Does intraspecific variability in plant functional traits drive invasive success in altitudinal gradients?

FERRERO M.C.; GURVICH D.E.; TECCO P.A.; LUNA L.; SAUR PALMIERI V.

Mar del Plata

Congreso; 2nd World Conference on Biological Invasions and Ecosystem Functioning; 2011

Grupo de Investigación y Educación en Temas Ambientales (GrIETA)

Understanding plant invasions dynamics and their potential impact on mountain environments is essential given the valuable ecosystem services these systems provide. By comparing the dominant native species of the upper belt of the Córdoba Mountains (Polylepis australis) and the main woody invader at those altitudes (Cotoneaster franchetii) this work aimed at (1) evaluating the existence of intraspecific variability in leaf and wood functional traits along the altitudinal gradient, and (2) comparing species? resources use strategies. Seven leaf and woody traits were measured on 20 individuals of each species, every 200 meters of altitude (between 1300-2100 m.a.s.l.). Micro-environmental characteristics surrounding each plant were also recorded. Through ANOVAs and using a principal component that summarized micro-environmental measurements as a covariate, we observed that Polylepis show significant differences in most attributes along the gradient (smaller leaves, with lower values of specific leaf area, leaf area: sapwood area, wood-saturated water content and inverse Huber value, with increasing altitude); while Cotoneaster show differences in three traits (specific leaf area, wood density and wood-saturated water content), but not linearly associated with altitude. A multivariate analysis considering the attributes of the altitudinal populations of both species suggests that Cotoneaster has less variability and a more conservative resource use strategy than Polylepis throughout the gradient. Given the low association with altitude, intraspecific variability along the gradient would not be underlying Contoneaster?s invasion success in this system. Assessing if the conservative strategy of Cotoneaster implies no reduction in resource availability in the system deserves specific appraisal.