between the Monte and Espinal phytogeographic provinces, where the main productive activities that influence the system are dry agriculture and extensive livestock. The objective of the work was to evaluate the relationship between the variation of the vegetation due to different history of use, the quality of the mulch and the concentration of organic carbon in the soil in said transition. 6 sites with contrasting situations of vegetation cover were selected, in which information about their history of use was collected, and also 5 ten-by-ten plots were determined with intervals of no less than 30 m. In these plots, vegetation data was recorded and mulch and soil samples were obtained at a depth of 0 – 0.30 m. Through the processing of the samples and the analysis of the data, the floristic composition and the structural properties of the vegetation, the quality of the mulch and the concentration of Organic Carbon (CO) in three fractions of the soil are determined. The history of use of each place would be a determining factor for the state of the vegetation and the soil. The structure of the vegetation varies in relation to the use of the land, but not the floristic composition, since the latter did not present consistent variations along the geographical gradient of the study area. The quality of the mulch deposited on the soil is related to the floristic composition. The concentration of CO in the soil is directly related to the history of use, which in turn influences the vegetation variables. Although a positive relationship was found between woody cover and CO in the soil, sites with a high intensity of use presented lower CO values. The different forms of management can reduce the impact of human activities on the native vegetation The implementation of "cortaderas" is highlighted as a tool for soil quality and maintenance of plant species, favoring the conservation of biodiversity and ecosystem services.