摘要
Grazing livestock is an important asset to the livelihoods of people in most semi-arid environments, where natural resources cannot be used directly for human consumption. However, overgrazing commonly reduces pasture productivity and therefore threaten people's long-term food security. Ligneous and herbaceous vegetation on grazed and ungrazed sites in the Hajar Mountains, Oman, was studied to evaluate the possibilities of improving pasture management to maintain fodder production. Foliar biomass was 3–6 t dry matter ha−1 on the grazed and ungrazed plateau areas and 41 t dry matter ha−1 in the shallow valleys. Herbaceous yields changed over seasons and contributed ≤13 % to accessible biomass, stressing the importance of ligneous foliage for livestock nutrition in particular during dry periods. While botanical composition and biomass of the vegetation differed between grazed and ungrazed sites, canopy cover and biomass yields were similar in a 15-year old enclosure and on a naturally ungrazed mountain plateau. Despite the climatic conditions, pastures encompass characteristics of equilibrium systems, where vegetation is strongly influenced by grazing livestock but recovers in its absence. The sustainable use of the natural fodder resources through improved pasture management is therefore a valuable alternative to intense supplement feeding or the introduction of zero-grazing management.