Distribución vertical de raíces y raicillas en dos páramos andinos funcionalmente contrastantes / Vertical distribution of roots and rootlets in two contrasted functionally andean paramus

Abstract

Se presentan resultados correspondientes a la distribucion vertical de las fitomasas de raices y raicillas en parcelas de agricultura tradicional y de recuperacion por barbecho sucesional en dos paramos andinos venezolanos funcionalmente contrastantes. Los resultados demostraron que, en el paramo de Gavidia, climatica y edaficamente menos tensionado, las fitomasas de raices y raicillas fueron significativamente mayores en la capa de 0 - 10 cm, mientras que en el de Apure, mas tensionado, la distribucion vertical de las fitomasas radicales resulto mas uniforme, ganando mas en profundidad, debido aparentemente, a un mecanismo natural de proteccion contra el frio y la desecacion. Se comparan los resultados con otros similares obtenidos en ecosistemas de paramos, bosques tropicales, pastizales y sabanas tropicales. Palabras clave: Andes, micorriza arbuscular, topografia, sucesion vegetal, Venezuela ABSTRACT Some results are presented corresponding to the vertical distribution of root and rootlet phytomass in traditional agricultural plots and successionally recuperating fallow plots in two Venezuelan functionally contrasting, Andean paramus. The results evidenced that in Gavidia paramus, showing less stressed climate and soils, root and rootlet phytomass were significantly larger at the 0 - 10 cm soil layer, while in Apure paramus, with a more stressed soil and climate, the vertical distribution of root phytomass was more uniform, reaching a larger depth. This last was consequence apparently to a natural mechanism of protection against cold and desiccation. The obtained results are compared with similar ones obtained at paramus, tropical forest, and tropical grassland and savanna ecosystems. Key words: Andes, arbuscular mycorrhiza, plant succession, topography, Venezuela PDF