Vanessa Cespedes #StopInvasoras

ALT Lesser black-backed gulls at Laguna de Fuente de Piedra in Málaga. / Víctor Martín Vélez

ALT The stochastic cusp catastrophe model fitted to the community trend, as a function of the stratospheric aerosol optical depth and flooding extension. A) the tipping point is the 1991 eruption of Mt.Pinatubo, which triggered a period of dry and cold winter conditions in the Southern Palaearctic until 1995. Before the tipping point, waterfowl community fluctuations were located in the upper stable branch of the surface. B) numbers of days of flooding in Doñana for 1995, at the end of a period characterized by dry and cold wintering conditions; and 1996, a climatically normal (wet and warm) year. The dynamic in year 1995 was evolving in the unstable (transient) branch of the surface. From 1996 on, the dynamics settled in the lower stable branch. C) temporal dynamics of community abundance evolving with respect to the asymmetry parameter (flooding extension) from the first (purple arrows) to the second stable state (green arrows) through the transient, unstable period (gray arrows)