Incidencia del relieve en la estructura y composición vegetal de un bosque subandino en la Cordillera Oriental de Colombia.

Abstract

This study focused on analyzing the relationships between the topographic gradient and the distribution of plant communities in the sub-hygrophytic sub-Andean humid forest, considering four topographic units: Ridge, middle slope, low slope and the small valley of the Los Estoraques Unique Natural Area (ANULE), located in La Playa de Belén, in the department of Norte de Santander. For vegetation sampling, four plots of 100 m2 are established per topographic level using the quadrat method. Inventorying all herbaceous, shrubby and woody terrestrial plants with a diameter at breast height (DBH) ≥ 1 cm. True diversity indices (Hill Numbers) were estimated, as well as horizontal and vertical structure (Pretzsch A Index). The relationships between the plant communities of the topographic levels were analyzed using an NMDS and PCA. The results revealed that the low slope exhibited the greatest species richness, with 85 species, followed by the little valley with 68, the middle slope with 66, and the crest with 44 species. The similarity between the sites, based on the Bray-curtis and Sorensen index, was low, highlighting the presence of unique species in the little valley and low slope. Regarding the structure of the forest, it will be observed that the middle staircase presented greater dominance, heights and diversity of species compared to the other levels, while the crest recorded the lowest values in these aspects. Regarding the environmental variables, it was found that the slope is positively correlated with the diameter of the individuals and that there are significant differences in relative humidity between topographic levels. This finding emphasizes the importance of applying conservation strategies adapted to each topographic unit, recognizing its particularities and promoting the preservation of the unique biodiversity that characterizes each of them. In terms of conservation, topographic units can be useful for identifying critical areas for conservation and prioritizing conservation efforts in areas where biodiversity is high and/or threatened. Therefore, the careful selection of topographic units is a valuable tool for ecosystem management and conservation.