paradox of plant height in an Andean giant rosette species

(1) Espeletia schultzii (Compositae), a perennial rosette species common above the treeline in the Venezuelan Andes, increases in mean stem height and maximum stem height with increasing altitude, whereas, in general, species occurring above tropical and temperate treelines decrease in size with increasing elevation. (2) Greater height in E. schultzii is the result of greater longevity, which may be caused by reduced interspecific competition, and by reduced intraspecific competition between pre-reproductive and adult plants. (3) In addition, selection at high altitudes may favour genotypes which produce longer-lived plants.