Resumen

PEREZ QUINTERO, ÁLVARO LUÍS  y  WATTEIJNE CERON, BENICIA. Lichen Community Structure And Morphological Changes In The Genus Sticta (STICTACEAE) Associated To An Altitude Gradient. Acta biol.Colomb. [online]. 2009, vol.14, n.3, pp. 159-172. ISSN 0120-548X.

Lichen’s growth and distribution are conditioned by various environemental factors, altitude being an important one. In the Cordillera Oriental of Colombian Andes, there haven’t been studies on lichen’s altitudinal zonation. We studied the variation on lichen community structure along an altitudinal gradient (2000- 2600 m) in PNN Tatamá, we found diversity diminishes as altitude increases, this being a variation from what’s generally found in lichen community behavior. At low altitudes, the community was conformed by fruticose lichens (30% cover at 2070 m and 0% at 2560 m), and by foliose lichens at high altitudes (15% cover at 2070 m and 43% at 2560 m). Altitude, besides influencing lichen’s community structure, may affect their development and morphology. In the foliose genus Sticta we found intraspecific variation on cyphellae (gaseous exchange organs) density associated with altitude, a significant effect of altitude on cyphellae density was found for the species S. andensis and S. gyalocarpa (ANOVA p value= 0.008 and 0.05 respectively). This shows an adaptation mechanism of these organisms to the environmental changes given with altitude.

Palabras llave : Altitudinal gradient; epiphytic lichens; lichen community; Sticta sp.