Conectividad estructural entre los Páramos de Guacheneque y Los Cristales, complejo Rabanal-río Bogotá, Colombia

Abstract

Structural connectivity is a measure of the spatio-temporal changes that affect the movement of species between elements of the landscape and availability of habitat; these modifications that have been documented for high mountain ecosystems in Colombia (páramo and high Andean forest) and are caused by agricultural and other economic activities that affect their integrity. The objective of this study was to evaluate the dynamics of the changes between plant cover (1987-2018) in the Guacheneque and Los Cristales páramos (Boyacá-Cundinamarca, Colombia). Images from Landsat 4 and 8 sensors were used. Pre and post-processing (supervised classification and field verification) were performed with ArcGIS and ERDAS. To estimate structural connectivity, metrics of landscape diversity, composition and configuration were calculated (Fragstats v4.2.1). Thematic reliability was 88%. Mosaic covering of pastures and crops (Mpc – 288 ha), dense grassland of firm ground (HdTf- 24 ha) and high open forest (Baa-165 ha), increased in 31 years, while dense bush (Ad) decreased 477 ha. The distance between tiles of Mpc and Ad increased (from 150.74 m to 170.70 m and from 196.96 m to 236.64 m respectively), and decreased for Baa (from 166.74 m to 159.27 m). Connectivity increased for Mpc and Baa, and decreased for Ad. The evaluated páramos make up a landscape with frequent and intensive land use, the effect of a long history of occupation of this territory. The dynamics of structural connectivity registered an increase in agricultural activities (páramo-grasslands transition). These have caused tensions and contradictions in the delimitation of páramos, a local loss of the natural area, a decrease in the average size of the tiles, and an increase in the perimeter /surface ratio distance between nuclei. The results corroborate the isolation and loss of habitat, the negative impacts on the biodiversity of the Rabanal-Río Bogotá páramos complex.