LONG-TERM VEGETATION MONITORING IN THE SERENGETI-NATIONAL-PARK, TANZANIA

Several investigators have suggested that portions of the perennial grasslands of the Serengeti plains have recently been converted to annual-grass and shrub-dominated communities due to overgrazing and disturbances by wildebeest, which have increased 5-fold in population since 1961. Study sites that were described and mapped in the 1960s and 1970s were revisited in 1982 and their species compositions and community patterns compared to the earlier descriptions. No changes in species composition were found in any of the communities. Vegetational mosaic patterns in aerial photographic plots had not visibly changed in size, shape or position over a 10-yr period. The Zurich-Montpellier method used to describe the vegetation of several sites in 1972 was inappropriate for long-term vegetation monitoring. In is suggested that, in future, vegetational changes be monitored by recording the percentage cover of species in small, permanently marked plots. No evidence of range deterioration was found in the Serengeti grasslands.