Life history variation and demography of the invasive plant Eschscholzia californica Cham. (Papaveraceae), in two altitudinal extremes, Central Chile

Resumo

In this study, we compared demographic responses of Eschscholzia californica populations located at different altitude,
under the basic assumption that altitudinal gradients impose environmental limitation to the spread at the upper edge of the
gradient. We detected significant differences among populations either in terms of life history attributes and the finite rate
of increase. In general, coastal population expressed higher finite population rates than mountain populations, although
these differences were not statistically significant. Mountain populations (Corral Quemado and Farellones) expressed a
finite population rate not significant different of 1. These result suggest that at the upper front of invasion the species is in a
demographic equilibrium because in spite of we detected a higher plant fecundity, there exist ecological constraints a seed
stage level. We proposed to address more specific studies assessing from one hand, seed movement from lower altitudes
and the efficiency of domestic cattle as biotic vector; we also propose to examine the feasibility of this species to establish
positive interactions with cushion plants, and therefore to expand its geographic range due to this facilitation effect.