Determinación de la diversidad de órdenes de macrofauna del suelo en áreas de restauración de sabanas inundables sometidas a pastoreo y monocultivo de maíz (Yopal, Casanare)

Abstract

The flooded savannas of the Fundo Palmarito Civil Society Nature Reserve, in the La Unión district (Yopal, Casanare), are ecosystems that have been modified and subjected to intensive grazing and corn cultivation. These modifications influence the soil-plant-water relationship and, in turn, the diversity of soil macrofauna. The sensitivity of macrofauna to changes in land use defines this group as a biological indicator of soil quality and health. This study was developed using the TSBF (Tropical Soil Biology and Fertility) methodology for diversity estimation and comparison between land uses of macrofaunal orders. Sixty soil monoliths of 25x25x10 cm, distributed in three land uses: introduced cattle pasture, maize crops and conservation (gallery forest), were analyzed, where the presence of 16 orders and a total abundance of 2794 individuals were determined. The evaluation of true diversity according to land use showed that pastures had a higher richness (q0) and a higher diversity of dominant species, while forests had more rare species (q1), and the area with corn crops had the lowest richness and diversity. The analysis of indicator species by land use revealed that Blattodea, Gastropoda, Lepidoptera and Trombidiformes are indicators of gallery forest, and the infraorder Isoptera in dry sampling points. Ordination analysis with multivariate methods PCA and NMDS indicated that macrofaunal composition influenced by waterlogging conditions at the time of collection (R²=0.0838; p=0.010) and elevation (R²=0.1502; p=0.026). The above allowed testing and evaluating the use of macroinvertebrate communities in the monitoring of changes in soil quality associated with management practices, taking into account that reforestation activities will be implemented in the study area, which will be monitored.