Herder knowledge of landscape assessments in arid rangelands in northern Tanzania

Herder knowledge of landscape classification and environmental assessments in East Africa has been poorly documented. This study investigated how the Maasai traditionally classified and assessed landscapes for grazing resources in northern Tanzania. The Maasai herders classified seasonally grazed landscapes using socio-cultural folk systems, soils, topography and vegetation, management knowledge and seasons of grazing. Herders characterized landscapes of the grazing lands as degradable (orpora) or non-degradable (orkojita) in response to heavy grazing pressure, with reference to soils (ngulupo) and vegetation type. This categorization is used for regulating seasonal grazing across heterogeneous landscapes. Impacts of livestock grazing across seasonal grazed landscapes were evaluated in terms of herder perceptions and field data on plant species composition, richness, biomass and cover. According to the herders, degradation occurred in the Selela landscapes when traditional grazing systems were altered by crop cultivation. Herders used past experiences to determine shifts in plant species composition. The disappearance of key forage species and an increase in species less desired by livestock were used as indicators of degradation. The overall effect of land degradation was inferred from a decline in livestock productivity. The evidence suggests that descriptions of landscape degradation in terms of loss of grazing value for a particular livestock species might be more relevant than a general statement about rangeland degradation associated with pastoral land use. According to these findings, land use planners could incorporate herder knowledge with scientific methods to test the impact of management and promote community participation in rangeland monitoring. (c) 2005 Elsevier Ltd. All rights reserved.