Caracterización florística y estructural de la vegetación en la Reserva Natural de la Sociedad Civil El Diluvio (Villapinzón, Cundinamarca)

Abstract

The high mountain faces a serious crisis due to the transformation of its natural cover, particularly in the eastern sector, where 28% of the territory presents conflicts due to land overuse. The situation is especially critical in the Bogotá River basin, where pressure from agricultural activities, mainly potato cultivation, and cattle ranching have generated a 90% increase in ecosystem fragmentation between 2002 and 2018. In this context, the El Diluvio Civil Society Nature Reserve, located in Villapinzón, is a strategic area within the high mountain ecosystems due to its transition zones between the high Andean forest and the páramo. As part of the Chingaza- Sumapaz- Guerrero- Guacheneque and Cerros Orientales conservation corridor, the reserve plays a crucial role in water regulation and ecological connectivity, ecosystem services that benefit nearly 9 million inhabitants who depend directly on the resources of this watershed. The methodology was structured in three phases: preparation, field and systematization. In the preparation phase, secondary information was collected and reconnaissance surveys were carried out to define 30 plots distributed in three strata (forest, grassland and grassland-herbaceous). The plots were 100 m² in size for the forest stratum, 50 m² for the grassland stratum and 50 m² for the herbaceous and grassland-frailejonal stratum. During the field phase, the plots were delimited and structural vegetation data, botanical and soil samples were collected using georeferencing and measurement tools. Finally, in the systematization phase, climatic data were analyzed, soil samples were processed in the laboratory, botanical collections were identified in the UDBC herbarium and vegetation was classified using phytosociological approaches, complemented with ecological indices to characterize the structure of the vegetation units found. The syntaxonomic study of the vegetation in the El Diluvio Civil Society Nature Reserve identified four plant associations, including two new associations for the Eastern Cordillera: Clusio multiflorae-Weinmannietum tomentosae and Linochilo rosmarinifolii-Vaccinietum floribundi. In addition, the presence of the alliance Espeletio murilloi-Chusqueetum tessellatae, documented in the páramo of La Rusia in Duitama, was confirmed, and an undetermined alliance was described with two plant communities: Espeletiopsis rabanalensis with Aragoa cleefii and Espeletia barclayana with Scrobicaria ilicifolia. The structural and physiognomic analysis showed a distribution pattern determined by environmental factors, where the Clusio multiflorae-Weinmannietum tomentosae forests develop on poorly exposed slopes with deep soils rich in organic matter, while the Linochilo rosmarinifolii-Vaccinietum floribundi grassland is established on rocky and well-drained soils. In the pajonal-frailejonal, a sequence from steep areas to low slope areas with poorly drained soils was identified, which influences species composition. The unusual presence of forests at higher altitudes suggests ongoing regeneration processes, probably influenced by anthropogenic intervention. The identification of these patterns provides a fundamental basis for the development of ecological restoration strategies in the upper Bogotá river basin, contributing to the conservation of key ecosystems in the region.