The production and fate of grasslands in Masai-Mara National reserve, Kenya

Abstract

A quantitative study of grassland standing crop and the losses through large herbivore offtake, tourist off-road driving. and fire was conducted in Masai Mara National Reserve for approximately one year. The Harvest method and Pin Frame Technique were used for biomass and cover determinations. Biomass was highest in June which was the end of the wet season, while it was lowest in the dry season. The highest green biomass in the wet season was 6494 kgha -1 in the western sec tion of the res erve, whiIe the lowest biomass, 17il -1 kgha ,occurred at the northeastern peripheral habitats grazed by domestic Livestoc'k , In October, green biomass decreased to , -1 -1 2723.2 kgha and 1175.2 kgha , for the two areas, respectively. Local rainfall patterns probably affected the trends in standing biomass The Serengeti migratory sp~cies mean plot occupance was 88.7 percent in the dry season, wh i le that of the resident wildlife species was 12.26 percent. In the wet period, the permanent exclosure plot green biomass was reduced by 20.60 percent through grazing by large herbivores, as compared to 8S.20 percent in the dry season when the Serengeti mi;ra~ts occupied the reserve. The effect of tourist off-road driving was very small but the aesthetic quality of the reserve was adversely affected. Fire alone removed 89.96, 79.77 and 52.32 percent of the standing crop from the tall, mixed tall and medium, and short grassland types, respectively. This represents considerable loss, yet incidents of wild fire have decreaseJ over the Serengeti-Mara . ecosystem since the 19605. Thus total losses may have decreased.