Effect of NAA concentrations on rooting of hardwood cuttings of Croton urucurana Baill., Tabernaemontana catharinensis A. DC. and Paullinia elegans Cambess.

Abstract

Human activities intensification produces severe variations in natural landscapes that could produce changes in species distribution. In Buenos Aires province, plants and animals that extended their habitat to the south were recorded. Here, we analyzed the expansion of Glinus radiatus, Guilleminea densa and Thalia multiflora, which are actually found more than 250 km far from the southern limit of their known location. Specimens were collected in Azul, Las Flores and Rojas, and then we reviewed the existing bibliography to locate previous records and discuss the causes of their expansion. Among the hypotheses that could explain the progress of these species, regional changes in rainfall and temperature stand out. Its also possible that previously published restricted location is due to insufficient survey, or specimens found could constitute relict populations, or have expanded favored by anthropogenic corridors.