info:eu-repo/semantics/masterThesis
Scattered Trees in a pasture matrix enhance Phosphate deposition in the soil via rainfall redistribution: role of structural and morphological traits
Autor
Vásquez Sogamoso, Santiago
Institución
Resumen
ABSTRACT : Tropical ecosystems exhibit a natural limitation in soil nutrients, sufficient to limit productivity, particularly in the mountains ecosystems, where geomorphology and climate result in high rates of soil erosion, exacerbated with forest fragmentation and forest loss. This is particularly important in Phosphorous, a limiting nutrient in mountain ecosystems. Scattered trees in fragmented landscapes have been designated as key structures due to their ecological functions that improve the biophysical and biogeochemical conditions of the place and can potentially serve as starters for vegetation recovery. Previous studies have demonstrated the importance of precipitation redistribution and interaction with the canopy for nutrient inputs into forests, where tree species differ in their responses because of their specificity, trait configuration, and plant community competitive hierarchies. However, few studies have quantified the effect of functional traits, for different species of scattered trees, on their capacity to intercept and move phosphorus through precipitation partitioning. In this study, we determined the association between 12 plant functional traits and Phosphorous movement from the canopy into the soil in 20 individuals of five tree species scattered across a human-altered montane landscape in the Colombian Andes : Croton magdalenensis, Andesanthus lepidotus, Vismia Baccifera, and Quercus humboldtii, and a commonly-planted exotic species Eucalyptus globulus. We quantified PO₄-P concentrations in precipitation, throughfall, and stem flow in all trees for a group of 14 individual rainfall events. In general, PO₄-P concentrations in precipitation (0.33 mgPO₄-P/l) were lower that the net concentration (Nc) in all species. One particular species, C. magdalenensis, had significantly higher values of PO₄-P concentration in throughflow 1.27 mgPO₄-P/l and stem flow 7.01 mgPO₄-P/l. This condition potentially results from a particularly higher epiphyte, leaf area and trichome density in this specie, that potentially facilitate biogeochemical exchange and improve ecological functions associated with the early stages of forest recovery. Further, canopies can potentially transport phosphate to the soil, which helps to reestablish important biogeochemical processes in the first stages of restoration of degraded ecosystems.