“…Lignin found in tussock roots increased with altitude (P < 0.001), while the same trend was observed for acaulescent rosettes and cushions. The high lignin concentration in the species located in the high catchment could explain the survival of certain species to such relatively hostile environment, filled with loose stones, sandy soil, low soil water-holding capacity and low nutrient content (Körner, 2003;Molau, 2004;Rada et al, 2001). Additionally, they have to cope with climatic conditions of low oxygen concentration, low rainfall, high solar radiation, strong wind abrasion and night frost (Baruch, 1984).…”